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For the most precise incorporation of single impurities in silicon, which is utilized to create quantum devices, a monolayer of adatoms on the Si(100) surface and a dopant-containing molecule are used. Here, we studied the interaction of phosphorus tribromide with a chlorine monolayer with mono- and bivacancies using a scanning tunneling microscope (STM) at 77 K. The combination of different halogens in the molecule and the adsorbate layer enabled unambiguous identification of the structures after PBr3 dissociation on Si(100)-Cl. A Cl monolayer was exposed to PBr3 in the STM chamber, which allows us to compare the same surface areas before and after PBr3 adsorption. As a result of this comparison, we detected small changes in the chlorine layer and unraveled the molecular fragments filling mono- and bivacancies. Using density functional theory, we found that the phosphorus atom occupies a bridge position after dissociation of the PBr3 molecule, which primarily bonds with silicon in Cl bivacancies. These findings provide insight into the interaction of a dopant-containing molecule with an adsorbate monolayer on Si(100) and can be applied to improve the process of single impurity incorporation into silicon. [ABSTRACT FROM AUTHOR]

Motivated by the recent experimental study on hydrogen storage in MXene multilayers [Liu et al., Nat. Nanotechnol. 16, 331 (2021)], for the first time we propose a workflow to computationally screen 23 857 compounds of MXene to explore the general relation between the activated H2 bond length and adsorption distance. By using density functional theory we generate a dataset to investigate the adsorption geometries of hydrogen on MXenes, based on which we train physics-informed atomistic line graph neural networks (ALIGNNs) to predict adsorption parameters. To fit the results, we further derived a formula that quantitatively reproduces the dependence of H2 bond length on the adsorption distance from MXenes within the framework of Pauling's resonating valence bond theory, revealing the impact of transition metal's ligancy and valence on activating dihydrogen in H2 storage. [ABSTRACT FROM AUTHOR]

Finding cost-effective and sustainable methods for the removal of hydrogen sulfide (H2S), a highly toxic gas released as a byproduct in many industrial activities, is crucial for environmental health. In this study, the adsorption and electronic sensor properties of Ti, V, Cr and Sc doped graphene nanosheets (GN) for H2S molecule have been investigated using Density Functional Theory (DFT) method. The WB97XD method with 6-31G(d,p)/LanL2DZ basis sets have been utilized in DFT calculations. The charge distribution indicates that the charge transfer occurred between metal doped graphenes and H2S. DFT calculations of H2S molecule adsorption on Ti, V, Cr and Sc doped graphenes demonstrate that the ability to adsorb H2S molecule. The obtained adsorption energy (∆E) values vary in the range of -54.4 to -71.0 kJ/mol. Furthermore, the electrical conductivity of the Cr doped graphene nanosheet (Cr-GN) changed due to the change in the HOMO–LUMO gap (∆Eg = 24.8 kJ/mol). This result indicates that the Cr-GN structure is a potential candidate as an electronic sensor for H2S molecule at room temperature. Through methods like DFT, which are cost-effective and highly compatible with experimental results, predicting suitable adsorbents, understanding their properties, and enhancing them are expected to make substantial contributions to the industrial-scale production of these materials in terms of cost and accuracy in the future. [ABSTRACT FROM AUTHOR]

This study employs density functional theory (DFT) calculations at the B3LYP/6-311+g(d,p) level to investigate the interaction of XH3 gases (X = N, P, As) with the Mn-phthalocyanine molecule (MnPc). Grimme's D3 dispersion correction is applied to consider long-range interactions. The adsorption behavior is explored under the influence of an external static electric field (EF) ranging from −0.514 to 0.514 V/Å. Chemical adsorption of XH3 molecules onto the MnPc molecule is confirmed. The adsorption results in a significant decrease in the energy gap (Eg) of MnPc, indicating the potential alteration of its optical properties. Quantum theory of atoms in molecules (QTAIM) analysis reveals partially covalent bonds between XH3 and MnPc, and the charge density differenc (Δρ) calculations suggest a charge donation-back donation mechanism. The UV-vis spectrum of MnPc experiences a blue shift upon XH3 adsorption, highlighting MnPc's potential as a naked-eye sensor for XH3 molecules. Thermodynamic calculations indicate exothermic interactions, with NH3/MnPc being the most stable complex. The stability of NH3/MnPc decreases with increasing temperature. The direction and magnitude of the applied electric field (EF) play a crucial role in determining the adsorption energy (Eads) for XH3/MnPc complexes. The Eg values decrease with an increasing negative EF, which suggests that the electrical conductivity (σ) and the electrical sensitivity (ΔEg) of the XH3/MnPc complexes are influenced by the magnitude and direction of the applied EF. Overall, this study provides valuable insights into the suggested promising prospects for the utilization of MnPc in sensing applications of XH3 gases. [ABSTRACT FROM AUTHOR]

In the last two decades, significant efforts have been particularly invested in two-dimensional (2D) hexagonal boron carbon nitride h-BxCyNz because of its unique physical and chemical characteristics. The presence of the carbon atoms lowers the large gap of its cousin structure, boron nitride (BN), making it more suitable for various applications. Here, we use density functional theory to study the structural, electronic, and magnetic properties of Pt-doped BC6N (Pt-BC6N, as well as its adsorption potential of small molecular gases (NO, NO2, CO2, NH3). We consider all distinct locations of the Pt atom in the supercell (B, N, and two C sites). Different adsorption locations are also considered for the pristine and Pt-doped systems. The formation energies of all Pt-doped structures are close to those of the pristine system, reflecting their stability. The pristine BC6N is semiconducting, so doping with Pt at the B and N sites gives a diluted magnetic semiconductor while doping at the C1 and C2 sites results in a smaller gap semiconductor. We find that all doped structures exhibit direct band gaps. The studied molecules are very weakly physisorbed on the pristine structure. Pt doping leads to much stronger interactions, where NO, NO2, and NH3 chemisorb on the doped systems, and CO2 physiorb, illustrating the doped systems' potential for gas purification applications. We also find that the adsorption changes the electronic and magnetic properties of the doped systems, inviting their consideration for spintronics and gas sensing. [ABSTRACT FROM AUTHOR]

Electrochemical fluorination on nickel anodes, also known as the Simons' process, is an important fluorination method used on an industrial scale. Despite its success, the mechanism is still under debate. One of the proposed mechanisms involves higher valent nickel species formed on an anode acting as effective fluorinating agents. Here we report the first attempt to study fluorination by means of first principles investigation. We have identified a possible surface model from the simplest binary nickel fluoride (NiF2). A twice oxidized NiF2(F2) (001) surface exhibits higher valent nickel centers and a fluorination source that can be best characterized as an [F2]− like unit, readily available to aid fluorination. We have studied the adsorption of CH4 and the co-adsorption of CH4 and HF on this surface by means of periodic density functional theory. By the adsorption of CH4, we found two main outcomes on the surface. Unreactive physisorption of CH4 and dissociative chemisorption resulting in the formation of CH3F and HF. The co-adsorption with the HF gave rise to four main outcomes, namely the formation of CH3F, CH2F2, CH3 radical, and also physisorbed CH4. [ABSTRACT FROM AUTHOR]

Context: To unravel the effects of the C vacancy, doping N type and number, the adsorption of HCHO and O2 was investigated on the graphene (Gr)-based supported Pt single atom by density functional theory calculations. The electronegativity of the vacancy and N-doped Gr was a crucial factor both for the anchoring for a Pt and the further adsorption of HCHO and O2 on the supported Pt. The electronegativity can be tuned by the C vacancy number (1V and 2V), the doping N type (graphitic-N, pyridinic-N and pyrrolic-N) and the doping pyridinic-N number (1N ~ 4N). The high electronegativity of the vacancy and N-doped Gr favored the anchoring for a Pt compared to the Gr, while too high electronegativity was detrimental for further adsorption of adsorbates on the supported Pt. The Bader charge analysis proved that the electronegativity followed the trend as pyrrolic-N > pyridinic-N > graphitic-N, and 4N-Gr > 2V-Gr > 3N-Gr > 2N-Gr > 1N-Gr > 1V-Gr > Gr. As a result, the pyridinic-N, the 1V-Gr, 1N-Gr and 2N-Gr with the suitable electronegativity achieved both stronger anchoring for a Pt and more favorable adsorption of HCHO and O2 on the supported Pt than the pristine Gr support. Methods: Periodic DFT calculation was performed using the VASP code. The PAW method and the GGA-PBE functionals were used. Part of work was also carried out by the DSPAW procedure of Device Studio. [ABSTRACT FROM AUTHOR]

