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[Display omitted] • Activated carbon and porous carbon nanofibers were obtained from PAN. • N and O containing functional groups promote the VOCs adsorption. • Adsorption energies and electrostatic interaction of AC and CNFs were analyzed. • The adsorption of VOCs on inner and outer sites of CNFs were compared. The adsorption technology has been considered as an effective and economical strategy to control volatile organic compounds (VOCs) through various types of porous materials. As two potential porous materials, activated carbon and carbon nanofibers were synthesized as VOCs adsorbents. In order to investigate the difference in the adsorption of VOCs between activated carbon and carbon nanofibers, the specific surface area, pore structure and chemical functional groups of VOCs adsorbent were analyzed. In particular, the carbon nanofibers (CNF) activated at 800 ℃ showed an excellent specific surface area (2524 m2·g−1), abundant pores (1.66 mL·g−1), and rich functional groups (N: 8.29 at%). Meanwhile, the carbon nanofibers had a better adsorption performance for acetone (1069.82 mg·g−1) and toluene (427.72 mg·g−1) than activated carbon materials. Furthermore, the theoretical calculations were conducted to reveal the mechanism of favorable adsorption on the CNFs. The theoretical adsorption energies of CNF are −31.9 kJ·mol−1 (acetone) and −67.5 kJ·mol−1 (toluene), respectively, which have more favorable adsorption sites and stronger charge redistribution than activated carbon. This research guided the approach to obtain the porous carbon nanofibers and provided the evidence for CNFs (curved carbon) exhibiting a better adsorption ability to VOCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A theoretical framework for the evaluation of flexible anode materials is established. • The mechanical property of Janus MXene is comparable with that of pristine MXene. • A constant diffusion barrier on Ti 2 COF under strain is suitable for a flexible anode. Two-dimensional transition metal carbides (MXenes) have received tremendous attention because of their great promise in flexible energy storage. Although surface engineering plays an important role in regulating the properties of MXenes with the development of synthesis technology, an atomistic design of surface diversity for desired functionalities is generally limited by purely unified surface termination. Herein, the Janus MXenes consisting of different surface terminations are proposed for flexible anodes through first-principles calculations. Taking Ti 2 C TT' (T , T' = O, F, or OH) as an illustration of Janus MXenes, critical strains, ideal strengths, Li-ion diffusion barriers, equilibrium voltages, and theoretical capacities are determined and used as descriptors to evaluate the properties of flexible anodes. These Janus MXenes exhibit high critical strains and ideal strengths, indicating their mechanical flexibility. The strain-independent Li-ion diffusion barrier of Ti 2 COF suggests its fast Li-ion transport even suffering from mechanical deformation, endowing its application potential in flexible anodes. These results establish a theoretical framework for the comprehensive evaluation of flexible anode materials, providing a theoretical scheme for designing flexible anode materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two DACs were screened to replace Pt(1 1 1) as promising candidates from 406 DACs. • Proposed DACs with the excellent HER performance was determined in detail. • Six ML models with four kind of input features were investigated and screened. • Artificial neural networks with simple input features showed the highest accuracy. Dual-atom catalysts for hydrogen evolution reaction have received widespread attention, but precise screening and prediction of high-performance catalysts through simple methods remains a challenge. In this study, we perform high-throughput density functional theory (DFT) calculation and machine learning (ML) to screen and predict the transition metal dual-atom catalysts with N-doped graphene support (TMDACs) for acidic hydrogen evolution reaction (HER). The Fe_Zn and V_Fe DACs were proposed to be the most promising candidates for Pt-based catalyst toward acidic HER from 406 TMDACs, based on the characteristics of HER activity, formation, thermodynamic stability, abundance, environmental friendliness. The Fe_Zn and V_Fe DACs with excellent HER performance is due to the synergistic effect deriving from the interaction between H and dual metal atoms in TMDACs. By determining 6 different ML models with four kind of input features, we find the artificial neural networks (ANN) model can predict the HER performance of TMDACs most accurately only using simple input features, including one-hot-encoding of atomic number and Gibbs free energies of transition metal single-atom catalysts. This work not only proposed the potential TMDACs with high HER performance, but also verified that the ANN model can accurately predict the HER activity of diatomic catalysts with simple input features. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adsorption of pollutant gases was examined on g-C3N4 surface using DFT calculations. • S-containing gases showed stronger interaction with surface than N-containing gases. • Work functions change adequately to provide detectable signs. • The recovery times were calculated to confirm the sensor performance. • Transmission coefficients calculated using NEGF method increase after gas adsorption. Rapid detection of harmful airborne substances caused by daily activities and industrial activity is vital. In the current study, the applicability of s-triazine based g-C 3 N 4 nanosheet as a potential sensor for environmentally dangerous gases, NO, N 2 O, NO 2 , SO, SO 2 , and SO 3 , was investigated using the density functional theory and non-equilibrium Green's function (NEGF) method. Sulfur-containing gases exhibited stronger interactions with the surface. The obtained adsorption energies are in the range of −0.21 to −1.13 eV, which is associated with charge transfer in the range of −0.09 to −0.29 e. The molecules' overall structures are preserved during the adsorption process. The sensitivity of the surface to the adsorbed molecules was confirmed by analyzing the work function changes and calculating the transmission coefficients using the NEGF approach. All adsorbate species, except SO 3 , have short recovery times of up to 3.9 s at room temperature, proving the efficiency of this surface as a viable sensor material. Furthermore, by analyzing the humidity impact, the g-C 3 N 4 ability as a sensor in more realistic conditions was also validated. The results indicate that the g-C 3 N 4 surface can be an excellent candidate for toxic gas detection with high selectivity and sensitivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 2 O 3 exhibits excellent chromium removal efficiency (86.29 %). • Fe 2 O 3 can inhibit the formation of highly toxic hexavalent chromium. • O and Fe atoms of Fe 2 O 3 surface serve as the active sites for Cr adsorption. • CrCl formation is the rate-determining step of CrCl 3 formation on Fe 2 O 3 surface. Fe 2 O 3 is one of the main compositions of sludge-incinerated fly ash and shows reactivity for chromium removal from flue gas in the incinerator. Experiments and density functional theory (DFT) calculations were performed to investigate the high-temperature reaction chemistry of chromium and chlorine over Fe 2 O 3 within fly ash. Fe 2 O 3 exhibits outstanding chromium removal efficiency of 86.29 % in N 2 atmosphere. The presence of HCl obviously inhibits chromium removal, the inhibition effect increases with increasing HCl concentration. Fe-Cr composite oxides are the main products of chromium-Fe 2 O 3 high-temperature reaction. Chromium within the reaction products in N 2 or HCl-containing atmosphere mainly exists in the form of Cr3+. O 2 addition leads to the formation of a small amount of Cr6+. Fe 2 O 3 exhibits excellent inhibition performance of chromium oxidation. DFT calculations suggest that CrCl 3 and CrO 2 Cl 2 are chemically adsorbed on Fe 2 O 3 surface. Both O and Fe atoms of Fe 2 O 3 surface serve as active sites for chromium adsorption. HCl is dissociatively adsorbed on the Fe 2 O 3 surface, and reacted with chromium to form CrCl 3. CrCl 3 formation on the Fe 2 O 3 surface is dominated by a four-step reaction pathway: Cr(ads) → CrCl(ads) → CrCl 2 (ads) → CrCl 3 (ads) → CrCl 3. CrCl formation is the rate-determining step with the energy barrier of 39.51 kJ/mol. [ABSTRACT FROM AUTHOR]

[Display omitted] • A RuSe 2 /MoSe 2 heterostructure was prepared for HER in alkaline media. • RuSe 2 nanoparticles was uniformly dispersed onto MoSe 2 rods. • The charge redistribution over interface of RuSe 2 /MoSe 2 facilitated charge transfer. • The RuSe 2 /MoSe 2 heterostructure exhibited good performance for HER in alkaline media. • DFT was performed to investigate the mechanism behind performance improvement. Despite being regarded as a favorable substitute for platinum-based catalysts in hydrogen evolution reaction (HER), molybdenum diselenide (MoSe 2) exhibits inferior electrocatalytic performance due to its inadequate conductivity and limited active sites. However, employing molecular engineering for modification holds great potential in significantly enhancing its performance, yet it still poses significant challenges. Herein, an interface engineering strategy was adopted to obtain RuSe 2 modified MoSe 2 composite catalysts (RuSe 2 /MoSe 2). In alkaline media, RuSe 2 /MoSe 2 exhibited a reduced overpotential of 147.8 mV at 10 mA cm−2 comparing with pristine MoSe 2 (351.8 mV). Experimental findings and density functional theory (DFT) calculations indicated that increased conductivity, enhanced hydrophily and optimized adsorption free energies of hydrogen contribute to its enhanced HER activity. This work opens up an interface engineering strategy for designing more efficient selenide-based electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The potential of 5 types of graphene as carriers for [N 1111 ][2-Op] in CO 2 capture were theoretically investigated. • The impact of different graphene surfaces on the properties of [N 1111 ][2-Op] were evaluated. • The advantages of B/N-doped fluorinated graphene as an efficient material for enhancing CO 2 adsorption were highlighted. • The findings contribute to the selection of suitable carrier materials for CO 2 capture. Graphene carriers can improve the properties of ionic liquids and enhance their CO 2 capture performance. Density functional theory calculations were employed to evaluate the feasibility of utilizing graphene as a carrier material to enhance the CO 2 adsorption capacity of hydroxypyridine-based ionic liquids (ILs). The results indicated that BN co-doped fluorinated graphene represented a promising carrier material capable of weakening the interaction between cations and anions while enhancing the charges of O and N in the anionic species of ILs, thereby increasing the adsorption capacity of ionic liquids for CO 2. Furthermore, the microstructure and properties of the graphene-ILs composites were explored. Doping atoms in graphene were found to induce alterations in the distribution of surface electrostatic potential, influencing the adsorption sites of ionic liquids and their properties. Compared to hydrogen-terminated graphene, fluorinated graphene was a more stable carrier material due to its higher binding energy with hydroxypyridine-based ILs. The higher binding energy was not derived from the direct interaction between doped atoms and ILs, but rather from the impact of doped atoms on the electronic structure of graphene. In methanol solvent, the adsorption of ILs on various graphene surfaces was a spontaneous exothermic process, indicating the feasibility of material preparation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ultra-long Rb 0.17 IrO 2 nanowires with both amorphous and crystalline features by interfacial oxidation. • Rb 0.17 IrO 2 exhibits outstanding water oxidation activity with an OER current density of 10 mA cm−2 at 330 mV. • Rb leaching behavior can gradually increase the O 2p center of the interface. • Rb 0.17 IrO 2 nanowires exhibited good activity for OER due to the O-2p centers and increased Ir-O hybridization as a result of partial amorphization. Recently, surface reconstruction derived from Ir-based derivatives could achieve satisfactory oxygen evolution performance. Herein, ultra-long nanowire hollandite structured Rb 0.17 IrO 2 was synthesized and a nano-amorphous layer with a thickness of ∼1.5 nm was achieved by interfacial oxidation treatment. The prepared catalyst exhibits outstanding water oxidation activity with an oxygen evolution reaction (OER) current density of 10 mA cm−2 at 330 mV for robust continuous operation in acidic media. Through the spectroscopic and density functional theory (DFT) theoretical calculations, we demonstrate that the nano-amorphous layers induced by interfacial oxidation on the one-dimensional (1D)-nanowire surface have enhanced O-2p centers and increased Ir-O hybridization compared to the bulk Rb 0.17 IrO 2 phase, which essentially balances the adsorption energy of the intermediates. Effectively incorporating surface reconstruction behavior could significantly improve catalyst activity. This work effectively combines 1D Ir-based materials and surface reconstruction, which provides a strategy for the subsequent full utilization of Ir-based materials applied on OER process. [ABSTRACT FROM AUTHOR]

