Search

• A method is developed to synthesize carbon-based high ni loaded single atom catalysts. • Ni single atom in catalysts with high photochemical activity exist as Ni-N and Ni-O. • The apparent rate constant for TC degradation by 5%Ni-C-Si is 0.169 min−1. • h +and ·O 2 − produced in photocatalysis are dominantly responsible for TC degradation. Environmental photocatalysis is a promising technology for treating antibiotics in wastewater. In this study, a supercritical carbonization method was developed to synthesize a single-atom photocatalyst with a high loading of Ni (above 5 wt.%) anchored on a carbon-nitrogen-silicate substrate for the efficient photodegradation of a ubiquitous environmental contaminant of tetracycline (TC). The photocatalyst was prepared from an easily obtained metal-biopolymer-inorganic supramolecular hydrogel, followed by supercritical drying and carbonization treatment. The low-temperature (300°C) supercritical ethanol treatment prevents the excessive structural degradation of hydrogel and greatly reduces the metal clustering and aggregation, which contributed to the high Ni loading. Atomic characterizations confirmed that Ni was present at isolated sites and stabilized by Ni-N and Ni-O bonds in a Ni-(N/O) 6 C/SiC configuration. A 5% Ni-C-Si catalyst, which performed the best among the studied catalysts, exhibited a wide visible light response with a narrow bandgap of 1.45 eV that could efficiently and repeatedly catalyze the oxidation of TC with a conversion rate of almost 100% within 40 min. The reactive species trapping experiments and electron spin resonance (ESR) tests demonstrated that the h+, and ·O 2 − were mainly responsible for TC degradation. The TC degradation mechanism and possible reaction pathways were provided also. Overall, this study proposed a novel strategy to synthesize a high metal loading single-atom photocatalyst that can efficiently remove TC with high concentrations, and this strategy might be extended for synthesis of other carbon-based single-atom catalysts with valuable properties. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] Interactions between manganese (Mn) and iron (Fe) are widespread processes in soils and sediments, however, the abiotic transformation mechanisms are not fully understood. Herein, Mn(II) oxidation on hematite were investigated at various pH under oxic condition. Mn(II) oxidation rates increased from 3 × 10−4 to 8 × 10−2 h−1 as pH increased from 7.0 to 9.0, whereas hematite enhanced Mn(II) oxidation rates to 1 h−1. During oxidation process, high pH could promote the oxidation of Mn(II) into Mn minerals, resulting in the rapid consumption of the newly-formed H+, and high pH facilitated Mn(II) adsorption and oxidation by altering Mn(II) reactivity and speciation. Only granule-like hausmannite was found on the hematite surface at pH 7.0, whereas hausmannite particles and feitknechtite and manganite nanowires were formed at pH from 7.5 to 9.0. Moreover, a co-shell structured nanowire composed of manganite and feitknechtite was observed owing to autocatalytic reactions. Specifically, electron transfers between Mn(II) and O 2 occurred on the surface or through bulk phase of hematite, and direct electron transfers in the O 2 -Mn(II) complex and indirect electron transfers in the O 2 -Fe(II/III)-Mn(II) complex may both have contribution to the overall reactions. The findings provide a comprehensive interpretation of Fe-Mn interaction and have implications for the formation of soil Fe-Mn oxyhydroxides with unique properties in controlling element cycling. [ABSTRACT FROM AUTHOR]

The widespread adoption of electric vehicles has become pivotal in attaining emissions reduction objectives, and the rationale behind designing and situating charging stations determines the unfurling of electric vehicles. This scholarly work fully mines the geographical situational particulars underlying the functioning statistics of charging stations in Beijing during the period from January to March 2016. By incorporating the urban road network, we construct a charging stations accessibility index to investigate the influence of stations accessibility on utilization rates. The findings reveal a substantial positive relationship between the overall accessibility of charging stations and their utilization rates. However, the limited number of charging stations hinders the agglomeration effect from significantly boosting utilization rates. Moreover, the impact of charging station accessibility on utilization rates varies significantly across regions with different levels of development, indicating pronounced heterogeneity. The research conclusions of this paper provide useful suggestions for promoting the rational layout of charging stations. [Display omitted] • Charging station accessibility depends on driving distance to important city areas. • The accessibility of charging stations significantly impacts their utilization rate. • Charging station accessibility's impact on utilization rate varies significantly across regions. • Insufficient charging stations limit agglomeration's impact on utilization rates. [ABSTRACT FROM AUTHOR]

Bipyridine-containing covalent triazine framework (CTF-Bpy) was used to prove that the single site distribution of Co2+ was possible. The Co2+-loaded CTF-Bpy-Co produced 120 μmol CO with a selectivity of 83.8% over 10 h of irradiation (>420 nm). This work highlights the promising potential of single metal sites loaded with CTFs for photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

Objective. To study the feasibility of intensity modulated radiation therapy (IMRT) for stage N0 nasopharyngeal carcinoma (NPC) and its parotid gland (PG) function preservation from physical and dosimetric aspects. Methods. All the clinical data of 77 patients with pathologically confirmed T1-4N0M0 NPC who received radiotherapy between July 2017 and October 2019 in the Radiotherapy Center of Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University were analyzed retrospectively. Three-dimensional conformal radiotherapy (3D-CRT) and IMRT were used in 35 and 42 cases, respectively. The treatment efficiency and the dosimetry differences of the PG in the intensity modulation plan were compared between groups. Quantitative monitoring of 99mTc radionuclide imaging of PG was performed before, at the end of, and 3, 6, and 12 months after radiotherapy. The degree of PG function injury and xerostomia was compared between groups at the end of radiotherapy and 12 months later. Results. Higher minimal, maximal, and average irradiation doses of PG were determined in 3D-CRT-treated patients compared with IMRT-treated cases (P < 0.05). Compared with before radiotherapy, the PG uptake index (UI) and excretion index (EI) of both cohorts of patients decreased to varying degrees at the end of radiotherapy, with PG function injury and xerostomia symptoms observed in all cases but with no obvious difference between groups (P > 0.05). To a certain extent, the PG function recovered and the xerostomia symptoms relieved in both groups 12 months after radiotherapy, with better improvements in IMRT group versus 3D-CRT group. Conclusion. IMRT has similar short-term efficacy to 3D-CRT in treating patients with stage N0 NPC, but it can effectively reduce the dose of PG radiotherapy and protect the PG function on the premise of ensuring sufficient tumor coverage and dose, showing certain dosimetry advantages. [ABSTRACT FROM AUTHOR]