The recent experimental synthesis of superalkalis has motivated us to investigate their potential application on hydrogen storage. The hydrogen adsorption mechanism of superalkali decorated graphyne were investigated by density functional theory calculations. The adsorption properties of NLi 4 and NLi 3 Na on graphyne have been investigated. The large binding energy between the superalkalis and graphyne nanosheet demonstrated that the NLi 4 and NLi 3 Na could be dispersed uniformly on graphyne without any clustering. Each NLi 4 and NLi 3 Na on graphyne can store ten and six H 2 molecules, respectively. The charge transfer, electrostatic effect, and the orbital hybridization between H, Li, and C enhanced the hydrogen adsorption energy of NLi 4 decorated graphyne. The 4NLi 4 /G and 4NLi 3 Na/G complexes can store 40 and 24H 2 molecules with a moderate average adsorption energy of −0.283 eV and −0.289 eV, resulting in the hydrogen storage density of 9.78 w. t. % and 5.65 w. t. %, respectively, surpassing the target of US DOE. These results suggested that superalkalis decorated graphyne could be considered as a promising candidate for hydrogen storage. • Strong bond and electrostatic repulsion hinder the clustering of NLi 4. • The 4NLi 4 /G storing 40H 2 with the average adsorption energy of −0.283 eV. • Each NLi 4 on graphyne capture ten H 2. • The T D ensure it to be promising candidate at operating condition. [ABSTRACT FROM AUTHOR]

The utilization of hydrogen as a clean fuel has been made feasible by the expanding development of cutting-edge materials for hydrogen adsorption and storage. In this study, we thoroughly assessed hydrogen storage capability on both neutral and charge-injected graphdiyne (GDY) nanosheets modified with Al doping and Li decorating (Li.Al-GDY). According to the findings, pure GDY has an adsorption energy of −0.093 eV, while GDY modified with Al and Li atoms has an improved adsorption energy of −0.577 eV. The highest H 2 adsorption energy of −0.760 eV was calculated for the applied charge of −2 e to the Li.Al-GDY nanosheet, indicating a significant enhancement in the adsorption energy with the charge injection. While the pristine GDY nanosheet serves as a very poor H 2 molecule adsorber and cannot even hold one H 2 molecule, the charged Li.Al-GDY nanosheet maintains 13 H 2 molecules with an average adsorption energy of −0.287 eV. According to the results, injecting charge into the nanosheet along with modification techniques such as doping and decorating can significantly boost the effectiveness of weak carbon adsorbents in terms of hydrogen adsorption. Such approaches enable the realization of the goal of using carbon adsorbents as H 2 green fuel storage. [Display omitted] • Investigation of H 2 adsorption on modified GDY nanosheet with Al doping and Li decoration. • Simultaneous modification with Al and Li increased H 2 absorption energy about 6 times. • The charge injection can effectively improve the adsorption energy of H 2. • Up to 13 H 2 molecules can be stored on Li.Al-GDY charged nanosheet with average E ads higher than 0.2 eV. [ABSTRACT FROM AUTHOR]

Stone wool is widely used as an efficient thermal insulator within the construction industry; however, its performance can be significantly impacted by the presence of water vapor. By altering the material's characteristics and effective thermo-physical properties, water vapor can reduce overall efficacy in various environmental conditions. Therefore, understanding water adsorption on stone wool surfaces is crucial for optimizing insulation properties. Through the investigation of interaction between water molecules and calcium aluminosilicate (CAS) phase surfaces within stone wool using density functional theory (DFT), we can gain insight into underlying mechanisms governing water adsorption in these materials. This research aims to elucidate the molecular-level interaction between water molecules and CAS surfaces, which is essential for understanding fundamental properties that govern their adsorption process. Both dissociative and molecular adsorptions were investigated in this study. For molecular adsorption, the adsorption energy ranged from - 84 to - 113 kJ mol - 1 depending on surface orientation. A wider range of adsorption energy (- 132 to - 236 kJ mol - 1 ) was observed for dissociative adsorption. Molecular adsorption was energetically favored on (010) surfaces while dissociative adsorption was most favorable on (111) surfaces. This DFT study provides valuable insights into the water adsorption behavior on low index surfaces of CAS phase in stone wool, which can be useful for designing effective strategies to manage moisture-related issues in construction materials. Based on these findings, additional research on the dynamics and kinetics of water adsorption and desorption processes of this thermal isolation material is suggested. [ABSTRACT FROM AUTHOR]

Zinc oxide and polylactic-co-glycolic acid (ZnO-PLGA) nanocomposites are known to exhibit different biomedical applications and antibacterial activity, which could be beneficial for adding to wound dressings after different surgeries. However, possible cytotoxic effects along with various unexpected activities could reduce the use of these prominent systems. This is correlated to the property of ZnO, which exhibits different polymeric forms, in particular, wurtzite, zinc-blende, and rocksalt. In this study, we propose a computational approach based on the density functional theory to investigate the properties of ZnO-PLGA systems in detail. First, three different stable polymorphs of ZnO were considered. Subsequently, the abilities of each system to absorb the PLGA copolymer were thoroughly investigated, taking into account the modulation of electrical, optical, and mechanical properties. Significant differences between ZnO and PLGA systems have been found; in this study, we remark on the potential use of these models and the necessity to describe crucial surface aspects that might be challenging to observe with experimental approaches but which can modulate the performance of nanocomposites. [ABSTRACT FROM AUTHOR]

Adsorption of small Te clusters on tellurene and M o S 2 monolayers have been studied within density functional framework. With adsorption on 2D monolayers, Te clusters show distortion in cluster geometry along with local distortions in the monolayer. Adsorption energy is found to be higher in T e n $ t e l l u r e n e as compared to T e n $ M o S 2 , suggesting that there exists a strong interaction between Te clusters and tellurene substrate. Adsorption of clusters on monolayers results in the modification of the effective band gap of these monolayers. Analysis of the charge density difference profile shows that a certain amount of charge is transferred from the clusters to the substrates. This results in the redistribution of the charge. Our optical calculations for the interband transitions show that Te cluster creates quantum states inside of monolayers, which leads to increasing optical absorption of the system. Additional low-intensity absorption peak, in addition to the main peak, has been noticed in cluster-adsorbed M o S 2 monolayer for E ‖ C. The real part of the dielectric function reveals the existence of plasmon frequencies. We conclude that the cluster adsorption on different monolayers alters the electronic and dielectric properties of monolayers. [ABSTRACT FROM AUTHOR]

Edge structures, thiophene adsorption and hydrodesulfurization (HDS) mechanisms are investigated on the S-edge of triangular MoS2 nanoclusters using density functional theory. The calculated formation energies for different S coverages on the S-edge suggest that the formation of coordinative unsaturated site at the vertex and edge-I (close to the vertex) sites is preferred over the edge-II (away from the vertex) sites. The adsorption of thiophene on the top site of Mo atom mainly occurs at the edge-I, whereas bridge adsorption occurs at the edge-II. The 92% and 50% S-edge coverages involve relatively larger adsorption energies (− 0.68 and − 0.79 eV) among all the possible adsorption configurations. On the S edge with 92% S coverage, the hydrogenation route is more favorable, producing 1-butene. On the S edge with 50% S coverage, the direct desulfurization route is preferred, yielding butadiene. These findings deepen the understanding of edge structures of MoS2 nanoclusters and the corresponding HDS mechanisms for MoS2-based HDS catalysts. [ABSTRACT FROM AUTHOR]