Reliable and sustainable energy storage systems are crucial for a renewable energy future. The ultrahigh theoretical specific capacity and energy density of lithium–sulfur batteries (LSBs) make them one of the most promising next-generation battery technologies. However, their large-scale applications are seriously limited by rapid capacity fading and poor Coulombic efficiency owing to the shuttling of lithium polysulfides (LiPSs). Herein, we investigate nickel phosphide (Ni 2 P) as an effective host material to realize high-performance LSBs based on first-principles density functional theory (DFT) calculations. Our calculated adsorption energies of the LiPSs species reveal that the Ni 2 P(0001) surface possesses moderate to high adsorption strength and the adsorption process is facilitated via charge transfer from the LiPSs to the interacting Ni 2 P(0001) surface atoms. Due to the strong interactions between Ni 2 P(0001) and LiPSs (Li 2 S x , x = 1, 2, 4, 6 and 8), we observe elongation of the intramolecular Li–S bonds in LiPSs upon their adsorption. The stronger adsorption of Li 2 S coupled with its spontaneous dissociation suggests a faster charging process could occur on the on Ni 2 P(0001) surface. These results demonstrate that Ni 2 P can provide effective anchoring sites for the soluble LiPSs, potentially having implications for the design of electrodes for practical LSBs. [Display omitted] • Accurate first-principles characterization of LiPSs adsorption geometries. • Description of active sites on Ni 2 P (0001) surface. • Elucidation of charge transfer dynamics and anchoring behavior. • Findings on LiPSs catalytic degradation mechanisms and redox kinetics. [ABSTRACT FROM AUTHOR]

[Display omitted] • A graphene-loaded transition metal single-atom catalyst doped with nitrogen atoms was designed. • Five catalysts with excellent NRR catalytic performance were screened from 406 catalysts, with the lowest limiting potential of 0.31 V. • Screening strategy: ① The adsorption energy of N 2 ＜ 0.5 eV; ② The free energy barriers for the first and last hydrogenation reactions ＜ 0.4 eV; ③ The free energy of desorption of NH 3 ＜1 eV; ④ Better NRR selectivity than HER. Nitrogen reduction reaction (NRR) is necessary as an environmentally friendly and sustainable method for producing NH 3 in the context of the energy crisis and increasing environmental concerns. Efficient catalysts play an important role in the NRR reaction. In this work, a high-curvature tetracoordinate transition metal (TM) nitrogen-doped graphene single-atom catalyst was designed and five candidate catalysts with excellent performances were selected from 406 models through a combination of high-throughput screening and density functional theory calculations. Using seven different coordination types MC 4 , MC 3 N 1 , MC 2 N 2 -1, MC 2 N 2 -2, MC 2 N 2 -3, MC 1 N 3 and MN 4 , of which VN 4 (side-on) with four N-atom coordination has the lowest limiting potential of 0.31 V and the competing Hydrogen Evolution Reaction (HER) was suppressed. This work provides guidance for the development of efficient NRR catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A DFT study was performed to investigate the catalytic activity of M 2 @g-C 6 N 6 , (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Hf, Ta, W) for the urea synthesis by reducing N 2 and CO 2 (NCR). • The preference of CO 2 adsorption and the co-adsorption of CO and N 2 , which then the key intermediate *NCON is generated through the C-N coupling process. • Ta 2 @g-C 6 N 6 could be one of most promising catalysts for electrocatalytic NCR activity. Urea is an important nitrogen fertilizer and chemical raw material. Nowadays, searching for a harmless direct urea synthesis catalyst to electrochemically co-reduce N 2 and CO 2 gas for green urea synthesis under environmental conditions and avoiding the traditional ammonia synthesis pathway is a challenging research area. Here, a density functional theory (DFT) study was performed to investigate the catalytic activity of bimetallic doped graphite carbon nitride electrocatalysts (M 2 @g-C 6 N 6 , M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Hf, Ta, W) for the urea synthesis by reducing N 2 and CO 2 (NCR). The preference of CO 2 adsorption and the co-adsorption of CO and N 2 , which then the key intermediate *NCON is generated through the C-N coupling process. Three possible limiting steps are revealed, then the surface oxidation or hydroxylation and the competitive side reactions of NRR and HER were compared. The calculated results indicate that Ta 2 @g-C 6 N 6 could be one of most promising catalysts for electrocatalytic NCR activity with limiting potentials of −1.01 V, which could effectively restrict surface oxidation or hydroxylation and suppress the competitive side reactions of the nitrogen reduction reaction (NRR) and hydrogen evolution reaction (HER). [ABSTRACT FROM AUTHOR]

[Display omitted] • Spin-polarized DFT assessed O-CoMoSe 2 : stability, d -band, and reaction kinetics. • Partial oxygenation enhances CoMoSe 2 catalytic activity by optimizing electron transfer. • Lower Gibbs energy: alters by d -band energy level • Lower overpotentials at various active site: involvement of four electron mechanism • Screening of solvent effects on reaction pathway for OER and ORR. Efficient, stable, and cost-effective electrocatalysts for hydrogen evolution, oxygen evolution, and oxygen reduction reactions have been in demand for decades. Recently, layered transition metals (Co, Mo, Ni, and Fe) and chalcogen compounds (S/Se/Te) gained prominence in catalysis and device studies. Density functional theory identified the covalency of Co and Mo, oxygenated bimetallic selenium bond, crystal structure distortions, and adsorption properties as crucial for enhanced electrocatalytic activity. Hybridizing the Co and Mo d -orbitals around the Fermi level of 0.463 eV improves bonding with metal surface-adsorbate intermediates validated by partial density of states. Oxygenated cobalt molybdenum selenide (O-CoMoSe 2) (2 1 0) exhibited remarkable electrocatalytic properties at various active sites, with Gibbs free energy and theoretical overpotential at an active site of Co = 0.086 eV, 0.41 V, and Se = 0.50 V. [ABSTRACT FROM AUTHOR]

Silicon etching has found widespread application in the semiconductor industry over recent decades. However, the optimization of the utilized procedures has relied mainly on trial-and-error experimental approaches. Very few works have to-date tackled its atomistic simulation, and the mechanism behind the silicon removal remains poorly understood. In this work, we simulate all possible reaction steps of the etching process with Density Functional Theory, and we build a kinetic Monte Carlo model to study its dynamics. We characterize the energetics of the reaction mechanism, estimate the etch rates as a function of HCl pressure and temperature, and unveil the dominant gas-phase products for the different operando conditions, providing a solid theoretical background for process optimization. We find a remarkable agreement between our results and the reported experimental data. [Display omitted] • Investigation of the mechanism of Si etching with a multiscale modelling approach. • Model validation with a remarkable agreement with experiments. • Low-temperature etching can be performed at low HCl partial pressure. • Temperature becomes an inefficient knob to tune the etch rate above 1200 K. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalytic Enhancement with Small Bimetallic Clusters supported on ZrC and TiC(0 0 1) • Spillover Phenomenon and Thermodynamically Favorable Migration of H. • Barrier-Free or Low-Energy Dissociation using Bimetallic clusters supported on TMCs. • Polarity-Driven Activation Using Bimetallic Cluster on TMCs for activate and dissociate H 2. The adsorption and dissociation of hydrogen on bimetallic clusters of Au x Pt 4-x supported on TiC (0 0 1) and ZrC (0 0 1) surfaces, has been studied using periodic boundary density functional theory (DFT). Simulations reveal that H 2 exhibits moderate adsorption energies on Au x Pt 4-x /TMC (TM = Ti and Zr) systems and dissociates with a tiny barrier comparable to archetypal catalyst such as Pt (0 0 1). The incorporation of two different metal atoms (Au and Pt) in the cluster results in a noticeable enhancement of catalytic activity compared to clusters of equivalent size composed of pure metals like Pd, Cu, and Pt when deposited on TiC (0 0 1). Furthermore, our calculations reveal that the adsorbed H atom on the AuPt 3 cluster is prone to spill over the C sites on both surfaces, and the migration of hydrogen atoms on both supports is thermodynamically favorable. In essence, our results provide compelling evidence that when Au x Pt 4-x clusters are supported on surfaces with a significant degree of polarity, as TMCs, the complete system H 2 /Au x Pt 4-x /TMC can efficiently activate and dissociate H 2 concurrently, highlighting the potential for enhanced catalytic efficiency in hydrogenation reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • PHSN Enhancement: Novel cage-like PHSN boosts polyimide materials' AO resistance. Key for aerospace. • Molecular Dynamics: Reveals PI/PHSN's AO resistance via reaction pathways and surface analysis. • DFT Analysis: Uses density functional theory to identify AO reaction sites on PHSN, inhibiting volatilization. • Mechanism Discovery: Cage-like PHSN transforms AO to SiO 2 , offering molecular-level protection. • Aerospace Applications: Provides insights for AO erosion protection in spacecraft materials and design. Polyimide (PI) has excellent insulating properties and is widely used in aerospace electrical transmission devices and equipment. Polysilazane coatings have demonstrated excellent resistance to reactive atomic oxygen (AO). However, the understanding of the atomic oxygen erosion mechanism for polymer materials mixed with polysilazane components remains limited. In this study, a cage-like polyhydroxysilylazane (PHSN) primarily composed of silicon and nitrogen was designed. Two PI/PHSN hybrid structures were established, and their resistance to AO erosion, reaction pathways, and surface separation products were explored through reactive molecular dynamics simulations. Density functional theory (DFT) was employed to analyze the molecular orbitals of PHSN at different stages, predicting possible reaction sites for AO. The natural binding of generated small molecular fragments to PHSN side chains was studied through binding energy, revealing the volatilization inhibition mechanism of these small molecular fragments. Results indicate that the added cage-like polyhydroxysilylazane enhances the polymer's resistance to AO erosion by absorbing AO and converting it into SiO 2. This study explores the protective behavior of PHSN nano-cages at the molecular level, providing a new perspective for the design of AO erosion protection systems. [ABSTRACT FROM AUTHOR]