Objective. Parotid gland (PG) is a radiosensitive organ, and xerostomia (XS) is a key factor affecting patients' life quality after conventional radiotherapy for head and neck tumors. In this study, dosimetry analysis was performed on PG stem cell preservation in intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods. All clinical data of 80 NPC patients diagnosed pathologically in the Radiotherapy Department of Taizhou Hospital of Zhejiang Province Affiliated with Wenzhou Medical University from August 2017 to September 2019 were retrospectively analyzed. Patients were assigned to a regular group and a restricted group according to different IMRT plans, in which a dose limitation for the parotid duct was added in the restricted group in addition to the conventional plan used in the regular group to minimize the parotid duct radiation dose. The differences in planning target volume (PTV) dose distribution, organ at risk (OAR) dose, and dose to the PG and its ducts were compared between the two groups. Results. Significantly higher mean irradiation doses of the brainstem, mandible, and oral cavity were determined in the restricted group compared with the regular group (P > 0.05), but there was no significant difference in the mean dose of other OARs irradiated (P > 0.05). As compared to the irradiation of bilateral PGs, no statistical differences were found in the mean irradiation dose and V30 between regular and restricted groups (P > 0.05), but lower V20 and higher V45 were determined in the restricted group (P < 0.05). The mean irradiation dose, V15, V20, and V26 of bilateral parotid ducts were lower in the restricted group as compared to the regular group (P < 0.05). Conclusion. IMRT for NPC can effectively reduce the mean irradiation dose and play a PG stem cell preservation role by giving specific dose limitation conditions to the parotid duct area without affecting PTV dose distribution and OAR irradiation dose, which has certain feasibility. [ABSTRACT FROM AUTHOR]

Investigating whether landmarks and routes affect navigational efficiency and learning transfer in traffic is essential. In this study, a virtual reality-based driving system was employed to determine the effects of landmarks and routes on human neurocognitive behavior. The participants made four (4) journeys to predetermined destinations. They were provided with different landmarks and routes to aid in reaching their respective destinations. We considered two (2) groups and conducted two (2) sessions per group in this study. Each group had sufficient and insufficient landmarks. We hypothesized that using insufficient landmarks would elicit an increase in psychophysiological activation, such as increased heart rate, eye gaze, and pupil size, which would cause participants to make more errors. Moreover, easy and difficult routes elicited different cognitive workloads. Thus, a high cognitive load would negatively affect the participants when trying to apply the knowledge acquired at the beginning of the exercise. In addition, the navigational efficiency of routes with sufficient landmarks was remarkably higher than that of routes with insufficient landmarks. We evaluated the effects of landmarks and routes by assessing the recorded information of the drivers' pupil size, heart rate, and driving performance data. An analytical strategy, several machine learning algorithms, and data fusion methods have been employed to measure the neurocognitive load of each participant for user classification. The results showed that insufficient landmarks and difficult routes increased pupil size and heart rate, which caused the participants to make more errors. The results also indicated that easy routes with sufficient landmarks were deemed more efficient for navigation, where users' cognitive loads were much lower than those with insufficient landmarks and difficult routes. The high cognitive workload hindered the participants when trying to apply the knowledge acquired at the beginning of the exercise. Meanwhile, the data fusion method achieved higher accuracy than the other classification methods. The results of this study will help improve the use of landmarks and design of driving routes, as well as paving the way to analyze traffic safety using the drivers' cognition and performance data. [ABSTRACT FROM AUTHOR]

A Cu–N-doped carbon nanotube with an unsaturated coordination Cu atom (Cu–N3) was fabricated and it exhibited over 90% CO faradaic efficiency (FE) in a wide potential range from −0.42 to −0.92 V. The maximum CO FE can reach 98.7% with a high CO partial current density of 234.3 mA cm−2 in a flow cell. Theoretical calculations elucidated that the Cu–N3 site facilitated the formation of COOH*, thereby accelerating the CO2 electrochemical reduction. [ABSTRACT FROM AUTHOR]

Oxidation of Mn(II) and the subsequent mineral mineralization can significantly influence the transport and fate of trace metals and organic pollutants in the soil and sediment environments. Abiotic oxidation of Mn(II) on the surface of Fe mineral in the open air is a vital formation pathway of Mn (oxyhydr)oxides; however, the impact of electron shuttle substances at neutral pH has seldomly been reported. Anthraquinone-2, 6-disulfonate (AQDS) is a typical electron shuttle and might affect the abiotic oxidation of Mn(II). In this study, abiotic oxidation of Mn(II) on the surface of a hematite substrate and mineralization of oxidation product in the presence of AQDS (0–1 mM) were investigated at pH 7.5 in the open air. In the Mn(II)-AQDS treatments, most Mn(II) remained in solution, suggesting that AQDS shows little catalytic activity in the abiotic oxidation of Mn(II) without hematite present. By contrast, Mn(II) was rapidly oxidized, and oxidation rates increased from 4.2 × 10−2 to 8.8 × 10−2 h−1 with increasing AQDS concentration from 0 to 1 mM in the hematite-Mn(II)-AQDS treatments. Abiotic oxidation of Mn(II) produced granular-like Mn 3 O 4 , fibrous-like β-MnOOH, and rod-like γ-MnOOH, and no other secondary Fe minerals were found. The proposed mechanism of the AQDS-mediated abiotic oxidation of Mn(II) on a hematite surface is the AQDS serving as an electronic medium with semiconductor hematite as a foreign substrate, promoting electron transfer between oxygen and Mn(II) on its surface. Our results revealed that electron mediators impart crucial control on not only the rate but also the compositions of Mn(II) oxidation product. The findings of this study provide new insights into the geochemical functions of electron shuttles on the dynamics of redox-sensitive elements under oxic and neutral conditions and expand the understanding of interfacial heterogeneous nucleation reactions at the molecular scale. • AQDS promoted the kinetic of Mn(II) abiotic oxidation on the surface of hematite. • Mn(II) oxidation products were composed of Mn 3 O 4 , γ-MnOOH, and β-MnOOH. • High concentration of AQDS facilitated the formation of Mn(III) mineral. • Mechanism of AQDS-mediated Mn(II) oxidation on hematite surface was proposed. [ABSTRACT FROM AUTHOR]

Vanadate materials are feasible cathodes for metal–ion batteries due to their stable layered structure, abundant valence states, and high capacity. However, much uncertainty still exists about precisely modulating intercalants to facilitate ion storage. Here, V2O5 pre‐intercalated with various transition metal ions M2+ (M═Ni, Co, Mn) are developed as model materials to analyze the coupling effect between guest ions and host material. Through density functional theory simulations, it is found that M2+ interacts with V–O chain via M 3d‐O 2p covalent bonds, and extended X‐ray absorption fine structure reveals the Ni─O interatomic distance at 1.56 Å shorter than Co─O (1.60 Å) and Mn─O (1.72 Å), suggesting the M–O band type with different covalency degree can optimize VOx polyhedron and local electronic structure. Furthermore, NiVO cathode materials with the smallest layer spacing shows higher redox voltage and better rate/cycling performance for Ca2+ storage than CoVO/MnVO, elucidating that Ni has stronger tendency to attract electrons and bonds with V–O layer tightly, thus supplying a reliable ion diffusion channel for Ca2+. Through ions pre‐intercalated techniques, this work highlights both layer spacing and physicochemical properties of intercalants affect electrochemical process, which is significant for developing high‐performance vanadate cathode materials. [ABSTRACT FROM AUTHOR]