This study investigates the sensing capabilities of (8,0) SWCNTs in detecting formamide (HCONH2), a molecule crucial for the structure of proteins, nucleic acids, and certain anti-cancer drugs. Adsorption of HCONH2 on pristine SWCNT, Al- and N-doped SWCNT, and Al/N co-doped SWCNT was studied using dispersion-corrected density functional theory (DFT-D). Formamide was adsorbed from both oxygen and –NH2 sides, and the structures were fully optimization. The relaxed structures were applied for calculating magnetic and electronic properties like adsorption energies, band structures, and partial density of states. Most negative adsorption energy in doped structures indicates the strongest adsorption of formamide in doped structures than pristine SWCNT. The results also indicates that formamide adsorption does not change the electronic properties of pure SWCNT and N-doped SWCNT. However, it removes the band gaps of Al- and Al/N-doped SWCNT. Therefore, the modified nanotubes convert from semiconductor to metallic character which can be detected using electronic devices. Moreover, formamide adsorption induces some magnetization to Al-doped SWCNT and Al/N co-doped which can be utilized in spin transport devices. These findings suggest that Al/N co-doped and Al-doped SWCNTs are good candidates for detecting HCONH2 molecules. [ABSTRACT FROM AUTHOR]

[Display omitted] • The intrinsic mechanism of the external electric field effects on the N 2 adsorption and NN* dissociation performances of three-atom transition metal clusters (TATMCs) is investigated. • Electric fields regulate the charge transfer between TATMCs and NN*, thus affecting the N−N bond activation. • The ICOHP values of two N atoms and E N are not limited by the linear relationship under different electric fields. Three-atom transition metal clusters (TATMCs) with remarkable catalytic activities, especially Nb 3 , Zr 3 , and Y 3 , are proven to be suitable candidates for efficient ammonia production. The pursuit of effective strategies to further promote the ammonia synthesis performance of TATMCs is necessary. In this study, we systematically investigate the effect of external electric fields on tuning the N 2 adsorption and NN* activation performances of Nb 3 , Zr 3 , and Y 3. Our findings demonstrate that the medium and low positive fields promote the N 2 adsorption performance of Nb 3 , while both positive and negative fields enhance nitrogen adsorption on Zr 3. Additionally, electric fields may impede N 2 fixation on Y 3 , yet the N 2 adsorption performance of Y 3 remains considerable. Negative electric fields enhance the NN* activation performance of Nb 3 and Y 3. But only high negative fields weaken the N N bond on Zr 3 , which is attributed to the promotion of the charge accumulation around two N atoms. Notably, Nb 3 and Zr 3 are identified as two TATMCs with the potential for simultaneous optimization of their E N and ICOHP values. This work sheds light on the field effects on the N 2 adsorption and NN* activation performances of TATMCs and guides the design of catalysts for achieving more sustainable ammonia synthesis. [ABSTRACT FROM AUTHOR]

The adsorption of N2O on flat and defective Cu (110) surfaces has been studied using pure density functional theory (DFT) and DFT with Hubbard U, including van der Waals (vdW) corrections of the form vdW-DF. The calculations show that for GGA-PBE, as the exchange-correlation and vdW-DF functionals are considered, N2O molecule interacts very weakly with the flat Cu (110) surface, while the presence of the Cu-adatom results in better stability of adsorbed N2O compared to one on the perfect surface. Also, the inclusion of U parameter to PBE and vdW-DF functionals reduces the values of the adsorption energy relative to the standard PBE and vdW-DF functionals with or without spin-polarization. Finally, the analysis of the projected density of states shows a strong hybridization between the Cu-3d band and N-2p orbital. Our investigation suggests that the Cu (110) surface can serve as a catalytic medium that is able to adsorb the harmful N2O molecule. [ABSTRACT FROM AUTHOR]

The adsorption of anions onto metal surfaces is important in many applications including effective (electro)catalyst design, metal surface modification, and contaminant removal in wastewater treatment. In electrocatalysis, anions can be both reactive intermediates or site‐blocking spectators, where their adsorption strength therefore dictates the rate of reaction. In this work, we have measured the adsorption energy of a series of carboxylic acids on a Pt (111) single‐crystal electrode surface from aqueous solution. We find that the adsorption strength of the carboxylate anion is linearly correlated with its acid‐dissociation constant (pKa) and therefore the heterolytic O−H bond dissociation strength in solution. Using density functional theory modeling, we split the anion adsorption energy into a sum of the adsorption energy and electron affinity of a neutral (carboxyl) radical. Surprisingly, the adsorption energy of the carboxyl radicals are similar and therefore the large difference in electron affinity is what dictates anion adsorption strength; the greater the cost in energy to remove the electron from the anion upon adsorption, the weaker its binding. Therefore, at least within a class of anions with similar structure and surface binding atoms, both electron affinity and acidity are predictive descriptors of adsorption strength. [ABSTRACT FROM AUTHOR]

The adsorption of anions onto metal surfaces is important in many applications including effective (electro)catalyst design, metal surface modification, and contaminant removal in wastewater treatment. In electrocatalysis, anions can be both reactive intermediates or site‐blocking spectators, where their adsorption strength therefore dictates the rate of reaction. In this work, we have measured the adsorption energy of a series of carboxylic acids on a Pt (111) single‐crystal electrode surface from aqueous solution. We find that the adsorption strength of the carboxylate anion is linearly correlated with its acid‐dissociation constant (pKa) and therefore the heterolytic O−H bond dissociation strength in solution. Using density functional theory modeling, we split the anion adsorption energy into a sum of the adsorption energy and electron affinity of a neutral (carboxyl) radical. Surprisingly, the adsorption energy of the carboxyl radicals are similar and therefore the large difference in electron affinity is what dictates anion adsorption strength; the greater the cost in energy to remove the electron from the anion upon adsorption, the weaker its binding. Therefore, at least within a class of anions with similar structure and surface binding atoms, both electron affinity and acidity are predictive descriptors of adsorption strength. [ABSTRACT FROM AUTHOR]

The widespread use and impervious nature of per- and polyfluorinated alkyl substances (PFASs) is leading to potentially harmful exposure in numerous environments. One avenue to explore remediation of PFAS-contaminated environments involves investigating how well PFASs adsorb onto various substrates. In the current review, we focus on summarizing recent computational research, largely involving density functional theory (DFT) and molecular dynamics (MD), into the adsorption and interaction of PFASs with a variety of substrates with an aim to provide insight and inspire further research that may lead to solutions to this critical problem that impacts the environment and human health. [ABSTRACT FROM AUTHOR]

Inspired by the research of BC 2 N and Si 2 BN monolayer, a new graphene-like AlNC 2 two-dimensional structure has been proposed, and the electronical properties and H 2 adsorption capability have been investigated by using density functional theory calculations. Three types of AlNC 2 structures are designed, only AlNC 2 type I and III are stable by calculating the phonon frequencies and ab intio molecular dynamics simulations. By calculating with HSE06 functional, the indirect band gap of AlNC 2 type I is 1.762 eV, and the direct band gap of AlNC 2 type III is 1.796 eV. The hydrogen gravimetric density of pure AlNC 2 type Ⅰ and Ⅲ can reach 5.84 wt% and 8.01 wt%, which corresponds to the average adsorption energy of −0.124 eV/H 2 and -0.109 eV/H 2 , respectively. [Display omitted] • A new graphene-like AlNC 2 two-dimensional structure has been proposed. • AlNC 2 type I and III are stable by calculating phonon spectrum and AIMD simulation. • The band gap of AlNC 2 type I and Ⅲ are 1.762 and 1.796 eV with HSE06 functional. • Hydrogen storage capacity of pure AlNC 2 type I and Ⅲ can reach 5.84 and 8.01 wt%. [ABSTRACT FROM AUTHOR]

Given the superior performance of SF6 in arc extinguishing and its wide application in high voltage fields, the search for new adsorbent materials for SF6 and its main decomposition products holds significant importance in mitigating greenhouse gas potential and its implications for the environment and energy sectors. We chose ZIF-67, an organic framework with a high specific surface area and distinctive pore size structure, to address this important issue. Using the grand canonical Monte Carlo simulation approach, we investigated the adsorption of SF6 and its main decomposer gases by ZIF-67 at GPa. The interaction of ZIF-67 with SF6 and its main breakdown products was then examined at the level of atomic orbital interactions, with the adsorption energy and density of states estimated using density functional theory. The findings reveal that ZIF-67 has the best ability to capture H2S, with a saturation capacity of 3.2 mmol g−1 at room temperature. Its adsorption capacity for SOF2 and SO2F2 is about five to seven times higher than that of industrial adsorbents kdhF-03, and the working conditions are milder. The molecule radius and adsorption capacity are tightly correlated. An innovative method for the widespread recovery and treatment of SF6 and its byproducts is presented in this research. This paper aims to provide new insights and solutions to promote sustainable development in the power industry. [ABSTRACT FROM AUTHOR]