The long-standing barrier of the efficiency-voltage trade-off in magnesium air battery has hindered its widespread adoption. We surmounted this obstacle by pioneering a novel active learning framework tailored to screen novel magnesium anodes. The framework discovered a novel anode, Mg-1Ga-1Ca-0.5In, with exceptional performance. The excellent performance of Mg-1Ga-1Ca-0.5In is attributed to the concepts of "grain boundary activation" and "intra-grain inhibition". [Display omitted] • A novel active learning framework was proposed to design magnesium anode. • The newly designed anode demonstrated exceptional discharge performance. • A guideline for designing novel anodes with high performance was proposed. Reconciling the inherent trade-off between anodic efficiency and discharge voltage in the design of high-energy-density magnesium-air (Mg-air) batteries has been a persistent challenge. Herein, we propose a pioneering active learning strategy that integrates physically motivated variables, machine learning, exploration of the Pareto front, experimental data feedback, and generated data feedback for the purpose of designing magnesium anodes. Within an extensive compositional space (∼350,000 possibilities), we have pinpointed a novel alloy, Mg-1Ga-1Ca-0.5In, exhibiting exceptional performance with high efficiency (64 ± 5.5 % at 1 mA cm−2, 64 ± 0.5 % at 10 mA cm−2) and high voltage (1.80 ± 0.00 V at 1 mA cm−2, 1.57 ± 0.01 V at 10 mA cm−2), surpassing conventional methods of alloying. Subsequent experiments and density functional theory (DFT) calculations have unveiled that the outstanding performance of Mg-1Ga-1Ca-0.5In stems from "grain boundary activation" induced by active second phases and "intra-grain inhibition" resulting from the orbital hybridization between solute atoms and Mg atoms. This study provides a novel research paradigm and offers valuable insights for the further development of high-performance Mg-air batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multi-yolk-shell structure is constructed to disclose the reaction activity of Fe-based compounds toward potassium-ion storage. • FeSe 2 @C shows superior rate capability due to the good electron/K+ conductivity of FeSe 2 and its excellent pseudocapacitive behavior. • The weak electron conductivity of FeS 2 and large K+ diffusion barrier of FeP result in inferior potassium storage performance. Iron-based compounds have been extensively applied as anode materials for alkali-ion batteries. Nevertheless, how the intrinsic properties of Fe-based compounds affect their alkali-ion storage behavior still remain blurry, hampering the rational structure design of Fe-based anodes for superior performance. Herein, the reaction activities of various Fe-based compounds (e.g., FeS 2 , FeSe 2 , and FeP) toward K/Na/Li-ion storage are studied by rationally encapsulating Fe-compounds into hollow carbon boxes with an identical multi-yolk-shell structure. For potassium storage, FeSe 2 @C composite manifests the best battery performance with high capacity, superior rate capability, and excellent cycling behavior. FeS 2 @C exhibits high capacity, but with poor cycling retention and inferior rate capability. FeP@C shows the lowest capacity and poorest rate capability. As disclosed by density functional theory calculation and kinetics analysis, the superior potassium storage behavior of FeSe 2 @C is due to the high electrical conductivity and proper K+ diffusion ability of FeSe 2 , as well as its excellent pseudocapacitive behavior. The weak electron conductivity of FeS 2 is responsible for its poor rate performance, and the large K+ diffusion barrier of FeP leads to its low reaction activity toward potassium-ion storage. Moreover, FeSe 2 @C also displays best rate capability among these Fe-based composites for both sodium and lithium storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • The effect of Au-decorated on NO 2 adsorption on ZnO NW was examined by DFT. • Theoretical mechanism of Au decoration in improving of NO 2 -response was considered. • Dissociation reaction and catalyzer of Au were clarified for NO 2 adsorption on Au. • Selectivity of Au-ZnO NW to NO 2 gas was investigated by Bader charge analysis. The adsorption of NO 2 on a pristine and Au-decorated ZnO nanowire (NW) was investigated using density functional theory (DFT) calculations to determine the role of Au-decoration on the gas sensing response of ZnO NW. Au decoration changed the electronic structure of ZnO NW, which could improve the NO 2 adsorption gas molecules on the surface of Au-decorated ZnO NW. Bader charge analysis showed that the enhanced response of Au-decorated ZnO NW gas sensor to NO 2 gas was related mainly to the gas adsorption on Au atoms. The NO 2 molecule adsorbed on the Au atom captures 0.54 e from the Au-decorated ZnO NW, which is higher than that of the pristine one. Calculations of the charge density difference and geometry revealed the catalytic role of Au for NO 2 adsorption. [ABSTRACT FROM AUTHOR]

The waste cooking oil is upcycled into N-doped carbon nanosheets, enabling fast Na+/K+ storage by means of surface charge modulation. [Display omitted] • Waste cooking oil was selected as precursor to prepare hard carbon anode materials. • NWCOC650 takes on a porous nanosheet structure with turbo layers. • NWCOC650 has a coexistence storage mechanism of adsorption/intercalation-filling. • Head group (–NH 2) can produce a synergistic effect with N-5/6/Q and graphene. • NWCOC650 exhibits excellent performances for sodium/potassium-ion batteries. Hard carbons are significant in sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). However, the structural defects of hard carbons lead to poor rate performance and cycling stability, which need further improvement. The waste cooking oil was used as the precursor to synthesize 3D carbon nanosheets (NWCOC) with amino nitrogen functional groups, multi-layered pores, and expanded interlayer spacing. The excellent electrochemical properties of NWCOC were investigated and it was demonstrated that NWCOC can significantly improve the adsorption of Na+/K+ on hard carbons, substantially enhancing the embedding/de-embedding of Na+/K+, reducing the diffusion distance of ions and electrons, and improving their adaptability to volume changes. In situ XRD and Raman characterization reveal that the Na storage mechanism of NWCOC is mainly based on adsorption/intercalation-filling. Combined with density functional theory, it is shown that the porous structures doped with nitrogen have a greater propensity for ion adsorption, resulting in increased ion capture and storage. As expected, NWCOC650 exhibits high capacities of 489.4 and 388.3 mAh/g in SIBs and PIBs. NWCOC650 displays superior performance in the Na 3 V 2 (PO 4) 3 /NWCOC650 full cell, achieving a capacity of 107.84 mAh/g. This work presents a new perspective on the synthesis and mechanisms of high-performance anodes for SIBs and PIBs. [ABSTRACT FROM AUTHOR]

In this chapter, N and S co-doped mesh porous carbon materials (NSC) were prepared using freeze-drying assisted high-temperature carbonization, where sodium polyacrylate was used as the carbon source and sodium thiosulfate (Na 2 S 2 O 3) and sodium nitrate (NaNO 3) is the sulfur and nitrogen sources, respectively. Its unique layered porosity and the ability to dope sulfur atoms up to 5.9 % allows for the introduction of more defect sites and expanded interlayer spatial interactions, achieving impressive electrochemical properties. Enlightened by the properties of N/S double doping and high pore defects, NSC anodes exhibit a high storage of K+ (441.6 mA h/g at 0.05 A/g) and superior rate performance. The density functional theory (DFT) and electrochemical experimental investigation showed the N/S dual doping can successfully modify the electronic structure and improve the capacity of adsorbing K+. Significantly, the assembled dual-carbon PIHC can deliver an impressive energy density of 141.2 Wh kg−1 at a power density of 400 W kg−1 and a satisfactory cycle life when using the NSC-700 porous carbon as the cathode, which can light the "CUMT" pattern, sheding new light on creating improved carbon materials for using in practical applications. [Display omitted] • N and S co-doped mesh carbon materials were prepared for K-ion hybrid capacitors. • High specific surface area and S-rich carbon is designed with a sulfur content of 5.9 %. • The K+ storage mechanism was deeply studied by electrochemical and DFT calculations. • The dual-doped carbon employed in PIHC exhibits an energy density of 141.2 Wh kg-1. The primary research challenge concerning K-ion batteries revolves around ensuring their optimal cycle stability and specific capacity, particularly the inherent sluggish kinetics induced by the relatively large radius of K+. In this study, we report a pore-size controllable synthetic approach employing salt-template precursors. Herein, nitrogen and sulfur co-doped porous carbon materials with rich carbon defect engineering was synthesized through the salt template method, where the doped heteroatoms can both offer a lot of carbon defect content and redox active sites that are helpful for enhancing potassium ion storage kinetics. As a result, the electrode with abundant doping atom content realizes a good capacity and long cycle lifespan (274.8 mA h g−1 after 200 cycles at 0.05 A/g). Inspiringly, PIHCs assembled by N/S co-doped carbon anode exhibit excellent cycling stability (93.4 % capacity retention for 1000 cycles) and a high energy density of 141.2 Wh kg−1 and a power density of 1.6 kW kg−1. Importantly, the density functional theory calculation combining electrochemical kinetic analysis further demonstrates that role of N and S doping plays dominant roles in total storage mechanism. This work gives a deep insight about the roles of external defects in doping carbon materials for potassium storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reactions of bis(cyclopentadienyl) ruthenium (ruthenocene, RuCp 2) and cyclopentadienyl pyrrolyl ruthenium (RuCpPy) on the hydroxylated surface were explored by density functional theory calculations. • Ru precursors, such as bis(pyrrolyl) ruthenium (RuPy 2), were designed for H 2 O-based atomic layer deposition of RuO 2 · x H 2 O. • New cascade mechanism of H 2 O-based atomic layer deposition of RuO 2 · x H 2 O was proposed. As the unique nanofabrication technique, atomic layer deposition (ALD) can be used to deposit high-quality, uniform, and conformal nanoparticle coatings. Ru and its oxides (RuO x) are important materials in the fields of microelectronics and catalysis. In this work, the reaction of Ru precursors with different ligands on the hydroxylated surfaces were explored. The elimination of the pyrrolyl (Py) ligand is easier than that of the cyclopentadienyl (Py) ligand on the hydroxylated surface. The reaction involved in RuO 2 · x H 2 O ALD using RuPy 2 and H 2 O as precursors was further investigated. During the RuPy 2 reaction, the pyrrolyl ligand is eliminated by the substitution reaction with a surface hydroxyl group. However, the desorption of the pyrrole molecule is difficult due to the strong adsorption between the pyrrole molecule and Ru surface. During the H 2 O reaction, the H 2 O molecules further help the elimination of pyrrolyl ligands from the surface and the dissociative desorption of pyrrole molecules This unique reaction mechanism involved in the ALD of RuO 2 with the assistance of H 2 O can be termed new cascade mechanism. These findings provide theoretical guidance for precursor design and ALD growth of metal oxides. [ABSTRACT FROM AUTHOR]