Different B 2 O 3 content was added to Ce3+–doped Gd 2 O 3 –Al 2 O 3 –SiO 2 (xBGAS:1.1Ce3+, x = 0, 5, 10, 15) glasses to improve the photoluminescence (PL) and scintillation properties. The transmittance of 15BGAS:1.1Ce3+ glass is over 80%. The X–ray absorption near edge spectroscopy (XANES) spectra imply that Ce4+ can be effectively reduced to Ce3+ in the glasses by adding Si 3 N 4. The excitation and emission spectra show a blue shift with increase of B 2 O 3 content. The photoluminescence quantum yield (PL QY) increases with the increase of B 2 O 3 content, reached the maximum of 59.55% when x = 15. The PL decay time of the glasses exhibits typical values (44–50 ns) due to 5d→4f transition of Ce3+ ions. The PL thermal activation energy become larger, indicating that xBGAS:1.1Ce3+ glasses have better luminescent thermal stability. The integral X–ray excited luminescence (XEL) intensity of the 15BGAS:1.1Ce3+ glass is 37.38% of Bi 4 Ge 3 O 12 (BGO) crystal, and the light yield is 1267 ph/MeV with an energy resolution of 23.22% at 662 keV when exposed to γ–rays. With the increase of B 2 O 3 content, the fast component of scintillation decay time gradually becomes shorter and the slow component becomes longer. The thermally stimulated luminescence (TSL) curves were measured to investigate the trap depth and density of defects in xBGAS:1.1Ce3+ glasses. [ABSTRACT FROM AUTHOR]

The abiotic reactions of Fe(II) oxidation and nitrite (NO 2 –) reduction (chemodenitrification) are a vital geochemical processes at the interface of anoxic sediments and water. Chemodenitrification leads to the formation of secondary iron (Fe)-bearing minerals, which can influence the dynamic behavior of arsenate (As(V)). However, the coupled mechanism and pH effect of chemodenitrification and As(V) sequestration are not well understood. Here, immobilization of As(V) was investigated at pH 5.5, 6.5, and 8.0 during chemodenitrification. Kinetics of 9 mM Fe(II) oxidation and 3 mM nitrite reduction increased with increasing pH but decreased in the presence of 0.5 mM As(V). The results of X-ray diffraction and linear combination fitting of the Fe K-edge EXAFS spectra together showed that high pH and low As(V) were favorable for the formation of secondary crystalline Fe oxides, such as lath-like lepidocrocite, rod-like goethite, and nano-magnetite. Despite efficient removal, the retention of As(V) species on the newly-formed secondary Fe minerals varied substantially at different pH values. Microscopic and spectroscopic analyses at nano- and molecular-scales revealed that As(V) was mainly adsorbed onto poorly crystalline Fe minerals at pH 5.5, while it was partially incorporated into the lattice structure of crystalline Fe minerals through isomorphic substitution at pH 6.5 and 8.0. The amount of As(V) sequestration was positively correlated with newly-formed crystalline Fe minerals. A model was established by integrating Fe mineral transformation and nonlinear As(V) binding to various Fe minerals, which could accurately predict distribution of adsorbed As(V). The pH increase during chemodenitrification promoted immobilization of As(V) in newly-formed crystalline Fe minerals. The findings on pH-dependent chemodenitrification with As have significant implications for understanding the long-term solubility and migration of As(V), and could provide a potential strategy for As immobilization in sediments. [ABSTRACT FROM AUTHOR]

Machine learning models often converge slowly and are unstable due to the significant variance of random data when using a sample estimate gradient in SGD. To increase the speed of convergence and improve stability, a distributed SGD algorithm based on variance reduction, named DisSAGD, is proposed in this study. DisSAGD corrects the gradient estimate for each iteration by using the gradient variance of historical iterations without full gradient computation or additional storage, i.e., it reduces the mean variance of historical gradients in order to reduce the error in updating parameters. We implemented DisSAGD in distributed clusters in order to train a machine learning model by sharing parameters among nodes using an asynchronous communication protocol. We also propose an adaptive learning rate strategy, as well as a sampling strategy, to address the update lag of the overall parameter distribution, which helps to improve the convergence speed when the parameters deviate from the optimal value—when one working node is faster than another, this node will have more time to compute the local gradient and sample more samples for the next iteration. Our experiments demonstrate that DisSAGD significantly reduces waiting times during loop iterations and improves convergence speed when compared to traditional methods, and that our method can achieve speed increases for distributed clusters. [ABSTRACT FROM AUTHOR]

Pt cocatalyst play bifunctions in the photoreforming of polyethylene terephthalate plastic waste by improving the charge transfer kinetics and regulating the adsorption-desorption of oxidation intermediates, thereby achieving efficient photocatalytic H 2 evolution rate and producing valuable commodities in the photoreforming reactions. [Display omitted] Upcycle polyethylene terephthalate (PET) waste by photoreforming (PR) is a sustainable and green approach to tackle environmental problems but with challenges to obtain valuable oxidation products and high purity hydrogen simultaneously. Noble metal cocatalysts are essential to enhance the overall PR reaction efficacy. In this work, TiO 2 nanotubes (TiO 2 NTs) decorated with single Pt atoms (Pt 1 /TiO 2) or Pt nanoparticles (Pt NPs /TiO 2) are used in the photoreforming reaction (in one batch), and the oxidation products from ethylene glycol (EG, hydrolysed product of PET) in liquid phase and hydrogen are detected. With Pt 1 /TiO 2 , EG is oxidized to glyoxal, glyoxylate or lactate, and hydrogen evolution rate (r H 2) reaches 51.8 μmol⋅h−1⋅g cat −1, that is 30 times higher than that of TiO 2. For Pt NPs /TiO 2 (size of Pt NPs: 1.97 nm), hydrogen evolution reaches 219.1 μmol⋅h−1⋅g cat −1, but with the oxidation product of acetate only. DFT calculation demonstrates that for Pt NPs, the reaction path for hydrogen evolution is preferred thermodynamically, due to the formation of Schottky junction. On the oxidation of EG, theoretical and spectroscopic analysis suggest that bidentate adsorption of EG at the interface is facile on Pt 1 /TiO 2 , compared to that on Pt NPs /TiO 2 (two Pt sites), but oxidation products, adsorb less strongly, compared to Pt NPs /TiO 2 , that eventually regulates the distribution of oxidation products. The results thus demonstrate the bifunctions of Pt in the PR reaction, i.e., electron transfer mediator for hydrogen evolution and reactive sites for molecules adsorption. The oxidation reaction is dominated by the adsorption-desorption behavior of molecules but the reduction reaction is controlled by the electron transfer. In addition, acidification of pretreated PET alkaline solution achieves separation of pure terephthalic acid (PTA), which further improves the reaction efficiency possibly by offering high density of active sites and acidic environment. Our work thus demonstrates that to upcycle PET plastics, an optimized process can be reached by atomic design of photocatalysts and proper treatment on the plastic wastes. [ABSTRACT FROM AUTHOR]