A porous organic framework containing well‐defined donor–acceptor units, named donor–acceptor porous organic framework (D–A‐POF), is successfully synthesized. The localized electric field gradient at the pore surface induced by the intramolecular donor–acceptor (D–A) interactions endows D–A‐POF with excellent desulfurization capabilities. D–A‐POF exhibits high adsorption capacity of 3‐methylthiophene (12.26 mmol g−1, 392.32 mg S g−1) and 1‐benzothiophene (793.65 mg g−1, 189.25 mg S g−1) with impressive adsorption selectivity. Density functional theory calculations provide compelling evidence of the preferential selective adsorption of aromatic thiophene sulfides in D–A‐POF. In fixed‐bed breakthrough experiments, D–A‐POF demonstrates its ability to selectively capture thiophene sulfides from model gasoline, resulting in fuel with sulfide content below 10 ppb. The high stability and high desulfurization efficiency of D–A‐POF make it promising as a new porous adsorbent for ultra‐depth adsorption desulfurization. [ABSTRACT FROM AUTHOR]

The oxidation state and charge distribution of FexOy binaries, including strained monolayers on transition metal surfaces, is a topic of significant interest. The p(2 × 2) and c(4 × 2) superstructures are two stable surface structures of chemisorbed oxygen on the pseudomorphic Fe/Ru(0001) surface that may coexist at 0.25 ML oxygen coverage. Density functional theory calculations were used to investigate the possibility of these two structures occurring on the surface. The calculations considered the effect of magnetic ordering on the choice of adsorption site for oxygen. Paramagnetic ordering of the Fe monolayer favors oxygen adsorption at the hcp site, while antiferromagnetic ordering favors oxygen adsorption at the fcc site at 0.25 ML oxygen coverage. Interestingly, in the case of antiferromagnetic ordering, although the adsorption of 1 ML coverage of oxygen for the oxidation reaction energetically prefers the hcp site, the chemisorbed structures at 0.25 ML coverage are found to prefer the fcc site on the pseudomorphic Fe/Ru(0001) surface. The DFT calculations suggest that both the p(2 × 2) and c(4 × 2) structures of oxygen are exothermic, indicating the possibility of coexistence on the pseudomorphic Fe/Ru(0001) surface and occurrence at room temperature. However, the use of the Hubbard potential parameter, which is used to correctly describe the electronic band structure of FeO and other Mott insulators, also revealed that the oxidation reaction of the pseudomorphic Fe monolayer is endothermic on the Ru(0001) surface. [ABSTRACT FROM AUTHOR]

Oil-immersed transformers play a pivotal role owing to their environmentally friendly characteristics, compact footprint, and cost-effectiveness. Ensuring the online monitoring of oil-immersed transformers is a fundamental measure to ensure the secure and stable operation of modern power systems. In this paper, metal particle cluster-doped SnS is firstly used in the adsorption and sensing of decomposition components (CO, C2H2) under fault conditions in oil-immersed transformers. The study comprehensively analyzed band structure, differential charge density, density of states, and molecular orbital theory to unveil the adsorption and sensing mechanisms of target gases. The findings suggest that the modification of metal particle clusters can enhance the surface electronic properties of single-layer SnS. In the regions of metal particle clusters and the gas–surface reaction area, electronic activity is significantly heightened, primarily attributed to the contribution of d-orbital electrons of the metal cluster structures. The modified SnS exhibits adsorption capacity in the following order: Ru3-SnS > Mo3-SnS > Au3-SnS. Additionally, the modified material demonstrates increased competitiveness for C2H2, with adsorption types falling under physical chemistry adsorption. Different metal elements exert diverse effects on the electronic distribution of the entire system, providing a theoretical foundation for the preparation of corresponding sensors. The findings in this work offer numerical insights for the further preparation and development of SnS nanosensors, concurrently shedding light on the online monitoring of faults in oil-immersed transformers. [ABSTRACT FROM AUTHOR]

Adsorption of various glycerol conformations at Brønsted sites in mordenite is studied by the density functional theory. It is shown that the adsorption energy depends on the initial conformation of the glycerol molecule and ranges from –44.0 kcal/mol (ββ conformation) to –64.7 kcal/mol (αγ conformation). In some cases, the glycerol molecule switches its conformation as a result of nanoconfinement. It is shown that the most energetically favorable adsorption of glycerol on mordenite proceeds via the primary OH group. High adsorption energy is due to the proton transfer from the zeolite Brønsted site to glycerol as a result of the hydrogen bond formation and also due to the formation of up to four additional hydrogen bonds with oxygen atoms of the zeolite framework. As a result, the backbone of the adsorbed molecule deforms, which fact should affect the course of chemical reactions involving glycerol. [ABSTRACT FROM AUTHOR]

In this study we investigate the stability of the isomers of the Li n B 3 Si 3 clusters with n = 0–7 using both density functional theory and coupled-cluster theory CCSD(T) calculations using both the def2-TZVPP and def2-QZVPP basis sets and the total energy is subsequently extrapolated to the complete basis set limit (CBS). Calculated results reveal closely spaced energies among the four most stable isomers for each size, except for n = 5. The Li 5 B 3 Si 3 isomers exhibit significant energy gaps, and a high thermodynamic stability as suggested by ΔE and Δ 2 E values for its lowest-energy isomer. Of particular importance, Li 5 B 3 Si 3 emerges as a material able to capture a large amount of molecular hydrogen. To enhance the wt%, a substitution of Si atom by a BH unit tends to yield stabilized compounds Li 5 B 3 Si 2 (BH), Li 5 B 3 Si(BH) 2 and Li 5 B 3 (BH) 3. Molecular dynamics simulations (BOMD) at up to 1200K confirm their thermal stability. Magnetic ring current maps identify them as doubly aromatic species, explaining their high stability. Each of these four Li 5 compounds can adsorb up to 24H 2 molecules with adsorption energies of 0.1–0.2 eV. The Li 5 B 3 (BH) 3 shows the most favorable wt% improvement as compared to the previously known B 12 Li 8 cluster. A survey shows that all clusters can adsorb 24H 2 at pressures up to 100 atm and temperatures below 80 K, fitting the effective range for cryo-compressed hydrogen storage. [Display omitted] • Li 5 B 3 Si 3 clusters exhibit high thermodynamic stability and efficiently and abundantly capture H 2 molecules. • All isolobal compounds Li 5 B 3 Si 3 , Li 5 B 3 Si 2 (BH), Li 5 B 3 Si(BH) 2 and Li 5 B 3 (BH) 3 are doubly aromatic species. • Each Li 5 unit adsorbs up to 24H 2 molecules, with adsorption energies lying in the range of 0.1–0.2 eV. • Li 5 B 3 (BH) 3 demonstrates a significant wt% improvement (∼30 %) as compared to the known B 12 Li 8 cluster. • The operational demands of cryo-compressed hydrogen storage of these compounds are cut to 100 atm and 80 K. [ABSTRACT FROM AUTHOR]

Polycarboxylic superplasticizers (PCEs) exhibit numerous advantages as concrete additives, effectively improving the stability and strength of concrete. However, competitive adsorption of PCEs occurs in the presence of clay, which may affect the cement dispersion and water-reducing performance. Extensive research has been conducted on the physical and mechanical properties of PCEs; however, the effect of the diverse structures of PCEs on the competitive adsorption on clay and cement hydration products has been rarely studied. This study employs Ca-montmorillonite (CaMMT) as a clay representative, by constructing adsorption models of PCEs on CaMMT and cement hydration products. A comparison of the adsorption energies considering different side-chain lengths of PCEs is included. Typically, the adsorption energy on CaMMT is lower than that on hydration products, leading PCEs to preferentially adsorb on the clay, thereby reducing its effective dosage in the cement particles. The challenge of PCE adsorption on CaMMT increases with the polymerization degree, and methylallyl polyoxyethylene ether (HPEG) exhibits lower adsorption energies on CaMMT. The density of states (DOS) analysis indicated the highest peak values of allyl polyethylene ether (APEG) as well as the peak area at n (polymerization degree) = 1. The total number of transferred electrons for APEG was 0.648, surpassing those of other PCEs. The interaction mechanism of PCEs with clay and hydration products is further elucidated through electronic gain/loss analysis, also providing a basis for the theoretical analysis on how to reduce the adsorption of PCEs on clay and the structural design of mud-resistant PCEs. [ABSTRACT FROM AUTHOR]