Rod-like BiVO 4 with monoclinic and tetragonal phase structure are prepared, which constructs p-n junction and forms the build-in electric field at contact interface of two phase, thus boosts the separation and transmission of carriers, at the same time, loading the catalyst on the Ni foam is benefit to enhance holding force. [Display omitted] • Rod-like morphology and two-phase structure BiVO 4 (R-BVO) are successfully prepared. • The two-phase structure of R-BVO forms the p-n junction, boosting the separation of carriers. • Loading the catalyst on the Ni foam is benefit to enhance holding force and recycle. • The electron transfer process of build-in electric field is revealed by DFT calculation. Bismuth vanadate (BiVO 4) as a potential photoanode is widely applied in photoelectrocatalytic (PEC) degradation flied. However, it is inhibited due to easy recombination of the photogenerated carries. Herein, rod-like morphology BiVO 4 with monoclinic and tetragonal phase structure (R-BVO) are prepared using hydrothermal approach. Density functional theory (DFT) calculation confirms that the build-in electron field is constituted at contact interface of two-phase structure. Benefiting from the one-dimensional conduction of rod like morphology and the p-n junction formed by two-phase structure, R-BVO indicates outstanding photocurrent, the applied bias photo-to-current efficiency (ABPE) and the incident photoelectron conversion efficiency (IPCE). Compared with the single phase structure particle BiVO 4 (P-BVO), the PEC degradation rate for TC of R-BVO is 96.4 %, which is 1.4 times of P-BVO. Equally importantly, the Ni foam is used as conducting substrate owing to its low cost and practicability, moreover, it is not only easy to determine catalyst dosage, but also ensures the tight contact between active substance and substrate, preventing the catalyst from peeling off in reaction. This study puts forward an adventurous strategy for designing effective photoanode materials. [ABSTRACT FROM AUTHOR]

Indium selenide (InSe) nanofilms with high carrier mobility and tunable band structure are a typical III-VI group two-dimensional semiconductor material, which has attracted extensive attention in the field of microelectronics and optoelectronic materials. However, due to a large number of interface defects and low efficiency of internal photogenerated charge separation in two-dimensional materials, it is difficult to achieve efficient photoelectric conversion and slow down the carrier decay rate. Here, a two-step magnetron sputtering method was used to synthesize ε-InSe/transition metal dichalcogenides (TMDs) (MX 2 : M = W, Mo; X = Se, S) heterojunctions films. The electronic transitions and exciton relaxation mechanisms in linear and nonlinear absorption of ε-InSe/TMDs heterojunctions films under light excitation were analyzed. The charge transfer and orbital contribution of ε-InSe/TMDs heterojunctions were discussed. The electromagnetic field changes of InSe/TMDs heterojunctions were simulated. The formation of type II InSe/TMDs heterostructures effectively separates photo-generated electrons and holes, increases the lifetime of carriers, and is of great significance for understanding the physical contact behavior between TMDs and TMDs semiconductors and promoting their applications in optoelectronic devices. [Display omitted] • A two-step MS method was used to synthesize ε-InSe/TMDs (MX 2 : M = W, Mo; X = Se, S) heterojunctions. • The electronic transitions and exciton relaxation mechanisms of ε-InSe/TMDs heterojunctions were analyzed. • FDTD and DFT investigated the electromagnetic field changes, charge transfer and orbital contribution of ε-InSe/TMDs. • The effectively separating photo generated electrons and holes and NLA mechanism of samples were analyzed. Indium selenide (InSe) nanofilms with high carrier mobility and tunable band structure have attracted widespread attention in the fields of microelectronics and optoelectronic materials. However, improving the carrier lifetime and enhancing the optoelectronic properties of InSe remain challenging research. Here, designed and prepared type II InSe/transition metal dichalcogenides (TMDs) (MX 2 : M = Mo, W; X = S, Se) heterojunctions films. The (0 0 4) diffraction peak of the 2H phase InSe stacking and the A1 1g (LO) vibration mode generated by the noncentrosymmetric characteristics can be determined as ε-InSe. The charge transfer and orbital contributions between the ε-InSe/TMDs heterojunctions were clarified. Density functional theory calculations indicate that electrons transfer from the In-5s and Se-4p orbitals of ε-InSe to the bottom of the CB of the TMDs films. Finite-difference time-domain simulation confirmed that the charge transfer between ε-InSe and TMDs films enhances their electromagnetic field intensity. By adjusting the incident laser energy in femtosecond Z-scan technology, the reverse saturable absorption properties of ε-InSe/WSe 2 heterojunctions films are enhanced, providing an effective channel for charge transfer. The electron and energy transfer mechanism between InSe and WSe 2 has been revealed, effectively increasing the lifetime of carriers and making it have broad application prospects in the field of semiconductor devices. [ABSTRACT FROM AUTHOR]

The Ni charge state in NiO, modifiable by diverse supports, serves as a key reactivity descriptor for evaluating the OC surfaces. This screening strategy expedites fine-tuning of innovative OC/support combinations for CH4 chemical looping. [Display omitted] • Identify rate-limiting steps in nickel-based oxygen carrier chemical looping. • Compared effects of diverse aluminum-based supports on rate-limiting step. • Elucidated mechanism: Support inhibits sintering, enhances reaction activity. • Explored correlation between kinetics and electronic traits of oxygen carriers. • The scheme for the rational design of support was proposed. Metal oxides play a pivotal role in the conversion of carbonaceous fuels. Nickel-based oxides, due to their affordability and high C–H activation activity, are regarded as promising oxygen carriers (OCs) for CH 4 chemical looping technologies. Additives like Al 2 O 3 , ZrO 2 , and MgAl 2 O 4 are used to boost the reactivity of OCs and mitigate agglomeration of OC particles at elevated temperatures. Despite extensive experimental studies on support selection, the influence of support materials on CH 4 conversion remains unclearly. This research analyzed and compared the kinetic pathways of CH 4 conversion on the supported and unsupported nickel-based OCs, utilizing the Density Functional Theory (DFT) model, to determine the rate limiting step (RLS) in the chemical looping process. The most promising support, NiAl 2 O 4 , weakens the Ni-C bond due to pronounced interaction between the OCs and supports, thereby leading to a reduced activation energy barrier for CH 4 dehydrogenation. By probing the relationships between reaction kinetic barriers and critical electronic properties of OCs, a screening strategy is proposed to accelerate the development and optimization of novel OC/support materials for CH 4 chemical looping conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • We selected the antifouling carbon nanomaterials for PPF monitoring through DFT calculations and experiments. • For the first time, the antifouling ability of different carbon nanomaterials on PPF oxidation products were compared. • The ranking of critical factors for antifouling performance was hydrophilicity > geometric morphology > active surface area. • We propose a mechanism-driven approach to design a highly sensitive and durable biosensor for point-of-care PPF monitoring. Carbon nanomaterials, renowned for their exceptional sensitivity and selectivity towards various medical drugs, hold promise as electrode materials for electrochemical biosensors in propofol (PPF) monitoring. However, the issue of fouling has hindered their effective utilization in continuous point-of-care monitoring. In this research, we present a mechanism-driven approach to design a highly sensitive and durable electrochemical sensor tailored for PPF monitoring. We investigated the antifouling mechanism through density functional theory calculations and experiments and found that carboxyl functional groups contribute to the sensitivity and antifouling properties of the electrode. We have uncovered the antifouling ability of different carbon nanomaterials on PPF oxidation products. Factors such as hydrophilicity, geometric morphology, and active surface area played pivotal roles in antifouling. Furthermore, surface modification with hydrophilic polydopamine further enhanced the antifouling effects. In this study, we extensively investigated the electrochemical oxidation of PPF and its oxidation product on carbon nanomaterials, as well as the antifouling mechanism of carbon nanomaterials. The modified electrodes exhibit excellent antifouling performance and stability. This achievement presents a promising approach towards the development of point-of-care PPF analysis in clinical settings. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesizing multi-metal composite shell materials for the catalytic oxidation of toluene. • Detailed Density Functional Theory (DFT) calculations to determine the adsorption energy. • Revealing the mechanism of toluene oxidation catalyzed by CoNiCu-LDO. Amidst the increasing concerns regarding the emission of volatile organic compounds (VOCs), the pressing task at hand is the development of effective and environmentally benign technologies for catalytic VOC reduction. In the context of this research endeavor, the distinct attributes of zeolite imidazoline framework (ZIF-67), known for its high yield, absence of deleterious by-products, and rapid synthesis, are harnessed. In pursuit of this goal, a series of ZIF-67-derived layered double oxides (LDO) multimetallic composite shell materials for toluene combustion were successfully synthesized: CoNi-LDO and CoNiM-LDO (M = Ce, Cu, Mn and Fe).The experimental results show that due to the uniform dispersion of Co, Ni, and Cu atoms within the CoNiCu-LDO catalyst, the prevalence of oxygen vacancies, a significant specific surface area, and robust interactions among these constituents, a synergistic formation involving O v - Cu2+ - O 2 - Co3+ - O 2 - Ni3+ emerges, the CoNiCu-LDO exhibits an excellent catalytic efficiency. Furthermore, through Density Functional Theory (DFT), the adsorption energies and the projected density of states (PDOS) for toluene, O 2 , H 2 O, and SO 2 on the catalysts have been meticulously computed. Ultimately, the intricate mechanism underpinning the catalytic oxidation of toluene on CoNiCu-LDO has been unveiled through in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). [ABSTRACT FROM AUTHOR]