In aqueous aluminum‐ion batteries (AAIBs), the insertion/extraction chemistry of Al3+ often leads to poor kinetics, whereas the rapid diffusion kinetics of hydronium ions (H3O+) may offer the solution. However, the presence of considerable Al3+ in the electrolyte hinders the insertion reaction of H3O+. Herein, we report how oxygen‐deficient α‐MoO3 nanosheets unlock selective H3O+ insertion in a mild aluminum‐ion electrolyte. The abundant oxygen defects impede the insertion of Al3+ due to excessively strong adsorption, while allowing H3O+ to be inserted/diffused through the Grotthuss proton conduction mechanism. This research advances our understanding of the mechanism behind selective H3O+ insertion in mild electrolytes. [ABSTRACT FROM AUTHOR]

In aqueous aluminum‐ion batteries (AAIBs), the insertion/extraction chemistry of Al3+ often leads to poor kinetics, whereas the rapid diffusion kinetics of hydronium ions (H3O+) may offer the solution. However, the presence of considerable Al3+ in the electrolyte hinders the insertion reaction of H3O+. Herein, we report how oxygen‐deficient α‐MoO3 nanosheets unlock selective H3O+ insertion in a mild aluminum‐ion electrolyte. The abundant oxygen defects impede the insertion of Al3+ due to excessively strong adsorption, while allowing H3O+ to be inserted/diffused through the Grotthuss proton conduction mechanism. This research advances our understanding of the mechanism behind selective H3O+ insertion in mild electrolytes. [ABSTRACT FROM AUTHOR]

Emerging step‐scheme (S‐scheme) heterostructures hold unique superiority in steering directional charge transport and reinforcing redox capacity, yet rational modification of S‐scheme heterostructures by single atoms (SAs) for efficient photocatalytic H2 evolution is rarely reported. In this work, Pd SAs‐modulated organic–inorganic g‐C3N4/CdS S‐scheme heterostructures are designed and prepared by a one‐pot mechanochemical approach allowing for g‐C3N4 nanosheets/CdS nanoparticles to confine atomically dispersed Pd co‐catalysts. The g‐C3N4/CdS S‐scheme charge‐transfer pathway is corroborated by a combination of in situ irradiated X‐ray photoelectron spectroscopy, electron paramagnetic resonance, and Kelvin probe force microscopy. Density functional theory (DFT) calculations, high‐angle annular dark‐field scanning transmission electron microscopy, and X‐ray absorption fine structure identify Pd‐S3 and Pd‐N2 atomic moieties underpinned by the electronic interaction between Pd SAs and g‐C3N4/CdS heterostructures, in which the d‐band center of Pd SAs is optimized for proton adsorption thermodynamically. Further, the g‐C3N4/CdS S‐scheme heterostructures alongside Pd SAs in concert boost the rapid migration of photogenerated electrons (1.05 ps) via Pd─S and Pd─N bond‐derived channels. A maximal H2 evolution rate of 85.66 mmol h−1 g−1 is achieved by 1 wt% Pd‐20 wt% g‐C3N4/CdS hierarchical composites. This work may guide the design of high‐efficiency S‐scheme‐based photocatalysts for solar‐to‐H2 conversion and beyond. [ABSTRACT FROM AUTHOR]

The electrooxidation of urea holds great potential for converting urea from wastewater into hydrogen, contributing to environmental protection and sustainable energy production. This necessitates the development of highly efficient and stable catalysts for the urea oxidation reaction (UOR). In this study, a NiCoCr‐LDH/NF (nickel‐cobalt‐chromium layered double hydroxide/nickel foam) electrode is successfully synthesized via a simple hydrothermal method, demonstrating excellent electrocatalytic performance with a low work potential of 1.38 V at a high current density of 100 mA cm−2. In situ, Raman spectra analysis revealed that the incorporation of chromium (Cr) facilitated the generation of active γ‐NiOOH species and catalyst reconstruction. Density functional theory (DFT) simulations confirmed that the lower formation energy of γ‐NiOOH is due to the weakened interaction of O─H bonds because of a narrow energy range of hybridization between O‐2pz orbitals and H‐1s orbitals. The introduction of Cr also improved the adsorption energy of urea molecules and its intermediates, thereby enhancing the overall activity of UOR. With its excellent electrocatalytic performance, unique electronic states, and coordination structures, the NiCoCr‐LDH/NF electrode showcases great potential for practical applications in the field of energy catalysis. [ABSTRACT FROM AUTHOR]

High-content atomically distributed W(V , VI) coordinated with O atoms as WO2 moieties anchored on FeCo layered double hydroxide (FeCo LDH) nanosheets in the structure of SAC W–FeCo LDH is obtained by a facile coprecipitation method, and it presented clearly enhanced stable OER electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Energy‐saving and value‐added management in advanced catalysis is highly desirable but is challenged by the limitations of multifunctional catalysts and catalytic modules. Herein, an azo‐linked phthalocyanine‐porphyrin covalent organic framework (COF) with the ultrathin layered nanostructure grown on carbon nanotubes (NiPc‐azo‐H2Pp@CNTs) has been designed and synthesized, which can serve as a highly active and stable bifunctional heterojunction electrocatalyst for selective paired‐electrosynthesis through coupling anodic iodide oxidation reaction and cathodic CO2 conversion. Particularly, the inbuilt local microenvironment conferred by the dihydroporphyrin moieties in COF can act as a proton reservoir to promote the proton relay at the heterojunction interface during the electrocatalytic process. Moreover, through the cascade construction of dual electrocatalytic/organocatalytic modules, the cathode‐generated CO can be further converted to dimethyl carbonate with a yield of 6.21 mmol L−1 h−1, while the anode‐produced iodine can be derived into iodoform on the hundred‐milligram scale. It is worth noting that the value‐added cascade synthesis mediated by paired‐electrolysis using the distinctive and high‐powered electrocatalysts will help advance the sustainable development of industrial intelligent manufacturing. [ABSTRACT FROM AUTHOR]