Modification serves as an excellent approach to enhancing the adsorption performance of biochar for tetracycline. Selective modification further allows the attainment of biochar materials that are not only more efficient but also cost-effective. However, the key structural factors influencing the adsorption of tetracycline by biochar remain unclear at present, hindering the effective guidance for modification strategies. This study established the relationship between carbonization degree and adsorption capacity, constructed a standardized microscopic model for biochar adsorption of tetracycline, and explored potential reaction mechanisms. The results indicated that with increases in the degree of carbonization, the tetracycline adsorption capacity of biochar increased from 16.08 mg L−1 to 98.35 mg L−1. The adsorption energy exhibited a strong correlation with the aromatic condensation of biochar at p ≤ 0.01, with a linear relationship (r2 ≥ 0.94). For low carbonization degrees, the adsorption of tetracycline by biochar was primarily driven by chemical bonds (69.21%) and complemented with electrostatic interactions, weak van der Waals forces or π-π interactions. For high carbonization degrees, the synergistic effects of hydrogen bonding, van der Waals forces, and π-π interactions determined the adsorption of tetracycline on biochar (91.1%). Additionally, larger carbon clusters resulted in stronger and more stable adsorption interactions. Furthermore, carboxyl-functionalized highly carbonized biochar displayed the highest reaction energy of − 1.8370 eV for adsorption of tetracycline through electrostatic interactions. This study suggests that a high degree of aromatic condensation in the carbon structure of biochar is crucial for the efficient adsorption of tetracycline. Highlights: Low-carbonized biochar primarily adsorbs tetracycline through chemical bonds. High degree of aromatic condensation facilitates biochar adsorption of tetracycline. -COOH provides the highest binding affinity for tetracycline adsorption by high-carbonized biochar. [ABSTRACT FROM AUTHOR]

Hydrogen enriched compressed natural gas contains CO and O 2 impurities, which have a coupling effect on hydrogen adsorption, dissociation and diffusion. First principles plane wave calculations have been used to study the co-adsorption and mutual interaction of H 2 +nCO + mO 2 on Fe (110) plane. The results show that it's easier for pre-adsorbed nCO + mO 2 to form high surface coverage compared with pre-adsorbed nCO or mO 2. The CO and O 2 increased H 2 dissociation barrier (E d i s − b ), and high coverage of nCO, mO 2 and nCO + mO 2 increased the hydrogen dissociation activation energy (E d i s ). With the coverage increased, the diffusion barrier (E d i f ) of H atom into Fe (110) decreased from 1.01eV to 0 by nCO and increased from 1.01eV to 2.14eV by mO 2. The E d i f was controlled by CO under low coverage and was controlled by O 2 under high coverage when nCO + mO 2 pre-adsorbed: the deformation charge density and state density analysis show that in H 2 +nCO + mO 2 system, H atom is in an electron gain state at low coverage, which is similar to H in pre-adsorbed nCO, and H is in an electron loss state at high coverage, which is similar to H in pre-adsorbed mO 2.The E d i f probably related to the charge interaction of Hx− and Hy+ with Fez+.The C, O and H formant peaks from density of states show the influence of C and O on hydrogen invasion in orbital energy. • First-principle results show that pre-adsorbed nCO + mO 2 affected H 2 adsorption, dissociation and diffusion on α-Fe (110). • The nCO, mO 2 and nCO + mO 2 increased the E d i s − b of H 2 and the adsorption capacity of dissociated H atoms decreased gradually. • The nCO promoted the diffusion of H across the surface, and the mO 2 inhibited the process, while the effect of nCO + mO 2 was controlled by coverage. [ABSTRACT FROM AUTHOR]

By using the density functional B3LYP, the impact of doping and decorating the Ni atom on the carvedilol (CV) drug delivery performance of a Ni-decorated AlN nanotube (Ni@AlNNT) and a pure AlN nanotube (PAlNNT) was investigated. The PAlNNT was not suitable for the drug delivery of CV. Doping and decorating the Ni atom into the structure of AlNNT increased the adsorption energy of CV from -5.3 to -24.3 and -31.6 kcal/mol, respectively, which demonstrated that the sensitivity of the Ni@AlNNT increased more compared to the case of Ag-doping. To examine the solvent effect on the adsorption energy for CV/Ni@AlNNT, which was -29.4 kcal/mol, the polarizable continuum model (PCM) was employed. There was a slight decrease in the sensing response of the AlNNT to CV in the water solvent. Finally, the adsorption capacity and performance of CV increased after doping and decorating the Ni atom, especially after decorating the Ni atom, which made the AlNNT more favorable for the drug delivery of CV. [ABSTRACT FROM AUTHOR]

Based on density functional theory (DFT) with van der Waals (vdW) corrections, the adsorption mechanisms of hydrazine (N2H4) and methane (CH4) molecules on Li3B12 cluster were systematically studied according to the adsorption energy, consecutive adsorption energy, adsorption distance, charges transfer, electron deformation density, electrostatic potential surface, and density of states. Our results expose the Li atoms transfer their electrons to the neighbored B atoms with positively charged and results in a strong binding capacity for N2H4 and CH4 molecules adsorption. Li3B12 cluster can adsorb up to nine N2H4 molecules and nine CH4 molecules with an optimal adsorption energy of − 0.946 eV and − 0.248 eV, respectively. Meanwhile, the storage capacity of N2H4 and CH4 reaches up to 65.3 wt.% and 48.5 wt.% and realizes the remarkable storage capacity of gas molecules. Also, the obtained adsorption properties reflect the storage mechanisms of gas (N2H4 or CH4) molecules mainly come from charges redistribution under generated electrostatic field and orbital hybridization between Li3B12 cluster and adsorbed molecules. Moreover, the amount of exchanged charge (QT) between adsorbed molecule and Li3B12 cluster clearly manifests electrons are migrated from gas molecules to Li3B12 cluster as well as the gas molecule plays the role of electron donor. In addition, ab initio molecular dynamics (AIMD) simulations based on canonical (NVT) ensemble with Nose–Hoover (NH) heat bath indicate the N2H4 and CH4 molecules are not dissociated at room temperature of 300 K, which verifies the Li3B12 cluster possesses a favorable thermal stability. Our theoretical calculations reveal Li3B12 cluster can be served as an efficient and excellent media for N2H4 and CH4 storage, detection and transportation. [ABSTRACT FROM AUTHOR]

In natural kaolinite lattices, A l 3 + can potentially be substituted by cations such as M g 2 + , C a 2 + , and F e 3 + , thereby influencing its adsorption characteristics towards rare earth elements like S c 3 + . Density functional theory (DFT) has emerged as a crucial tool in the study of adsorption phenomena, particularly for understanding the complex interactions of rare earth elements with clay minerals. This study employed DFT to investigate the impact of these three dopant elements on the adsorption of hydrated S c 3 + on the kaolinite (001) Al-OH surface. We discerned that the optimal adsorption configuration for hydrated S c 3 + is S c (H 2 O) 8 3 + , with a preference for adsorption at the deprotonated Ou sites. Among the dopants, Mg doping exhibited superior stability with a binding energy of −4.311 eV and the most negative adsorption energy of −1104.16 kJ/mol. Both Mg and Ca doping enhanced the covalency of the Al-O bond, leading to a subtle shift in the overall density of states towards higher energies, thereby augmenting the reactivity of the O atoms. In contrast, Fe doping caused a pronounced shift in the density of states towards lower energies. Compared to the undoped kaolinite, Mg and Ca doping further diminished the adsorption energy of hydrated S c 3 + and increased its coordination number, while Fe doping elevated the adsorption energy. This study offers profound insights into understanding the role of dopant elements in the adsorption of hydrated S c 3 + on kaolinite. [ABSTRACT FROM AUTHOR]