[Display omitted] • The addition of ammonia solution increased the flotation recovery rate of hemimorphite. • After adding ammonia, more ZnS was formed on the hemimorphite surface. • The presence of H 2 O hinders the adsorption of HS− on the hemimorphite surface. • The adsorption energy of HS− on the hemimorphite surface with ammonia solution is lower than that without ammonia solution. This study investigated the impact of ammonia (NH 3) solution on the flotation behavior of hemimorphite sulfidation, employing a comprehensive analysis that encompasses micro-flotation experiments, X-ray photoelectron spectroscopy (XPS) analysis, contact angle testing, atomic force microscopy (AFM) imaging, and density functional theory (DFT) calculations. The introduction of ammonia water (NH 3 ·H 2 O) resulted in a significant 22.64 % increase in hemimorphite recovery rate, as demonstrated in flotation tests. In this study, both XPS and AFM analyses provided compelling evidence supporting the assertion that NH 3 ·H 2 O facilitated the sulfidation of the mineral surface, resulting in an increased formation of sulfide products. Contact angle testing indicated that surface modification with NH 3 ·H 2 O enhanced the hydrophobic properties of the hemimorphite. DFT calculations offered valuable insights into the effect of NH 3 on the hydration layer, indicating that NH 3 substituted H 2 O molecules and increased the distance between Zinc (Zn) and O5 (H 2 O) to 5.6 Å. Furthermore, the adsorption energy of HS− on the hemimorphite (1 1 0) surface significantly increased with NH 3 enhancement (−18.05 eV) as opposed to without NH 3 enhancement (−12.79 eV). These results indicated that the adsorption configuration of NH 3 in conjunction with HS− was more stable than that of HS− alone on the hemimorphite (1 1 0) surface. Thus, the collective results provided valuable insights into the enhanced sulfidation mechanism activated by ammonium complexation on the hemimorphite surface. [ABSTRACT FROM AUTHOR]

TiO 2 aerogels with high surface oxygen vacancies were fabricated by sol–gel method followed by supercritical drying. Density functional theory revealed that abundant surface oxygen vacancies endow TiO 2 aerogels with high electrostatic potential, which promotes the formation of stable surface charge transfer complexes and allows significant charge transfer from molecules to TiO 2 aerogels. [Display omitted] • TiO 2 aerogels with high surface oxygen vacancies were fabricated. • TiO 2 aerogels showed narrower band gap and higher electron density of states. • TiO 2 aerogels exhibited excellent SERS performance. • Density functional theory further revealed the SERS mechanism. The exploration of new and high-performance semiconductor substrates has always been one of the most important research directions in SERS technology. However, the low sensitivity of semiconductor SERS substrates limits their application. Herein, TiO 2 aerogels with high surface oxygen vacancies were fabricated by sol–gel method followed by supercritical drying. Compared with traditional semiconductor materials, TiO 2 aerogels exhibit low detection limits (1 × 10–7 M) for 4-mercaptobenzoic acid molecules. Moreover, density functional theory further revealed that abundant surface oxygen vacancies endow TiO 2 aerogels with high electrostatic potential, which promotes the formation of stable surface charge transfer complexes and allows significant charge transfer from molecules to TiO 2 aerogels. It is worth noting that the narrower band gap and higher electron density of states of TiO 2 aerogels effectively enhance the vibrational coupling in the substrate-molecule system, leading to significant SERS activity of TiO 2 aerogels. [ABSTRACT FROM AUTHOR]

[Display omitted] • The orientation-dependent growth mechanism of Cr-rich oxide precipitate is revealed. • The directed growth is thermodynamically preferred than the isotropic growth. • The outward diffusion of Fe atom leaving vacancies which enhancing the Cr diffusion. • O promotes the aggregation of Cr atoms along the [1 0 0] direction. Advanced characterization techniques and atomic simulations, including density functional theory calculation and molecular dynamics simulation, are performed to reveal the orientation-dependent growth mechanism of Cr-rich oxide precipitates in the internal oxide layer of Fe-9Cr steel under supercritical water environment. A new Fe/Cr/O/H reactive force field is constructed to address the limitations of existing empirical potentials in accurately describing the corrosion mechanism of FeCr alloy. The high-resolution characterization reveals the growth mechanism of needle-like FeCr 2 O 4 precipitates in the <1 0 0> direction of the matrix. Atomic simulation demonstrate that the directed growth is thermodynamically preferred than the isotropic growth. The vacancies generated by the outward diffusion of metal atoms enhancing the diffusion of Cr atoms, and O promote the aggregation of Cr atoms along the <1 0 0> direction. [ABSTRACT FROM AUTHOR]

[Display omitted] • B-N doped biphenylene are electronically and dynamically stable with metallic or semiconducting characteristics. • Uniaxial lattice strain engineering is an effective approach to activating inert BPN and BCN-BPNs toward HER. • The best overpotential for HER is achieved to be 0.011 V by finely tuned strain. • HER activities were determined not only by the active sites but also by the surrounding microenvironment. The exploration of novel metal-free electrocatalysts with excellent activity and stability is important for scaling up hydrogen production via water splitting. Herein, we report a series of novel two-dimensional networks obtained by doping biphenylene (BPN) with B-N pairs, referred to as BCN-BPNs. Density functional theory calculations indicate that the designed BCN-BPNs are electronically and dynamically stable with metallic or semiconducting characteristics. It is further revealed that uniaxial lattice strain engineering is an effective approach to activating inert BPN and BCN-BPNs toward the hydrogen evolution reaction (HER). The best overpotential for HER is predicted to be 0.011 V, achieved by finely tuning strain. A machine learning model with an extreme gradient boosting regressor and a polynomial feature approach was successfully built to predict HER activities. The model achieved mean absolute errors and root mean squared errors of 0.068 and 0.261, respectively. Feature importance analysis highlights the role of both active sites and their microenvironment in determining HER activities. Our study suggests a series of novel metal-free BCN-BPNs with considerable potential for HER. Additionally, a predictive strategy is proposed for fast screening, which would benefit the development of HER catalysts that exhibit both cost-effectiveness and superior performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • The adsorption of carbon deposition species (C1 ∼ C11) was investigated to discuss the most stable adsorption configurations and possible configurations transformations. • The reactions of carbon deposition on the surface of NiFe catalyst were studied to analyze the possible reaction paths and explore the carbon growth process. • The effect of temperature on the carbon deposition process was researched. • The main growth path and growth law of carbon species were clarified. • The anti-carbon deposition performance of the catalyst can be improved by increasing the activation energy of carbon–carbon coupling and inhibiting the formation of C2. Carbon deposition often occurs in CO methanation on NiFe catalyst, resulting in the deactivation of the catalyst, which is an urgent problem to be solved in industrial production. In this work, the carbon deposition process on the surface of NiFe catalyst was systematically investigated by the combination of Density Functional Theory (DFT) and Kinetic Monte Carlo (KMC). The results of DFT calculations show that for C1 ∼ C9, the most stable adsorption configurations are carbon chains while for C10 and C11, the carbon rings are the most stable. Besides, in the reaction network of carbon deposition, the formation of C2 is the key reaction with high activation energy. KMC simulation shows that temperature can significantly affect the occurrence of carbon deposition and C2 will accumulate and react to form larger carbon species instead of decomposing. In addition, the growth rate of carbon chains is faster than that of carbon rings, and carbon species mainly react with C1 and C2 to form longer carbon chains. Therefore, the anti-carbon deposition performance of the catalyst can be improved by increasing the activation energy of carbon–carbon coupling and inhibiting the formation of C2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mo atom anchored on non-metallic regulated graphene for water splitting is studied. • Mo@X 4 C (X = B, P, S, N) are low cost and stable catalysis systems. • Adsorption ability of H 2 O on Mo@X 4 C are related to d-band centers of Mo. • The relationship between Bader charge, work function and HER were explored. • The Mo@B 4 C is recommended as superior catalyst for water splitting and hydrogen production. High efficiency electrocatalysts play a crucial role for clean and green hydrogen energy. Here, the catalytic performance of Mo atom anchored on graphene surfaces regulated by non-metal (X = B, P, S, N) for water splitting and hydrogen evolution reactions (HER) is investigated by the first principles of density functional theory (DFT). The structural and electronical properties calculation demonstrated that the stable Mo@X 4 C systems can be created where covalent bond is formed between Mo and X atoms. It is also found that the adsorption ability of H 2 O on Mo@X 4 C (X = B, P, S, N) surfaces are directly related to d-band centers of Mo atoms. In water splitting process, the splitting reaction energy barrier of H 2 O has the trend of Mo@B 4 C < Mo@P 4 C < Mo@S 4 C < Mo@N 4 C. Significant orbital hybridization coupling and charge transfer occur between adsorbed H 2 O molecule and Mo@X 4 C surfaces. Specifically, the Mo@B 4 C catalyst is predicted to exhibit not only promising splitting activity, but also superior high performance for HER. And the value of Δ G H* is 0.04 eV, which is very close to ideal zero. Thus, it can be recommended as a stable, low-cost and superior performance catalyst for hydrogen production. Lower Bader charge of Mo and larger work function both facilitate the release of hydrogen. It reveals that non-metallic coordination regulation serves as promising way to design high performance electrocatalysts for water splitting and hydrogen production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Among the studied molecules, those with larger π–networks have greater adsorption energies at the Fe (110) surface, thus better corrosion protection efficiency. • π–back donation is found to be the dominant adsorption mechanism for the adsorption process of the studied molecules on Fe(110). • Finding highly negative adsorption energies for the molecules with π–networks in both vacuum and aggressive solutions indicates that they are potential candidates for corrosion protection of Fe. Wise selection and application of a green corrosion inhibitor requires a careful study of its adsorption mechanism at the metal surface. Herein, density functional theory calculations were carried out to investigate the adsorption behavior of six green corrosion inhibitor molecules on Fe(110) surface, i.e. serotonin, tyrosine, coumaric acid, histamine, vanillic acid, and lysine. Different adsorption configurations through the functional groups and aromatic rings were carefully examined for each molecule. The projected density of states, Bader charge values, charge density difference, and the ELF analysis were calculated For the energetically preferred adsorption configurations. Ab–initio molecular dynamics simulations were also performed to obtain the equilibrium structure for the adsorption of the molecules on the Fe(110) at 300 K in an acidic solution. The analyses reveal the critical role of π–d interactions, in the form of π–back donation, in determining the preferred adsorption configuration of the inhibitor molecules on the Fe(110). The adsorption energies were found to be in the range of −154.376 kJ/mol for lysine to −371.275 kJ/mol for coumaric acid. The adsorption energy data reveals that the molecules with larger π–networks have greater adsorption energies at the Fe (110) surface, and thus better corrosion protection efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • In 2 O 3 and SnO 2 form an n-n heterojunction, which improves the gas-sensitive properties of SnO 2. • In 2 O 3 grows in situ on SnO 2 , and the composite has a unique hedgehog-like nanoflower morphology with abundant oxygen vacancies. • Improved gas-sensitizing properties attributed to the change in charge density. • Formation of heterojunction leads to In 2 O 3 -SnO 2 composites with higher electron transfer capacity and accelerated charge transfer kinetics. The In 2 O 3 -SnO 2 heterojunction nanostructures resembling hedgehogs were synthesized through hydrothermal method and physical stirring for acetone detection. SEM and TEM characterization showed that the composites were SnO 2 nanosheets (NSs) assembled into a flower-like morphology with In 2 O 3 particles grown in situ on the NSs. The In 2 O 3 -SnO 2 sensor has excellent vapor sensitivity compared to pure SnO 2. At an optimal temperature of 260 ℃, the In 2 O 3 -SnO 2 sensor achieves a response value of 19.4 for acetone vapors at a concentration of 100 ppm. The composites still exhibit excellent gas-sensitized performance at low concentration (100 ppb). The improved gas-sensitized performance of In 2 O 3 -SnO 2 composites is attributed to the sea urchin-like nanoflower morphology enriched with oxygen vacancies and the formation of n-n heterojunctions. To further substantiate its enhancing mechanism, the adsorption behavior of acetone molecules on the fabricated composite material was investigated through the utilization of density functional theory (DFT). This study confirms the enhanced gas sensing performance of In 2 O 3 -SnO 2 heterojunction composites towards acetone and elucidates the enhancement mechanism by DFT calculations. [ABSTRACT FROM AUTHOR]