Engineering isolated metal sites resembling the primary coordination sphere of metallocofactors enables atomically dispersed materials as promising nanozymes. However, most existing nanozymes primarily focus on replicating specific metallocofactors while neglecting other supporting cofactors within active pockets, leading to reduced electron transfer (ET) efficiency and thus inferior catalytic performances. Herein, we report a metal–organic framework UiO‐67 nanozyme with atomically dispersed iron sites, which involves multiple tailored enzyme‐like nanocofactors that synergistically drive the ET process for enhanced peroxidase‐like catalysis. Among them, the linker‐coupled atomic iron site plays a critical role in substrate activation, while bare linkers and zirconia nodes facilitate the ET efficiency of intermediates. The synergy of three nanocofactors results in a 4.29‐fold enhancement compared with the single effort of isolated metal site‐based nanocofactor, holding promise in immunoassay for sensitive detection of chlorpyrifos. This finding opens a new way for designing high‐performance nanozymes by harmonizing various nanocofactors at the atomic and molecular scale. [ABSTRACT FROM AUTHOR]

Engineering isolated metal sites resembling the primary coordination sphere of metallocofactors enables atomically dispersed materials as promising nanozymes. However, most existing nanozymes primarily focus on replicating specific metallocofactors while neglecting other supporting cofactors within active pockets, leading to reduced electron transfer (ET) efficiency and thus inferior catalytic performances. Herein, we report a metal–organic framework UiO‐67 nanozyme with atomically dispersed iron sites, which involves multiple tailored enzyme‐like nanocofactors that synergistically drive the ET process for enhanced peroxidase‐like catalysis. Among them, the linker‐coupled atomic iron site plays a critical role in substrate activation, while bare linkers and zirconia nodes facilitate the ET efficiency of intermediates. The synergy of three nanocofactors results in a 4.29‐fold enhancement compared with the single effort of isolated metal site‐based nanocofactor, holding promise in immunoassay for sensitive detection of chlorpyrifos. This finding opens a new way for designing high‐performance nanozymes by harmonizing various nanocofactors at the atomic and molecular scale. [ABSTRACT FROM AUTHOR]

Understanding the correlation between the structural evolution of electrocatalysts and their catalytic activity is both essential and challenging. In this study, we investigate this correlation in the context of the oxygen evolution reaction (OER) by examining the influence of structural disorder during and after dynamic structural evolution on the OER activity of Fe−Ni (oxy)hydroxide catalysts using operando X‐ray absorption spectroscopy, alongside other experiments and theoretical calculations. The Debye–Waller factors obtained from extended X‐ray absorption fine structure analyses reflect the degree of structural disorder and exhibit a robust correlation with the intrinsic OER activities of the electrocatalysts. The enhanced OER activity of in situ‐generated metal (oxy)hydroxides derived from different pre‐catalysts is linked to increased structural disorder, offering a promising approach for designing efficient OER electrocatalysts. This strategy may inspire similar investigations in related electrocatalytic energy‐conversion systems. [ABSTRACT FROM AUTHOR]

Understanding the correlation between the structural evolution of electrocatalysts and their catalytic activity is both essential and challenging. In this study, we investigate this correlation in the context of the oxygen evolution reaction (OER) by examining the influence of structural disorder during and after dynamic structural evolution on the OER activity of Fe−Ni (oxy)hydroxide catalysts using operando X‐ray absorption spectroscopy, alongside other experiments and theoretical calculations. The Debye–Waller factors obtained from extended X‐ray absorption fine structure analyses reflect the degree of structural disorder and exhibit a robust correlation with the intrinsic OER activities of the electrocatalysts. The enhanced OER activity of in situ‐generated metal (oxy)hydroxides derived from different pre‐catalysts is linked to increased structural disorder, offering a promising approach for designing efficient OER electrocatalysts. This strategy may inspire similar investigations in related electrocatalytic energy‐conversion systems. [ABSTRACT FROM AUTHOR]

Single‐atom alloys (SAAs) have ignited a surge of unprecedented interest as the advanced nanomaterials and opened many opportunities for wide applications. Herein, 3D porous aerogels comprising ionic liquid (IL) functionalized PdBi SAA building blocks with atomically dispersed Bi on Pd nanowires (IL/Pd50Bi1) are synthesized with accelerated gelation kinetics, which could serve as high‐efficiency electrocatalysts for ethanol oxidation reaction (EOR). Benefiting from the unique structures of aerogels including synergistic effects of PdBi SAA nanowire networks and interface engineering, the optimized IL/Pd50Bi1 aerogels display a nearly fourfold enhancement in mass activity and boosted stability for EOR compared to commercial Pd/C. Density functional theory calculations further demonstrate that isolated Bi atoms on Pd nanowire networks decrease the energy barrier of the rate‐determining step, resulting in excellent electrocatalytic activity for EOR. This work provides a promising method for developing efficient SAA catalysts for fuel electrooxidation. [ABSTRACT FROM AUTHOR]

Renewable energy conversion and storage are crucial in aiding the worldwide efforts to replace fossil fuels and achieve carbon neutrality. In particular, electrocatalytic water splitting to obtain H2 and CO2 reduction to high‐value‐added fuels can lead to an epoch of hydrogen energy and a closed‐loop carbon cycle. Although many reported electrocatalysts have demonstrated outstanding performance at the laboratory scale, the origin of the superior electrocatalytic activity and selectivity and the structural evolution of these catalysts remain ambiguous. For this purpose, operando techniques are able to combine the characterizations of the catalyst with measurement of its performance under real working conditions. Herein, a critical overview of recent developments in understanding the underlying mechanisms of water splitting and CO2 reduction is presented, emphasizing the advanced operando X‐ray absorption spectroscopy characterization of these two electrocatalytic reactions. Some perceptions of the rising X‐ray technique directions and the foreground in this field are also presented. [ABSTRACT FROM AUTHOR]

Calcium ion batteries (CIBs) are considered as an important candidate for post‐lithium energy storage devices due to their abundance of resources and low cost. However, CIBs still suffer from slow kinetics due to the large solvation structure and high desolvation energy of Ca2+ ions. Here, a solvation regulation strategy based on donor number (DN) is reported to achieve easy‐desolvation and rapid storage of Ca2+ in sodium vanadate (Na2V6O16·2H2O, NVO). Specially, the solvent with a low DN, represented by propylene carbonate (PC), forms the first solvation shell of calcium ions with weak binding energy and small shell structure, which facilitates the migration of Ca2+ in the electrolyte. More importantly, the low DN solvent is preferentially desolvated at the cathode/electrolyte interface, promoting the insertion of Ca2+ into the NVO electrode. Mechanism studies further confirm the highly reversible uptake/release of Ca2+ in the NVO cathode, along with the VO distance change in the coordination structure. Therefore, the NVO cathode achieves high capacity (376 mAh g−1 at 0.3 A g−1) and high‐rate performance (151 mAh g−1 at 5 A g−1). The weak solvation effect strategy further improves the electrochemical performance and provides great importance for the design of the long‐term development of CIBs. [ABSTRACT FROM AUTHOR]