The current work investigated the interaction of ZnO nanoparticles (NPs) with glycine, tyrosine, methionine and phenylalanine. (ZnO)12 cage-like cluster was modeled using the density functional theory to determine the adsorption energy, the preferred sites for adsorption of amino acids, and the electronic structure of the formed complexes. The findings suggest that pure amino acids interact with (ZnO)12 via a chemisorption process. The thermodynamic parameters computed showed that the complexation is an exothermic process and enthalpy-driven. The oxygen atoms in the carboxyl groups of the four studied amino acids are involved in the adsorption process. PHE_Zn12O12 exhibits the highest adsorption energy (− 207.50 kJ/mol) due to its interaction with the Zn12O12 nanocluster through two different adsorption sites. The electronic and sensing properties were examined by analyzing the HOMO and LUMO energies and the HOMO–LUMO energy gap (|ΔEg|). The sensitivity of Zn12O12 nanocluster toward the studied amino acids was examined by comparing the percentage variation of the gap after the adsorption, which can reach the value of 38%, suggesting the potential of Zn12O12 nanocluster as a promising sensor for the detection of amino acids. Interaction region indicator (IRI) analysis was performed for a visual understanding of the different interactions occurring between the amino acids and the Zn12O12 nanocluster. The results of this study can shed some light on the possible application of ZnO-based nanobiosensors for detecting protein tyrosine/tryptophan nitration as an early symptom of several serious chronic diseases. [ABSTRACT FROM AUTHOR]

The adsorption and dissociation of molecular oxygen on the surface of N-graphene/Au/Ni(111) epitaxial system with high crystalline quality of N-graphene have been investigated. The system is formed in such a way that nitrogen impurities in it are exclusively represented by graphitic and pyridinic configurations in equal concentrations. Using X-ray photoelectron spectroscopy and density functional theory calculations, the relationship between the chemical shift of the N 1s core level caused by the adsorption of molecular oxygen and the atomic position of individual oxygen atoms after molecular dissociation has been established. [ABSTRACT FROM AUTHOR]

Platinum electrocatalysts on graphene-like supports have recently attracted research interest as components of electrochemical devices based on hydrogen oxidation reactions in acid media due to their improved electrochemical properties, high stability, and conductivity. Within the current work, hydrogen adsorption and the recombination effects of a proton and hydroxonium on a graphene-based electrocatalyst were investigated using density functional theory. The interaction between ions and the platinum surface was simulated for various configurations, including different initial ion distances and angles relative to the surface of the graphene sheet as well as different adsorptions on various Pt atoms (vertices or faces for Pt13 and Pt14 nanoclusters). Then, the geometry optimization was performed. Changes in the density of states during the reactions were studied to analyze the occurrences and alterations of the interactions. A comparative analysis of the obtained adsorption energies of H+ and H3O+ with experimental data was conducted. The energy was calculated to be less in absolute value, and intermediates were more stable in adsorption models with the H–Pt–Gr angle of 90° than in models with the angle of 180°. Strong chemical bonding for models with H–Pt distances less than 2 Å was observed from the DOS. [ABSTRACT FROM AUTHOR]

Theoretical and experimental investigations have shown that biochar, following KOH activation, enhances the efficiency of NO removal. Similarly, NaOH activation also improves NO removal efficiency, although the underlying mechanism remains unclear. In this study, zigzag configurations were employed as biochar models. Density functional theory (DFT) was utilized to examine how Li and Na single adsorption and OH co-adsorption affect the reaction pathways of NO reduction on the biochar surface. The rate constants for all reaction-determining steps (RDSs) within a temperature range of 200 to 1000 K were calculated using conventional transition state theory (TST). The results indicate a decrease in the activation energy for NO reduction reactions on biochar when activated by Li and Na adsorption, thus highlighting their beneficial role in NO reduction. Compared to the case with Na activation, Li-activated biochar exhibited superior performance in terms of the NO elimination rate. Furthermore, upon the adsorption of the OH functional group onto the Li-decorated and Na-decorated biochar models (LiOH-decorated and NaOH-decorated chars), the RDS energy barriers were higher than those of Li and Na single adsorption but easily overcome, suggesting effective NO reduction. In conclusion, Li-decorated biochar showed the highest reactivity due to its low RDS barrier and exothermic reaction on the surface. [ABSTRACT FROM AUTHOR]

Context: To explore the impact of OGs (OGs) on formaldehyde (HCHO) adsorption by modified activated carbon, this paper studied the influence of OGs on HCHO adsorption characteristics, varying the groups including ester, carboxyl, and hydroxyl. Employing density functional theory (DFT), the effects of various OGs on the structure of N-doped activated carbon through GGA-PBE exchange-correlation functionals by Materials Studio combined with Gaussian software. The types of weak interactions during the adsorption process were calculated by RDG, elucidating the mechanism through which the three OGs affect HCHO adsorption on N-doped activated carbon. The dynamic adsorption process of HCHO was simulated by molecular dynamics (MD). The influence and proportion of OGs on HCHO adsorption were subsequently analyzed using van der Waals and electrostatic interactions, determining differences in formaldehyde adsorption effects across OG types. The carboxyl group exhibits the most robust synergistic adsorption effect on the modified activated carbon. There is a notable alteration in the position and distribution of electrostatic potential extremes observed following carboxyl modification. The calculation results show that the adsorption energy of hydroxyl groups on modified activated carbon is the highest, at −5.07 kcal/mol, with a transfer charge of 0.014 e. Following the introduction of carboxyl groups, the proportion of electrostatic interactions escalated from the initial 24% to 38%. This study will provide new ideas for guiding the design of activated carbon for efficient adsorption of formaldehyde. Methods: The modified activated carbon fragments of three OGs were constructed by Materials Studio and Gaussian software, and the surface electrostatic potential polarity and area distribution, charge change, adsorption energy, and transferred charge of each molecular fragment were calculated. Moreover, cell models of OGs with the same dimensions were constructed to simulate the adsorption amount, heat of adsorption, interaction energy, radial distribution function, and hydrogen-bonding interactions for methane at room temperature and pressure. The results were consistent with the DFT simulations. [ABSTRACT FROM AUTHOR]