[Display omitted] • S-scheme Bi 12 TiO 20 /Bi 4 Ti 3 O 12 heterojunction was in-situ growth on a 3D-printed SiOC structure to form monolithic photocatalysts. • 3D-printed structure enhances light utilization and mass transport. • The S-scheme heterojunction improves the photogenerated carrier separation efficiency and redox ability of the material. • Bi 12 TiO 20 /Bi 4 Ti 3 O 12 /SiOC exhibit superior reusability and stability. • Detailed photocatalytic mechanisms and reaction pathways were proposed. Photocatalysis is recognized as one of the most promising techniques for environment purification. However, the inconvenient recovery of powder photocatalysts significantly impeded their practical applications. Immobilization of the photocatalysts on supports to form monolithic photocatalysts is an effective method to solve this problem. Herein, a monolithic photocatalyst Bi 12 TiO 20 /Bi 4 Ti 3 O 12 /SiOC is fabricated by growing optimal Bi 12 TiO 20 /Bi 4 Ti 3 O 12 S-scheme heterojunction onto 3D-printed porous SiOC support. On one side, S-scheme heterojunction facilitates the separation of photoinduced electrons and holes while retaining their strong redox ability. On the other side, the porous structure favors mass transport and improves light harvesting by reflecting the light several times. Under simulated solar light irradiation, the NO removal efficiency of the monolithic photocatalyst Bi 12 TiO 20 /Bi 4 Ti 3 O 12 /SiOC is 16.4 %. Furthermore, the composite has good stability and reusability, suggesting its great potential in practical application. The possible photocatalytic mechanism is proposed according to systematic experiments and density functional theory (DFT). This work provides a rational reference for constructing efficient photocatalysts for environmental purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combination of experiments and DFT calculations. • Triazole derivatives are eco-friendly and sustainable inhibitors for metal. • Effect of various derivative groups on inhibition efficiency. • Multi-angle study of molecular activity and adsorption behavior on Cu surface. • Provide reference for the selection of organic inhibitors for multiple metals. The impact of triazole derivative groups on corrosion inhibition performance of copper (Cu) film is studied by using 3-amino-1,2,4-triazole-5-carboxylicacid (ATA-O), 1H-1,2,4-triazole-3,5-diamine (ATA-N) and 3-amino-5-mercapto-1,2,4-triazole (ATA-S) as environment-friendly inhibitors. Electrochemical analysis showed that anti-corrosion passivation layer is formed on Cu surface after adding inhibitors with high inhibition efficiency of 54 %, 87 % and 98 % respectively, and improve the surface quality which is verified by atomic force microscope (AFM) and scanning electron microscopy (SEM) tests. Such results are consisted with static etch experiments. The mechanism of corrosion inhibition was revealed by theoretical calculation, which prove that the lone electron pair in empty orbitals of the O, N, S atoms on inhibitors hybridize with the Cu-d orbital to form covalent bonds and enhance the adsorption passivation action. Such study dissects the reasons for the potent inhibitory effect of triazole derivatives at the atomic level, and provides new method for efficient selection of inhibitors. [ABSTRACT FROM AUTHOR]

[Display omitted] • The hollow porous carbon was designed and prepared by cattail leaves. • A ZIHSs charge storage mechanism for C = O and pyrrolic-N was investigated. • For ZIHSs, CLHPC exhibited an excellent energy density of 128 Wh kg−1. • Impressive specific capacitance and ultra-long life have been attained. The development of high-energy–density advanced Zinc-ion hybrid supercapacitors (ZIHSs) shows significant potential, yet it remains a complex undertaking due to its heavy reliance on physical Zn2+ adsorption and the limitations imposed by insufficient cathodes. This study employs a rich in C = O and pyrrolic-N functional groups hollow porous carbon derived from cattail leaves as a cathode material for high-energy-power ZIHSs. The proposed charge storage mechanism involves the assimilation of opposite charge carriers, coupled with a multi-electron redox response, which was investigated by Ex-situ experiments and density functional theory (DFT) simulations. This process entails the alternating binding of Zn2+ and SO 4 2− at designated active sites, along with strong relationships between Zn2+ and electronegative C = O/pyrrolic-N motifs, leading to the creation of C-O-Zn-N-C bonds. Consequently, the aqueous ZIHSs constructed with this hollow porous carbon cathode exhibit outstanding performance metrics. These include an impressive energy density of 128 Wh kg−1, a discharge specific capacity of 149 mAh/g at 10 A/g, a superb power density of 1188 W kg−1, and an extraordinary long-term lifespan, retaining 95 % of its initial capacity after 10,000 cycles. Importantly, the strategy of augmenting energy storage through chemical adsorption capability modulation can be applied to other carbon materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The HOR activity of RuN 2 monolayers can be finely tuned by 3d TM doping. • The ortho -N and metal atoms in TM-RuN 2 form a dual-active site for HOR. • Fe-RuN 2 shows strong stability, good conductivity, and excellent HOR activity. • The high activity of Fe-RuN 2 is due to a well-balanced H* and OH* adsorption. The development of alkaline exchange membrane fuel cells (AEMFCs) is severely hampered by the scarcity of efficient Pt-free catalysts for the anodic hydrogen oxidation reaction (HOR). In this work, we systematically explored the HOR performance of single 3d transition metal atom-doped RuN 2 monolayers (TM-RuN 2 , TM = Ti-Zn) by density functional theory calculations. Formation energy, oxidation potential, and electronic structure analyses indicate that the Ti, V, Fe, Co, and Ni-doped RuN 2 not only have a good conductivity, but also possess strong thermodynamic and electrochemical stability. For TM-RuN 2 , the ortho -N and metal (TM or ortho -Ru) atoms form a dual-active site for the adsorption of H* and OH*, respectively, where the adsorption strength is fine-tunable via the TM-modulated electronic structure. The HOR occurs preferentially through the H 2 + OH*-H* + OH* mechanism on the pristine and Co, Ni, Cu, and Zn-doped RuN 2 , and the Tafel − H* + OH* mechanism on the Ti, V, Cr, Mn, and Fe-doped RuN 2. The precisely balanced H* and OH* adsorption strength of Fe-RuN 2 results in the ultra-low free energy barriers to HOR. Benefiting from the strong thermodynamic and electrochemical stability, good conductivity, and excellent HOR activity, Fe-RuN 2 exhibits a huge potential as HOR electrocatalysts for AEMFCs. [ABSTRACT FROM AUTHOR]

The ORR performances and mechanism of penta -M 2 N 4 have been systematically investigated by density functional theory calculations. [Display omitted] • The dynamical and thermal stabilities of ten novel penta -M 2 N 4 are confirmed by density functional theory. • For the 4e− ORR, p -Rh 2 N 4 (Rh site), p -NiRhN 4 (Ni site), and p -PdRhN 4 (Rh site) are identified as excellent candidates for ORR. • The p- NiPdN 4 (Ni site) and p- PdRhN 4 (Pd site) show outstanding catalytic activity for the 2e− ORR process. • The ORR performances of penta -M 2 N 4 originate from the proper d-band center, and the interaction between the metal active center and the O atom. The excellent oxygen reduction reaction (ORR) activity of the nitrogen-coordinated metal site (the "MN 4 " site) makes them promising candidates. Hence, extending a similar family is of great importance for the development of the ORR catalysts. In this work, we investigate ten penta -M 2 N 4 (M = Ni, Pd, Pt, or Rh) by considering their stability, activity, and selectivity for the ORR performance based on first-principles calculations. Our results show that all the penta -M 2 N 4 (p -M 2 N 4) are dynamically and thermally stable and are promising for synthesis and application in the ORR. The 2e− ORR process overpotentials of p- NiPdN 4 (Ni site) and p- PdRhN 4 (Pd site) are estimated to be 0.07 V and 0.14 V, respectively, showing comparable activities to the well-known CoN 4 -C. For the 4e− ORR, p -Rh 2 N 4 (Rh site), p -NiRhN 4 (Ni site), and p -PdRhN 4 (Rh site) are identified as candidates with excellent ORR performance. Moreover, a structure–activity relationship between the electronic properties and the catalytic performance is established, and the orbital hybridization induced by alloying plays a crucial role in modulating the selectivity in ORR. Our study provides valuable insights for the design of ORR catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The etching reaction of silicon nitride by HF was simulated using DFT calculations. • An amorphous silicon nitride slab model with 25 at.% hydrogen was used. • The cleavage of Si–N or Si–Si showed low activation energies of less than 0.90 eV. • Etching would be plausible through the release of NH 3 , SiF 4 , SiHF 3 , and SiH 2 F 2. • The (NH 4) 2 SiF 6 salt would be formed due to low activation energies of less than 0.40 eV. We report the etching mechanism of amorphous hydrogenated silicon nitride by hydrogen fluoride (HF) gas using density functional theory (DFT) calculations. Since silicon nitride films are deposited as amorphous with a significant amount of hydrogen, we constructed an amorphous substrate model with a hydrogen concentration of 25 at.% using molecular dynamics simulation and DFT calculations. We then created slab models with different degrees of fluorination and simulated all possible fluorination pathways. The pathways involving cleavage of Si–N or Si–Si bonds showed low activation energies of 0.90 eV or lower, while the pathways involving cleavage of a Si–H bond showed high activation energies of 1.54 eV or higher. NH 3 , SiF 4 , SiH 2 F 2 , and SiHF 3 were released with low activation energies, indicating that etching would be favorable. Next, we modeled the formation and desorption of the (NH 4) 2 SiF 6 salt on the fluorinated surface. The salt formation was exothermic with low activation energies, consistent with self-limited etching at low temperatures. At temperatures of 152 °C or higher, (NH 4) 2 SiF 6 would desorb, leaving no solid residue, consistent with the high etch rate at elevated temperatures. Our DFT calculations using the amorphous hydrogenated slab model successfully explained the silicon nitride etching process, which could not be explained by a crystalline Si 3 N 4 slab model. [ABSTRACT FROM AUTHOR]