Compensating the irreversible loss of limited active lithium (Li) is essentially important for improving the energy‐density and cycle‐life of practical Li‐ion battery full‐cell, especially after employing high‐capacity but low initial coulombic efficiency anode candidates. Introducing prelithiation agent can provide additional Li source for such compensation. Herein, we precisely implant trace Co (extracted from transition metal oxide) into the Li site of Li2O, obtaining (Li0.66Co0.11□0.23)2O (CLO) cathode prelithiation agent. The synergistic formation of Li vacancies and Co‐derived catalysis efficiently enhance the inherent conductivity and weaken the Li−O interaction of Li2O, which facilitates its anionic oxidation to peroxo/superoxo species and gaseous O2, achieving 1642.7 mAh/g~Li2O prelithiation capacity (≈980 mAh/g for prelithiation agent). Coupled 6.5 wt % CLO‐based prelithiation agent with LiCoO2 cathode, substantial additional Li source stored within CLO is efficiently released to compensate the Li consumption on the SiO/C anode, achieving 270 Wh/kg pouch‐type full‐cell with 92 % capacity retention after 1000 cycles. [ABSTRACT FROM AUTHOR]

Compensating the irreversible loss of limited active lithium (Li) is essentially important for improving the energy‐density and cycle‐life of practical Li‐ion battery full‐cell, especially after employing high‐capacity but low initial coulombic efficiency anode candidates. Introducing prelithiation agent can provide additional Li source for such compensation. Herein, we precisely implant trace Co (extracted from transition metal oxide) into the Li site of Li2O, obtaining (Li0.66Co0.11□0.23)2O (CLO) cathode prelithiation agent. The synergistic formation of Li vacancies and Co‐derived catalysis efficiently enhance the inherent conductivity and weaken the Li−O interaction of Li2O, which facilitates its anionic oxidation to peroxo/superoxo species and gaseous O2, achieving 1642.7 mAh/g~Li2O prelithiation capacity (≈980 mAh/g for prelithiation agent). Coupled 6.5 wt % CLO‐based prelithiation agent with LiCoO2 cathode, substantial additional Li source stored within CLO is efficiently released to compensate the Li consumption on the SiO/C anode, achieving 270 Wh/kg pouch‐type full‐cell with 92 % capacity retention after 1000 cycles. [ABSTRACT FROM AUTHOR]

Copper oxide-based materials show promising activity in biomass electrooxidation. However, systematic study of active sites evolution under electrochemical condition was rarely studied. In this work, we report copper oxide undergoes potential-dependent structure evolution with successive formation of Cu(OH) 2 and CuOOH, which exhibit distinct activities in electrocatalytic glucose oxidation. [Display omitted] Electrocatalytic oxidation of renewable biomass (such as glucose) into high-value-added chemicals provides an effective approach to achieving carbon neutrality. CuO-derived materials are among the most promising electrocatalysts for biomass electrooxidation, but the identification of their active sites under electrochemical conditions remains elusive. Herein, we report a potential-dependent structure evolution over CuO in the glucose oxidation reaction (GOR). Through systematic electrochemical and spectroscopic characterizations, we unveil that CuO undergoes Cu2+/Cu+ and Cu3+/Cu2+ redox processes at increased potentials with successive generation of Cu(OH) 2 and CuOOH as the active phases. In addition, these two structures have distinct activities in the GOR, with Cu(OH) 2 being favorable for aldehyde oxidation, and CuOOH showed faster kinetics in carbon–carbon cleavage and alcohol/aldehyde oxidation. This work deepens our understanding of the dynamic reconstruction of Cu-based catalysts under electrochemical conditions and may guide rational material design for biomass valorization. [ABSTRACT FROM AUTHOR]

Exploring efficient transition-metal-based electrocatalysts for oxygen evolution reaction (OER) is imperative but remain challenging for sustainable energy storage and conversion systems. Foreign species doping is a significant regulation strategy to enhance the intrinsic activity of host matrix. However, the potential relationship of structure-activity caused by guest doping elements is seldom tracked systematically. In this case, both theoretical screening and experimental verification are complementarily employed to investigate the guest doping effects of ten first-row transition metals (Sc~Zn) on bimetallic NiCo layered double hydroxide (NiCo-LDH). As a result, the optimized Fe-doped NiCo-LDH is identified as the most promising candidate toward alkaline electrocatalytic OER, which exhibits the quasi-industrial current density of 1000 mA cm-2 at overpotential of400 mV. Meanwhile, it also shows impressively long-term stability of 500 h at 500 mA cm-2 with a negligible activity loss. Moreover, in situ electrochemical Raman spectroscopy unveils the dynamic structure evolution from pre-catalytic state (Fe-NiCo-LDH) to metal oxyhydroxide (Fe-(NiCo)OOH) during the oxidation reaction, and ab-initio molecular dynamics simulations are further performed to confirm the thermodynamic stability of activated Fe-(NiCo)OOH phase. This work provides a promising platform for exploring the critical role of transition metal guest doping on host matrix in developing industrially required OER electrocatalysts. [ABSTRACT FROM AUTHOR]

The key issue in the 5‐hydroxymethylfurfural oxidation reaction (HMFOR) is to understand the synergistic mechanism involving the protons deintercalation of catalyst and the adsorption of the substrate. In this study, a Pd/NiCo catalyst was fabricated by modifying Pd clusters onto a Co‐doped Ni(OH)2 support, in which the introduction of Co induced lattice distortion and optimized the energy band structure of Ni sites, while the Pd clusters with an average size of 1.96 nm exhibited electronic interactions with NiCo support, resulting in electron transfer from Pd to Ni sites. The resulting Pd/NiCo exhibited low onset potential of 1.32 V and achieved a current density of 50 mA/cm2 at only 1.38 V. Compared to unmodified Ni(OH)2, the Pd/NiCo achieved an 8.3‐fold increase in peak current density. DFT calculations and in situ XAFS revealed that the Co sites affected the conformation and band structure of neighboring Ni sites through CoO6 octahedral distortion, reducing the proton deintercalation potential of Pd/NiCo and promoting the production of Ni3+−O active species accordingly. The involvement of Pd decreased the electronic transfer impedance, and thereby accelerated Ni3+−O formation. Moreover, the Pd clusters enhanced the adsorption of HMF through orbital hybridization, kinetically promoting the contact and reaction of HMF with Ni3+−O. [ABSTRACT FROM AUTHOR]