Owing to the huge increase in population and industrial activity over the past century, the natural air environment is becoming increasingly polluted. Therefore, it is essential to monitor and regulate pollution levels. Numerous research efforts have been conducted to create acceptable gas-sensitive materials for continuing monitoring and sounding alarms when dangerous chemical vapors are present at higher than intended levels. In the theoretical analysis of the adsorption properties, density functional theory calculations were utilized for B 12 Y 12 (Y N, P, As, Sb) nanocages as gas sensor towards common air pollutants, CO 2 and H 2 molecules. In this study, the geometrical and electronic properties, highest occupied molecular orbital (HOMO) – lowest unoccupied molecular orbital (LUMO) energy gap, frontier molecular orbital (FMO) analysis were investigated. The shortest H 2 and CO 2 distances after the adsorption process were for B 12 N 12 with distances less than 2.8 Å and 2.2 Å, respectively, and the adsorption energy when CO 2 was adsorbed on the B 12 N 12 surface was less than −26 kJ/mol, indicating that adsorption occurred physically and exorthemically. The Eg of B 12 N 12 is 5.9 eV; therefore, compared to others, this nanocage is the most stable for H 2 and CO 2 adsorption. In addition, a positive ∇2ρ value and negative H value from the QTAIM analysis indicated the formation of moderate interaction between B 12 N 12 and CO 2. Density of states (DOS) and natural bond orbital (NBO) studies were performed to better understand the nanocage adsorption properties, which revealed the presence of physical interactions. Energy decomposition analysis was performed to investigate the stability of gas adsorption onto a nanocage surface. The results showed that Δ E D I S P and Δ E E L E C were significant factors in determining the adsorption process stability, and the adsorption type was physisorption based on Δ E P O L value for all nanocages. Molecular dynamics (AIMD simulation) analysis revealed changes in the bond lengths and angles during adsorption. This work provides the first theoretical framework for the carbon monoxide and hydrogen adsorption performance of B 12 Sb 12 and B 12 As 12. • CO 2 and H 2 adsorption on B 12 Y 12 (Y N, P, As, Sb) has been investigated by DFT-D4. • B3LYP-D4/LANL2DZ level of theory has been utilized for this investigation. • B 12 N 12 is the most stable nanocage for CO 2 and H 2 adsorption. • The adsorption of CO 2 and H 2 on the B 12 N 12 occurs physically and exothermically. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O), as the third largest greenhouse gas in the world, also has great applications in daily life and industrial production, like anesthetic, foaming agent, combustion supporting agent, N or O atomic donor. The capture of N2O in adipic acid tail gas is of great significance but remains challenging due to the similarity with CO2 in molecular size and physical properties. Herein, the influence of cation types on CO2−N2O separation in zeolite was studied comprehensively. In particular, the inverse adsorption of CO2−N2O was achieved by AgZK‐5, which preferentially adsorbs N2O over CO2, making it capable of trapping N2O from an N2O/CO2 mixture. AgZK‐5 shows a recorded N2O/CO2 selectivity of 2.2, and the breakthrough experiment indicates excellent performance for N2O/CO2 separation. The density functional theory (DFT) calculation shows that Ag+ has stronger adsorption energy with N2O, and the kinetics of N2O is slightly faster than that of CO2 on AgZK‐5. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O), as the third largest greenhouse gas in the world, also has great applications in daily life and industrial production, like anesthetic, foaming agent, combustion supporting agent, N or O atomic donor. The capture of N2O in adipic acid tail gas is of great significance but remains challenging due to the similarity with CO2 in molecular size and physical properties. Herein, the influence of cation types on CO2−N2O separation in zeolite was studied comprehensively. In particular, the inverse adsorption of CO2−N2O was achieved by AgZK‐5, which preferentially adsorbs N2O over CO2, making it capable of trapping N2O from an N2O/CO2 mixture. AgZK‐5 shows a recorded N2O/CO2 selectivity of 2.2, and the breakthrough experiment indicates excellent performance for N2O/CO2 separation. The density functional theory (DFT) calculation shows that Ag+ has stronger adsorption energy with N2O, and the kinetics of N2O is slightly faster than that of CO2 on AgZK‐5. [ABSTRACT FROM AUTHOR]

Stimulated by the recent synthesis of penta-NiN 2 sheet [ ACS Nano 2021 , 15 , 13,539], we study the hydrogen adsorption on the sheet and the derived nanotubes by using density functional theory with the correction of van der Waals interactions. We have found that each Ni site can only adsorb two hydrogen molecules as expected from the 18-electron rule, the corresponding capacity is 4.44 wt%. As more H 2 molecules are introduced, H 2 can only be very weakly adsorbed on N sites. When the sheet is curved into nanotubes, the Ni–N distance is enlarged due to the stress, which weakens the orbital hybridizations between Ni and N, and reduces the charge transfer from Ni to N. The Ni ion with a less charge on the tube shows weak polarizing ability for H 2 molecule. • Penta-sheet and nanotube for hydrogen storage. • Each Ni site in the penta-NiN 2 sheet can only adsorb two H 2 molecules. • The perfect penta-NiN 2 sheet can't reach the DOE target for H 2 storage. • N-vacancy, Ni replacement, and grain boundary need to be introduced to enhance the adsorption energy and capacity. [ABSTRACT FROM AUTHOR]

As a promising candidate for accident-tolerant fuel (ATF) cladding materials, FeCrAl alloys are susceptible to hydrogen embrittlement (HE) under high-temperature radioactive water environments. Understanding the HE mechanism of FeCrAl is crucial, and studying H 2 dissociative adsorption can provide valuable insights since it is the first step in the HE processes. In this paper, we investigated the H 2 dissociative adsorption on Fe (110) and FeCrAl (110) surfaces using first-principles calculations based on Density Functional Theory (DFT). Our results indicate that the decomposition of H 2 molecules on FeCrAl (110) surfaces is significantly affected by surface elemental effects compared to Fe (110) surfaces. Specifically, Al atoms weaken both the H 2 decomposition and the H binding strength of Al-containing sites. Cr atoms decrease the decomposition tendency of H 2 in certain configurations, but Cr aggregation enhances the binding strength of H atoms on Cr-containing sites. The mechanism underlying the Al/Cr weakening effects on H 2 decomposition is due to the charge deficiency through alloying. Our findings have generalized implications for studying the interactions between iron-based alloys and hydrogen in various applications such as hydrogen storage, transportation, and prevention. • The strength of H 2 –Fe/Cr/Al interactions follow the order: H 2 –Al < H 2 –Cr < H 2 –Fe. • Al atoms have strong weakening effect on H 2 dissociation compared to Fe. • Cr atoms have slight weakening effect on H 2 dissociation compared to Fe. • The Cr aggregation can enhance H 2 –Cr interaction & H binding strength. • The weakening effects of Al & Cr on H 2 dissociation are caused by the charge deficit of Al & Cr after alloying with Fe. [ABSTRACT FROM AUTHOR]

B 4 C 12 achieves a rapid and stable CO 2 adsorption with a novel η3(O, C, O)-CO 2 configuration, and a small limiting potential for CO2RR producing HCOOH associating with suppressed HER. [Display omitted] The electrochemical reduction of CO 2 (CO2RR) to formic acid (HCOOH) is a promising approach to harness renewable energy for the production of value-added chemicals and contribute to carbon cycling. The search for cost-effective and efficient metal-free electrocatalysts is critical for realizing industrial applications. However, limited literature is available on this topic, primarily because the significant challenge of efficiently activating inert CO 2 remains unresolved. In this study, we have designed and applied a novel boron carbide (B 4 C 12) monolayered cage as an electrocatalyst for CO2RR to produce HCOOH. B 4 C 12 exhibits exceptional electronic, dynamic, and thermodynamic stability. Through comprehensive density functional theory computations, we have observed that B 4 C 12 rapidly and stably adsorbs CO 2 in a unique η3(O, C, O)-CO 2 configuration, resulting in excellent CO2RR activity with a low limiting potential (–0.38 V) and suppressed hydrogen evolution reaction. Our mechanistic investigations reveal that B 4 C 12 donates electrons to facilitate the bending of CO 2 , anchoring it onto the curved surface effectively. Additionally, the C atom in the η3(O, C, O)-CO 2 configuration attracts H+ + e− pairs through its active p electron, leading to the observed low limiting potential. This study not only successfully designs a novel class of metal-free electrocatalysts but also provides a promising strategy for advancing CO2RR research in the future. [ABSTRACT FROM AUTHOR]

Many phenomena remain to be investigated regarding the micro adsorption kinetics of hydrogen storage in different carbon nanomaterials. The hydrogen adsorption behaviour on the wall surface of the conical graphene layers (CGL) of three kinds of different cup-stacked carbon nanotubes (CSCNTs) is investigated using density functional theory (DFT). Furthermore, Pt decoration of the CGL wall was also investigated. The hydrogen adsorption result of the Pt-CGL is examined through the charge transfer and electron density difference approach. The optimisation results show that as the cone angle increases, the hydrogen adsorption capacity on the outside of the CGL wall increases gradually. In contrast, the hydrogen adsorption capacity on the inside of the wall decreases as the cone angle increases. The adsorption energy (E ads) of intrinsic CGL can only reach 5 kJ/mol, and the E ads of defective CGL can reach 10 kJ/mol. In contrast, the E ads of Pt-CGL can reach more than 30 kJ/mol, indicating that the hydrogen adsorption capacity of the CGL can be effectively increased by the Pt atom decoration, which can meet the adsorption energy target of hydrogen storage material formulated by the United States Department of Energy (DOE). [Display omitted] • The hydrogen adsorption behaviour on the cup-stacked carbon nanotube wall surface was investigated. • The conical graphene layer wall has weak physical adsorption on hydrogen. • With the cone angle increase, the inside of the conical graphene layer wall adsorption capacity decreases. • The adsorption energy of the C–Pt–H 2 unit can meet the United States Department of Energy targets. • The adsorption behaviour of the C–Pt–H2 unit belongs to Kubas coordination. [ABSTRACT FROM AUTHOR]