[Display omitted] • ► Co replaces Fe in pyrite through lattice substitution to form Co-pyrite. • ► Co doping enhances the surface hydrophobicity of pyrite. • ► The electron transfer between BX and Co-doped pyrite is more intense. • ► BX mainly interacts with the Co 3d orbitals of Co-doped pyrite through the S 3p orbitals. • ► BX exhibits more stable adsorption on the surface of Co-doped pyrite than on pyrite. Cobalt (Co), as a vital strategic resource, is applied widely in battery materials and alloy manufacturing. In minerals, Co is often doped into pyrite by lattice substitution. Co-doped pyrite is typically enriched by froth flotation. However, research on the flotation mechanisms of Co-doped pyrite is limited. Density functional theory was used to investigate the influence of Co doping on the crystal structure of pyrite. The difference in the hydrophobicity and collector adsorption of Co doping in pyrite was discussed. Co replaces Fe in pyrite through lattice substitution to form Co-pyrite. Co-doped pyrite shows increased conductivity and decreased covalent bonding nature of Co-S bonds compared with pyrite. Co doping enhances the surface hydrophobicity of pyrite. The electron transfer between butyl xanthate (BX) and Co-doped pyrite is more intense than that of pyrite. BX mainly interacts with the Co 3d orbitals of Co-doped pyrite through the S 3p orbitals. The interaction mode is bonding, and orbital hybridization occurs. Moreover, BX exhibits more stable adsorption on the surface of Co-doped pyrite than that on pyrite. The presence of water molecules has a minor promotional effect on the adsorption of BX. [ABSTRACT FROM AUTHOR]

[Display omitted] • An Au honeycomb patterned template (HPT) used as a substrate of monolayer (1L) TMD. • Raman spectroscopy of 1L WSe 2 showed negligible change at strains below 0.2 %. • At strains below 0.2 %, the PL property of 1L WSe 2 is sensitively changed. • The integrated PL intensity and FWHM of 1L WSe 2 are highly sensitive to low strain. • Density functional theory calculations verify the strain-sensitive PL property. As representative layered quantum materials, monolayer (1L) transition metal dichalcogenides (TMDs) have optical and electronic properties that can be controlled by crystal strain, allowing expanded applications using strain engineering. Raman and Photoluminescence (PL) spectroscopy are the most widely used analytical tools for studying strain in 1L TMDs. Although studies have been reported on strain engineering of 1L TMDs, only results with strain greater than 0.2 % have been reported. To precisely control the strain of 1L TMDs and expand their applications, it is necessary to systematically study the changes in optical properties at low strain. This work investigated the optical property, which changes sensitively at low strains below 0.2 % of 1L TMD, using an Au honeycomb pattern template (HPT). 1L WSe 2 grown by chemical vapor deposition was transferred to an Au HPT, and the strain-induced changes in optical properties were evaluated using confocal Raman and PL spectroscopy. Interestingly, Raman scattering, known to be sensitive to strain, was not changed at strains of less than 0.2 %, while the PL properties were sensitively changed at low strains in 1L WSe 2. The PL properties of 1L WSe 2 , sensitive to strain as low as 0.2 %, have been theoretically verified by density functional theory calculations. [ABSTRACT FROM AUTHOR]

[Display omitted] • 91.38% NO was removed at 175 ℃ via Fenton-like enhanced SCR reactions over FeV 1.31 O x. • The H 2 O 2 and NH 3 adsorpted over Fe 2 V 4 O 13 and FeVO 4 was evaluated via DFT methods. • The Fenton-like enhanced SCR reactions can be enhanced via modulating Fe-V oxides. Low-temperature NO removal technology was critical for tail gas purification. Our previous work has proposed an efficient Fenton-like enhanced SCR reaction over monoclinic FeVO 4. This work modulates the V to Fe ratio (V/Fe) in Fe-V oxides to enhance the NO removal activity. The textual characterization and NO removal of FeV 0.82 O x , FeV 1.31 O x , FeV 1.52 O x, and FeV 1.96 O x were carried out to investigate the structure–activity relationships. For the Fenton-like enhanced SCR reactions, the NO removal efficiency was affected by catalysts with different V/Fe. Based on XPS, NH 3 -TPD, and •OH annihilation tests, it could be deduced that the NO removal in Fenton-like enhanced SCR reactions was simultaneously affected by the performance of SCR reactions and Fenton-like reactions. The density functional theory calculation indicated that the H 2 O 2 was more likely adsorbed on Fe sites of Fe 2 V 4 O 13 , and the adsorption of NH 3 was conducive to the oxidized V sites of FeVO 4. The research elucidated the modulation strategy for NO removal via Fenton-like enhanced SCR reactions over Fe-V oxides. [ABSTRACT FROM AUTHOR]

Bi 2 MoO 6 /ZIF-67 S-scheme heterojunctions with core-shell structures and excellent photocatalytic antifouling performances were fabricated via in-situ enwrapping ZIF-67 nanocubes on Bi 2 MoO 6 flower-like microspheres. [Display omitted] • Novel Bi 2 MoO 6 /ZIF-67 S-scheme heterostructures were synthesized by an in-situ growth method. • ZIF-67 nanocubes were enwrapped on Bi 2 MoO 6 flower-like microspheres to form a core–shell structure. • Bi 2 MoO 6 /ZIF-67 exhibited a highly enhanced visible-light photocatalytic antifouling activity. • The formation of S-scheme heterostructure led to efficient separation of photoinduced charge carriers. • A attempt was made by adding Bi 2 MoO 6 /ZIF-67 into dacromet used marine environment. In this work, novel Bi 2 MoO 6 /ZIF-67 S-scheme heterojunctions with core-shell structures were fabricated via in-situ enwrapping ZIF-67 nanocubes on Bi 2 MoO 6 flower-like microspheres, which were applied in photocatalytic antifouling towards typical marine bacteria and microalgae. Experimental results indicated that Bi 2 MoO 6 /ZIF-67 displayed excellent and stable photocatalytic performances against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) under visible light irradiation, and almost all S. aureus and E. coli can be killed within 40 min and 50 min, respectively. Similarly, Bi 2 MoO 6 /ZIF-67 exhibited remarkable photocatalytic properties in removing microalgae, achieving the removal efficiencies of 96.0% and 84.4% towards Phaeodactylum tricornutum (P. tricornutum) and Chlorella sp. within 6 h, respectively. The introduction of ZIF-67 obviously improved the specific surface area and photoabsorption ability of Bi 2 MoO 6 , combined with the formation of S-scheme heterojunction with core-shell structure, highly enhancing the photocatalytic antifouling activity of Bi 2 MoO 6 /ZIF-67. Moreover, a possible photocatalytic mechanism was proposed, validating that h+, OH, O 2 –, and 1O 2 played crucial roles during the photocatalytic process. The transfer direction of photoelectrons and band structures in Bi 2 MoO 6 /ZIF-67 were further verified by the density functional theory (DFT) simulated calculations, confirming the formation of S-scheme heterojunction and fast separation efficiency of photoinduced charge carriers. Furthermore, Bi 2 MoO 6 /ZIF-67 S-scheme heterojunctions were coated on dacromet and placed in actual marine environment, showing a favorable antifouling performance with fewer living microorganisms attached. This work not only provides new insights in developing novel heterojunctions with highly efficient photocatalytic activities, but also presents a promising application prospect for photocatalysts in the field of marine antifouling. [ABSTRACT FROM AUTHOR]

An S-scheme BiOCl/ZnCrZr-layered bimetallic oxide (BiOCl/ZnCrZr-LBMO) heterojunction was constructed with high photocatalytic degradation activity and applied for efficient removal of bisphenol A. [Display omitted] • S-scheme BiOCl/ZnCrZr-LBMO heterojunction was successfully constructed. • BiOCl/ZnCrZr-LBMO degraded 90.1 % of bisphenol A within60 min. • The photocatalytic degradation mechanism of BiOCl/ZnCrZr-LBMO towards BPA was proposed. • The degradation intermediates were analyzed, and the possible degradation pathways of BPA were proposed. Constructing heterogeneous photocatalysts to enhance the visible light absorption and photo-generated charge carrier separation for efficient degradation of organic pollutants in water samples remained a significant challenge. An S-scheme BiOCl/ZnCrZr-layered bimetallic oxide (LBMO) heterojunction was constructed by depositing BiOCl nanoparticles on ZnCrZr-LBMO. The characterization of material samples were by XRD, SEM, TEM, XPS, FTIR, UV–Vis-DRS, transient photocurrent response, and electrochemical impedance spectroscopy. The photocatalytic efficiency of BiOCl/ZnCrZr-LBMO heterojunction was obviously improved, about 3.95 and 1.68 folds higher than that of pristine BiOCl and ZnCrZr-LBMO, respectively. The fast separation and migration and the prolonged lifetime of photo-generated carriers in the BiOCl/ZnCrZr-LBMO heterojunction were validated by photoelectrochemical tests. The influence factors, versatility, and reusability of the heterojunction were also evaluated. Free radical scavenging test and ESR experiment revealed that ·O 2 – and h+ active radicals were the dominant active radicals in the BPA degradation. Additionally, BPA degradation intermediates were detected by LC-MS, and the possible degradation pathway of BPA was deduced using density functional theory. This novel S-scheme model heterojunction was expected to provide new ideas for the study of the photocatalytic mechanism and the BPA removal. [ABSTRACT FROM AUTHOR]