Highlights: Oxygen-coordinated single-atom Mn catalyst was fabricated via introducing oxygen functional groups rich bacterial cellulose as the adsorption regulator through a combined impregnation–pyrolysis–etching synthetic route. Mn–O–C as the electrocatalyst exhibits superior electrocatalytic activity toward ammonia synthesis with a maximum NH3 yield rate of 1476.9 ± 62.6 μg h−1 cm−2 at − 0.7 V (vs. RHE) and a faradaic efficiency of 89.0 ± 3.8% at − 0.5 V (vs. RHE) under ambient conditions. Electrocatalytic mechanism of Mn–(O–C2)4 site for nitrate reduction reaction is unveiled by a combination of in situ spectroscopy characterization and computational study. Electrocatalytic nitrate reduction reaction has attracted increasing attention due to its goal of low carbon emission and environmental protection. Here, we report an efficient NitRR catalyst composed of single Mn sites with atomically dispersed oxygen (O) coordination on bacterial cellulose-converted graphitic carbon (Mn–O–C). Evidence of the atomically dispersed Mn–(O–C2)4 moieties embedding in the exposed basal plane of carbon surface is confirmed by X-ray absorption spectroscopy. As a result, the as-synthesized Mn–O–C catalyst exhibits superior NitRR activity with an NH3 yield rate (RNH3) of 1476.9 ± 62.6 μg h−1 cm−2 at − 0.7 V (vs. reversible hydrogen electrode, RHE) and a faradaic efficiency (FE) of 89.0 ± 3.8% at − 0.5 V (vs. RHE) under ambient conditions. Further, when evaluated with a practical flow cell, Mn–O–C shows a high RNH3 of 3706.7 ± 552.0 μg h−1 cm−2 at a current density of 100 mA cm−2, 2.5 times of that in the H cell. The in situ FT-IR and Raman spectroscopic studies combined with theoretical calculations indicate that the Mn–(O–C2)4 sites not only effectively inhibit the competitive hydrogen evolution reaction, but also greatly promote the adsorption and activation of nitrate (NO3−), thus boosting both the FE and selectivity of NH3 over Mn–(O–C2)4 sites. [ABSTRACT FROM AUTHOR]

The key issue in the 5‐hydroxymethylfurfural oxidation reaction (HMFOR) is to understand the synergistic mechanism involving the protons deintercalation of catalyst and the adsorption of the substrate. In this study, a Pd/NiCo catalyst was fabricated by modifying Pd clusters onto a Co‐doped Ni(OH)2 support, in which the introduction of Co induced lattice distortion and optimized the energy band structure of Ni sites, while the Pd clusters with an average size of 1.96 nm exhibited electronic interactions with NiCo support, resulting in electron transfer from Pd to Ni sites. The resulting Pd/NiCo exhibited low onset potential of 1.32 V and achieved a current density of 50 mA/cm2 at only 1.38 V. Compared to unmodified Ni(OH)2, the Pd/NiCo achieved an 8.3‐fold increase in peak current density. DFT calculations and in situ XAFS revealed that the Co sites affected the conformation and band structure of neighboring Ni sites through CoO6 octahedral distortion, reducing the proton deintercalation potential of Pd/NiCo and promoting the production of Ni3+−O active species accordingly. The involvement of Pd decreased the electronic transfer impedance, and thereby accelerated Ni3+−O formation. Moreover, the Pd clusters enhanced the adsorption of HMF through orbital hybridization, kinetically promoting the contact and reaction of HMF with Ni3+−O. [ABSTRACT FROM AUTHOR]

Recently, nanozyme-based sensing platforms have attracted widespread attention due to their excellent performance in practical applications. In this paper, phosphorus-doped porous materials were synthesized by a one-step method and metal-doped with different metal salts. The results show that the iron-containing porous nitrogen-phosphorus material (FeNPC) has the best peroxidase activity. FeNPC catalyzes hydrogen peroxide to generate hydroxyl radical (•OH) which oxidizes colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxTMB. When the above system encounters ferulic acid, the blue product will be inhibited, and the color of the reaction solution will change, so ferulic acid can be detected by the colorimetric method. Ferulic acid is an antioxidant used in humans as an antibacterial and antiviral drug. The detection limit of this colorimetric sensor is as low as 1.3 nM. Compared with other detection methods, the colorimetric method is simple, fast, and cheap and has a good development prospect. [ABSTRACT FROM AUTHOR]

Great efforts are exploring single-atom (SA) sites for tailoring catalytic effects on the sulfur-related redox reaction in Li-S battery, while edge-distributed SA sites lack attention. Herein, we implanted SA iron sites in N-doped porous carbon on CNTs (Fe-NPC@CNTs) to obtain edge-distributed FeN 4 moieties via a polymer inductive strategy. The Fe-NPC@CNTs own enhanced "trapping-conversion" ability for polysulfides. The Li-S battery based on Fe-NPC@CNTs achieves a wonderful capacity of 1004 mAh g−1 at 1 C with long-term cycling stability, where the capacity fading rate is 0.032% per cycle over 1200 cycles. Noteworthy, the cell delivers very large capacities of 3.94/6.12 mAh cm−2 under high sulfur loadings of 4.50/5.04 mg cm−2 at 0.5/0.2 C, corresponding to 82.5/82.4% capacity retentions over 100 cycles. Under ultrahigh sulfur loadings (7.8/10.9 mg cm−2), the cell exhibits amazing large areal capacities of 7.63/10.76 mAh cm−2. The edge-distributed SA sites engineering provides a bright blueprint for advanced Li-S battery. [Display omitted] • Fe-NPC@CNTs has highly exposed edge-distributed Fe-N 4 moieties. • Charge redistribution of Fe atoms is found for Fe-NPC@CNTs. • Enhanced "trapping-conversion" property for polysulfides is obtained for Fe-NPC@CNTs. • The Li-S battery employing Fe-NPC@CNTs demonstrates outstanding performance. [ABSTRACT FROM AUTHOR]

Carbonylation of ethanol with CO2 as carbonyl source into value‐added esters is of considerable significance and interest, while remains of great challenge due to the harsh conditions for activation of inert CO2 in that the harsh conditions result in undesired activation of α‐C−H and even cleavage of C−C bond in ethanol to deteriorate the specific activation of O−H bond. Herein, we propose a photo‐thermal cooperative strategy for carbonylation of ethanol with CO2, in which CO2 is activated to reactive CO via photo‐catalysis with the assistance of *H from thermally‐catalyzed dissociation of alcoholic O−H bond. To achieve this proposal, an interfacial site and oxygen vacancy both abundant SrTiCuO3‐x supported Cu2O (Cu2O‐SrTiCuO3‐x) has been designed. A production of up to 320 μmol g−1 h−1 for ethyl formate with a selectivity of 85.6 % to targeted alcoholic O−H activation has been afforded in photo‐thermal assisted gas‐solid process under 3.29 W cm−1 of UV/Vis light irradiation (144 °C) and 0.2 MPa CO2. In the photo‐driven activation of CO2 and following carbonylation, CO2 activation energy decreases to 12.6 kJ mol−1, and the cleavage of alcoholic α‐C−H bond has been suppressed. [ABSTRACT FROM AUTHOR]