The selective photocatalytic reduction of CO2 to CH4 remains a challenge because there is a need for not only strong adsorption sites for the intermediates, but also optimal proton-feeding sites on the photocatalyst surface. Herein, a synergistic dual-site function between in situ-generated Ni0 and Ni2P on carbon nitride nanosheets (CN) for photocatalytic reduction of CO2 to CH4 is presented. The highest CH4 production rate of 69.03 μmol g−1 h−1 is achieved on Ni2P/CN-0.5 in an aqueous suspension. Detailed analyses show that the promotion of CH4 is closely correlated with the formation of Ni0 sites due to light irradiation, which is confirmed by tracking the compositions of Ni2P/CN-0.5 through XPS and HRTEM characterization. Density functional theory calculations have been combined with CO-TPD and in situ FTIR spectra to reveal the synergy between in situ-generated Ni0 sites and Ni2P. It shows that the Ni0 sites can stabilize the key intermediate *CO, while the Ni0–Ni2P interface can promote *H transfer from Ni2P to Ni0. Therefore, the CO intermediates are rapidly protonated to form CHO* instead of being desorbed from the surface to produce CO, and subsequently CHO* will be converted into CH4. This work demonstrates a new strategy of designing highly efficient photocatalysts with synergistic catalytic sites for CO2 conversion to hydrocarbons. [ABSTRACT FROM AUTHOR]

Density functional theory calculations are performed to analyze the structure and stability of Cu and Cu‐K clusters with 3 to 9 atoms. The results indicate that the stability of the clusters decreases after doping with a K atom. With the increase of cluster size, the stability of the clusters shows odd‐even alternation. Cu8 and Cu7K clusters exhibit the highest stability. Next, different adsorption sites are considered to investigate the geometry of CunNO and Cun−1KNO clusters. By calculating the adsorption energy and the HOMO‐LUMO energy gap, it is determined that both types of reactions are exothermic processes, indicating stable adsorption of NO. Notably, the CunK clusters are more active (stronger adsorption) for NO than the Cun clusters. The most chemically active clusters among CunNO and Cun−1KNO clusters are Cu8NO and Cu7KNO clusters. Finally, electron transfer and Mayer bond order analysis of Cu8NO and Cu7KNO clusters reveal that the NO bond order decreases due to electron transfer when Cu/Cu‐K clusters adsorb NO. In this process, the N atom is the electron donor and the Cu atom is the electron acceptor. Fundamental insights obtained in this study can be useful in the design of Cu/Cu‐K catalysts. [ABSTRACT FROM AUTHOR]

The interaction behavior of HCl and (ZnS)n (n = 1–12) clusters and HCl effect on Hg0 adsorbed by (ZnS)n have been studied theoretically. The combined genetic algorithm and density functional theory (GA‐DFT) method has been used to obtain the structures of (ZnS)nHCl and (ZnS)nHgHCl (n = 1–12) clusters. The structural properties of (ZnS)nHCl and (ZnS)nHgHCl have been analyzed. The adsorption energies and interaction energies have been calculated. Bond length and bond order analysis has revealed that SH and ZnCl bonds form after HCl adsorbed on (ZnS)n clusters, while Hg0 can only weakly bind with (ZnS)nHCl clusters. According to thermodynamic adsorption analysis, the formation of (ZnS)nHCl clusters from (ZnS)n and HCl are spontaneous because of their negative Gibbs free energy changes. The formation of (ZnS)nHgHCl from (ZnS)nHCl and Hg are nonspontaneous for n = 1–4 and 9, and the Gibbs free energy changes have small negative values for other sizes. Electron localization function and noncovalent interaction (NCI) analysis of (ZnS)10HgHCl manifest that Hg and its nearest Zn form zinc amalgam. Projected density of state study has been performed to obtain the interaction nature of HCl and (ZnS)n clusters and Hg0 adsorption on (ZnS)nHCl clusters. Based on our study, HCl is chemical adsorbed by (ZnS)n clusters except (ZnS)4 cluster. After (ZnS)n adsorbs HCl, Hg0 can physically adsorb on (ZnS)nHCl clusters. The strength of Hg0 on (ZnS)nHCl is comparable to that of Hg0 on (ZnS)n, indicating that HCl can hardly affect the adsorption of Hg0 on ZnS clusters. [ABSTRACT FROM AUTHOR]

Temperature, concentration and pore size constitute critical factors influencing adsorption and diffusion in tobacco. Investigating the adsorption and diffusion behavior of tobacco not only advances fundamental theory but also provides practical guidance for the tobacco industry to optimize cigarette quality and performance through adjustments in production conditions. This study reports a multiscale simulation framework exploring the adsorption and diffusion of water, propylene glycol, glycerol and nicotine under the influence of these key factors. First-principles density functional theory calculations reveal the preference of H2O to adsorb on O-top rather than H-top sites due to weak hydrogen bond interactions. Additionally, molecular dynamics simulations demonstrate that with increase in temperature, the diffusion properties of H2O and other components enhance, attributed to intensified thermal vibrations and increased kinetic energy of the adsorbent. Intriguingly, with increase in concentration, the diffusion properties of all adsorbents initially increase and then decrease, intricately linked to hydrogen bond effects on system stability and the availability of accommodation space in the porous structure of cellulose. Furthermore, as pore size enlarges, the diffusion of adsorbents significantly increases due to the expansion of free space. In summary, the objective of this study is to provide a profound theoretical understanding for the cigarette industry, thereby contributing to the improvement of cigarette quality and flavor. [ABSTRACT FROM AUTHOR]

To improve the adsorption efficiency of pollutants by biochar, preparing graphene-like biochar (GBC) or nitrogen-doped biochar are two commonly used methods. However, the difference in the nitrogen doping (N-doping) effects upon the adsorption of pollutants by pristine biochar (PBC) and GBC, as well as the underlying mechanisms, are still unclear. Take the tetracycline (TC) as an example, the present study analyzed the characteristics of the adsorption of TCs on biochars (PBC, GBC, N-PBC, N-GBC), and significant differences in the effects of N-doping on the adsorption of TCs by PBC and GBC were consistently observed at different solution properties. Specifically, N-doping had varied effects on the adsorption performance of PBC, whereas it uniformly improved the adsorption performance of GBC. To interpret the phenomenon, the N-doping upon the adsorption was revealed by the QSAR model, which indicated that the pore filling (VM) and the interactions between TCs with biochars (Ead-v) were found to be the most important two factors. Furthermore, the density functional theory (DFT) results demonstrated that N-doping slightly affects biochar's chemical reactivity. The van der Waals (vdWs) and electrostatic interactions are the main forces for TCs-biochars interactions. Moreover, N-doping mostly strengthened the electrostatic interactions of TCs-biochars, but the vdWs interactions of most samples remained largely unaffected. Overall, the revealed mechanism of N-doping on TCs adsorption by biochars will enhance our knowledge of antibiotic pollution remediation. [ABSTRACT FROM AUTHOR]

MXene, a two-dimensional (2D) nanomaterial with diverse applications, has gained significant attention due to its 2D lamellar structure, abundance of surface groups, and conductivity. Despite various established synthesis methods since its discovery in 2011, MXenes produced through different approaches exhibit variations in structural and physicochemical characteristics, impacting their suitability for environmental application. This study delves into the effect of synthesis conditions on MXene properties and its adsorption capabilities for four commonly prescribed antibiotics. We utilized material characterization techniques to differentiate MXenes synthesized using three prevalent etchants: hydrofluoric acid (HF), mixed acids (HCl/HF), and fluoride salts (LiF/HCl). Our investigation of adsorption performance included isotherm and kinetic analysis, complemented by density functional theory calculations. The results of this research pinpointed LiF/HCl as an efficient etchant, yielding MXene with favorable morphology and surface chemistry. Electrostatic interactions and hydrogen bonding between MXene surface terminations and ionizable moieties of the antibiotic molecules emerge as pivotal factors in adsorption. Specifically, a higher presence of oxygen terminations increases the binding affinities. These findings provide valuable guidance for etchant selection in environmental applications and underscore the potential to tailor MXenes through synthesis conditions to design membranes capable of selectively removing antibiotics and other targeted substances. [ABSTRACT FROM AUTHOR]