Implantation of P heteroatom sites into the framework of g-C 3 N 4 can reduce the band gap energy, regulate the electronic structure and effectively adsorb and activate N 2 molecules, thus promoting the visible-light-driven photocatalytic N 2 fixation performance. [Display omitted] • Porous P-doped g-C 3 N 4 nanosheets were synthesized by a one-step calcination method. • DFT calculations revealed the adsorption and activation of N 2 molecules at P doping sites. • PCN0.6 exhibits a highly efficient visible-light photocatalytic N 2 fixation performance. • The charge-transfer and active-site structure diagram for solar N 2 fixation is elucidated. Solar N 2 fixation is a green and pollution-free technology to realize solar energy to chemical energy. Here, P doped g-C 3 N 4 nanosheets (PCN x) with porous structure has been fabricated via a one-step calcination process for efficient ammonia generation. The optimal PCN0.6 catalyst provided an improved visible light photo-performance with an ammonia generation rate of 3110 µg L−1h−1g−1, 15 times higher than that for pristine g-C 3 N 4 (CN). And the quantum efficiency at 400 nm monochromatic light reached 3.29%. Characterization results revealed that the implantation of P−N bonds in g-C 3 N 4 resulted in expanded optical response, larger accessible active sites and efficient separation of electron-hole pairs than that of bulk counterpart. Wavefunction contour maps revealed a more localized charge density distribution upon P doping, leading to a favorable electron-rich structure. The calculated N 2 adsorption energy and N 2 -TPD tests showed the strong capacity of nitrogen chem-adsorption by PCN0.6. Charge density differences and Bader charge demonstrated the electrons transfer from the P doping sites of g-C 3 N 4 to adsorbed N 2 , thus activating N 2 molecules for effective NH 4 + generation. This work offered significant insights into the heteroatom doping engineering to construct active sites and steer the charge migration pathways in g-C 3 N 4 for efficient photo-reduction of N 2. [ABSTRACT FROM AUTHOR]

Density functional theory is used to investigate the electronic properties, diffusion barrier and quantum capacitance of Li, Na, K adsorption on Sc 2 CCl 2 and Sc 2 CF 2 monolayers. The adsorptions of Li/Na/K on Sc 2 CCl 2 and Sc 2 CCF 2 induce the semiconductor–metal transition. Na-Sc 2 CF 2 and Li-Sc 2 CF 2 are anode materials for Na-ion and Li-ion batteries due to higher C M , low OCV and diffusion barriers. [Display omitted] • Li/Na/K adsorption results in the metallic character of Sc 2 CCl 2 and Sc 2 CF 2. • Na-Sc 2 CF 2 and Li-Sc 2 CF 2 are more suitable as anode materials for NIBs and LIBs. • The OCV for Li/Na/K adsorption on Sc 2 CCl 2 is larger than that for Li/Na/K adsorption on Sc 2 CF 2. MXenes have emerged as promising candidate for energy storage devices because of their superior properties. In this work, the electronic properties, low open circuit voltage (OCV) and diffusion barrier of Li, Na, K adsorption on Sc 2 CCl 2 and Sc 2 CF 2 monolayers are investigated by density functional theory. The most stable adsorption site is confirmed because of the shortest adsorption height and largest adsorption energy. The adsorptions of Li/Na/K on Sc 2 CCl 2 and Sc 2 CCF 2 induce the semiconductor–metal transition. Na-Sc 2 CF 2 and Li-Sc 2 CF 2 have higher theoretical capacity (C M), low open circuit voltage (OCV) and diffusion barriers, so they are more suitable as anode materials for Na-ion and Li-ion batteries. The analysis of charge transfer indicates that the adsorbed atoms in Sc 2 CF 2 monolayer lose more electrons than the adsorbed atoms in Sc 2 CCl 2 system because of stronger electronegativity of F. [ABSTRACT FROM AUTHOR]

[Display omitted] • Six novel carbon-based pentagonal structures are investigated for revealing their potential values in Li-S batteries. • The penta-G, penta-C 2 P and penta-C 2 Si have excellent kinetic and thermodynamic stability, anchoring and charge–discharge performances. • These penta furrow structures can reduce the cathode volume change, and enhance sulfur loading capacity. • C–S bonds are the critical factor of capturing LiPSs and reducing the energy barrier of Li 2 S dissociation. The commercialization process of lithium-sulfur batteries (LISBs) is hindered by several problems, including low electroconductivity, the dissolution of lithium polysulfides (LiPSs) and sluggish charging-discharging kinetics. Recently, two-dimensional (2D) penta-furrow structures have emerged as a distinct family of 2D structures with low mass densities, which are predicted to accelerate redox kinetics and enable sulfur conversion. Here, several novel pentagonal carbon-based substrates, including penta-graphene (penta-G) and penta-B 2 C (C 2 N, C 2 P, C 2 Si, and N 2 C), were first investigated in LISBs based on density functional theory (DFT) calculations. It is found that the penta-G, penta-C 2 P and penta-C 2 Si have excellent anchoring ability and can greatly improve conductivity during the whole S 8 /LiPSs insertion, which can effectively suppress the shuttle effect. More importantly, penta-G, penta-C 2 P and penta-C 2 Si can reduce the free energy of sulfur reduction reactions to 0.63–0.68 eV and lower the energy barriers of electrochemical conversions to 0.82–1.57 eV (Li 2 S dissociation) and 0.05–0.14 eV (Li-ion diffusion), thereby enhancing catalytic conversion efficiency in the discharging/charging processes. In addition, penta-G showed a much smaller volume expansion (34 %) than the 80 % value for elemental sulfur and a considerable sulfur loading amount (53.78 wt%). Our findings demonstrate that metallic pentagonal carbon-based materials could be a potential LISBs cathode material with high performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu-Mn-Ni-Zn HEA catalysts were studied as CO 2 RR to CH 4 and CH 3 OH via DFT and ML. • The HEA catalyst candidates are benchmarked to Cu (1 1 1) • Active catalysts were screened via *CO 2 , *CO, *COOH, and *H adsorptions. • Selective catalysts were screened via *COH, *CH 4 , *CHO, and *CH 3 OH adsorptions. • 90% of active sites on Cu-Mn-Ni-Zn catalysts suppress hydrogen evolution reaction. High-entropy-alloy (HEA) catalysts have been used in many challenging electrocatalytic reactions, e.g., CO 2 reduction reaction (CO 2 RR) due to their promising properties. For CO 2 RR catalysts, tuning metal compositions in Cu-based catalysts is one of the techniques to control the desired products. Thus, this work investigated the optimal composition of Cu-Mn-Ni-Zn HEA catalysts using high-throughput screening (HTS) for CO 2 RR targeting on two competing routes toward CH 4 and CH 3 OH products. The screening protocol evaluates catalytic activity through adsorption energy (E ads) of *CO 2 , *CO, *COOH, and *H. At the same time, the selectivity is represented by E ads of *COH, *CH 4 , *CHO, and *CH 3 OH, using density functional theory (DFT) accelerated by machine learning techniques. The screening result from 11,920 data revealed 259 candidates for CH 4 -selective and 4,214 for CH 3 OH-selective catalysts. Interestingly, the Cu-Mn-Ni-Zn excellently prevented competitive hydrogen evolution reaction by up to 90%. Optimal composition for each route are Cu 0.1 Mn 0.4 Ni 0.2 Zn 0.3 and Cu 0.2 Mn 0.4 Ni 0.1 Zn 0.3 in CH 4 -selective route and Cu 0.3 Mn 0.3 Ni 0.2 Zn 0.2 , Cu 0.3 Mn 0.2 Ni 0.3 Zn 0.2 , Cu 0.3 Mn 0.2 Ni 0.2 Zn 0.3 , and Cu 0.2 Mn 0.3 Ni 0.3 Zn 0.2 in CH 3 OH-selective route. The optimal catalyst structure with high CO 2 RR activity in both routes was revealed to have the Mn atom as an active site, while Cu, Ni, and Zn as neighboring atoms. Hence, the Cu-Mn-Ni-Zn HEA catalyst is the promising electrocatalyst for CO 2 RR. [ABSTRACT FROM AUTHOR]

Approximately 7 at% of Yb-doped monolayer WS 2 nanosheets are successfully prepared by in-situ chemical vapor deposition technique. The performances of the photodetectors based on WS 2 (Yb) are significantly enhanced after RE doping, providing an excellent strategy for preparing high-performance 2D material optoelectronic devices. [Display omitted] • Approximately 7 at% of Yb substitutionally doped monolayer WS 2 nanosheets are prepared by in-situ chemical vapor deposition (CVD) technique. • DFT calculations demonstrate a shrinked bandgap of Yb-doped monolayer WS 2 at K point, indicating much higher of electronic states and thus higher probability of the transitions for better electronic performances. • The mobilities, photocurrents, photoresponsivity, and external quantum efficiency of the photodetector based on WS 2 (Yb) are better than those of the pristine WS 2 , proving a high effectiveness of RE doping in 2D materials and providing a guide for the preparation of 2D materials with excellent optical and optoelectronic performances. The study of rare-earth (RE) doping in two-dimensional (2D) transition metal dichalcogenides (TMDCs) has become an important research focus to modulate bandgaps and carriers for production of the exotic properties. Herein, approximately 7 at% of Yb substitutionally doped monolayer WS 2 nanosheets are prepared by in-situ chemical vapor deposition (CVD) technique. Highly enhanced optical and electrical properties are obtained: Three times enhancement in photoluminescent intensities and 5.6 nm of red-shifts in wavelength are observed from their peaks after chemical doping. First-principles calculations based on density functional theory (DFT) demonstrate a shrinked bandgap of Yb-doped monolayer WS 2 at K-point in Brillouin zone compared with that of the pristine WS 2 monolayer, and a broadened absorption and reflectivity spectra from visible to near-infrared region, which is in good agreement with the experimental results. Photodetectors based on Yb-doped monolayer WS 2 nanosheets show far higher of mobility (17 times), photocurrent, photoresponsivity, and external quantum efficiency than those of the pristine WS 2. The results prove a high effectiveness of RE doping in 2D materials for high-performance optoelectronic devices. [ABSTRACT FROM AUTHOR]