Carbonylation of ethanol with CO2 as carbonyl source into value‐added esters is of considerable significance and interest, while remains of great challenge due to the harsh conditions for activation of inert CO2 in that the harsh conditions result in undesired activation of α‐C−H and even cleavage of C−C bond in ethanol to deteriorate the specific activation of O−H bond. Herein, we propose a photo‐thermal cooperative strategy for carbonylation of ethanol with CO2, in which CO2 is activated to reactive CO via photo‐catalysis with the assistance of *H from thermally‐catalyzed dissociation of alcoholic O−H bond. To achieve this proposal, an interfacial site and oxygen vacancy both abundant SrTiCuO3‐x supported Cu2O (Cu2O‐SrTiCuO3‐x) has been designed. A production of up to 320 μmol g−1 h−1 for ethyl formate with a selectivity of 85.6 % to targeted alcoholic O−H activation has been afforded in photo‐thermal assisted gas‐solid process under 3.29 W cm−1 of UV/Vis light irradiation (144 °C) and 0.2 MPa CO2. In the photo‐driven activation of CO2 and following carbonylation, CO2 activation energy decreases to 12.6 kJ mol−1, and the cleavage of alcoholic α‐C−H bond has been suppressed. [ABSTRACT FROM AUTHOR]

The intrinsic poor structural and thermal stability of high‐voltage layered cathodes are aggravated as the charging depth increases, which severely threatens the cycle life and safety of the battery. Herein, without modifying the high‐voltage layered cathode itself, a simple and economic blending strategy is introduced, and an olivine‐LiCoO2 blended cathode featuring superior comprehensive performance (energy, power, cycle‐life, and safety) at 4.65 V is fabricated. The strong bonding affinity at the olivine/LiCoO2 contact interface suppresses lattice O2 release of LiCoO2, thus significantly improving the structural and thermal stability at high delithiation states. Meanwhile, by contacting with high‐electron‐conductivity LiCoO2, the redox activity of olivine is further activated. Therefore, a stable operation of both olivine‐LiCoO2 and olivine‐LiNi0.8Co0.1Mn0.1O2 blended cathode is achieved under harsh cycling conditions (high voltage or elevated temperature) and long‐life pouch‐cell (91.6% capacity retention after 1000 cycles) is harvested, demonstrating the feasibility and universality of this economic blending strategy on heterogenous cathode candidates. [ABSTRACT FROM AUTHOR]

Photocatalytic CO2 reduction (CO2PR) into multi‐carbon products (especially C2H4) is a highly attractive route for global carbon cycle, however, which is seriously limited by sluggish C‐C coupling kinetics and competitive hydrogen evolution reaction (HER) and so on. Herein, the fabrication of a novel supramolecular assembly of NiAl‐Fe‐TCPP is reported by intercalating iron porphyrin (Fe‐TCPP) into NiAl‐layered double hydroxide (NiAl‐LDH), and the resultant NiAl‐Fe‐TCPP exhibit superior catalytic performance on CO2PR to C2H4 under visible light irradiation in presence of photosensitizer. A high C2H4 selectivity up to 93.4% in the carbon‐containing products with the production rate as high as 24.7 µmol h−1 can be achieved over NiAl‐Fe‐TCPP. The ex/in situ X–ray absorption spectoscopy (XAS) indicates that the electron transfer between NiAl‐LDH and Fe‐TCPP can promote the generation of low‐valence of Fe sites, resulting in the efficient production of C2H4. The spin‐polarized density functional theory (DFT) calculations find that the synergistic mechanism that CO2 molecules are activated to CO on NiAl‐LDH and then spilled to Fe‐TCPP and coupled to COCHO#, which is further reduced to C2H4, are feasible in the perspective of Gibbs free energy. Moreover, the strong host‐guest interactions between NiAl‐LDH and Fe‐TCPP lead to the promoted photocatalytic activity and superior cycle stability. [ABSTRACT FROM AUTHOR]

Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is paramount to the energy conversion and storage devices. However, the structural complexity of heterogeneous electrocatalysts makes it a great challenge to elucidate the dynamic structural evolution and OER mechanisms. Here, we develop a controllable atom‐trapping strategy to extract isolated Mo atom from the amorphous MoOx‐decorated CoSe2 (a‐MoOx@CoSe2) pre‐catalyst into Co‐based oxyhydroxide (Mo‐CoOOH) through an ultra‐fast self‐reconstruction process during the OER process. This conceptual advance has been validated by operando characterizations, which reveals that the initially rapid Mo leaching can expedite the dynamic reconstruction of pre‐catalyst, and simultaneously trap Mo species in high oxidation state into the lattice of in situ generated CoOOH support. Impressively, the OER kinetics of CoOOH has been greatly accelerated after the reverse decoration of Mo species, in which the Mo‐CoOOH affords a markedly decreased overpotential of 297 mV at the current density of 100 mA cm−2. Density functional theory (DFT) calculations demonstrate that the Co species have been greatly activated via the effective electron coupling with Mo species in high oxidation state. These findings open new avenues toward directly synthesizing atomically dispersed electrocatalysts for high‐efficiency water splitting. [ABSTRACT FROM AUTHOR]

Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is paramount to the energy conversion and storage devices. However, the structural complexity of heterogeneous electrocatalysts makes it a great challenge to elucidate the dynamic structural evolution and OER mechanisms. Here, we develop a controllable atom‐trapping strategy to extract isolated Mo atom from the amorphous MoOx‐decorated CoSe2 (a‐MoOx@CoSe2) pre‐catalyst into Co‐based oxyhydroxide (Mo‐CoOOH) through an ultra‐fast self‐reconstruction process during the OER process. This conceptual advance has been validated by operando characterizations, which reveals that the initially rapid Mo leaching can expedite the dynamic reconstruction of pre‐catalyst, and simultaneously trap Mo species in high oxidation state into the lattice of in situ generated CoOOH support. Impressively, the OER kinetics of CoOOH has been greatly accelerated after the reverse decoration of Mo species, in which the Mo‐CoOOH affords a markedly decreased overpotential of 297 mV at the current density of 100 mA cm−2. Density functional theory (DFT) calculations demonstrate that the Co species have been greatly activated via the effective electron coupling with Mo species in high oxidation state. These findings open new avenues toward directly synthesizing atomically dispersed electrocatalysts for high‐efficiency water splitting. [ABSTRACT FROM AUTHOR]

Despite lithium‐sulfur (Li‐S) batteries possessing ultrahigh energy density as great promising energy storage devices, the suppressing shuttle effect and improving sulfur redox reaction (SROR) are vital for their practical application. Developing high‐activity electrocatalysts for enhancing the SROR kinetics is a major challenge for the application of Li‐S batteries. Herein, single‐molecule iron phthalocyanine species are anchored on the N and P dual‐doped porous carbon nanosheets (Fe‐NPPC) via axial Fe‐N coordination to optimize the electronic structure of active centers. The Fe‐NPPC can promote the catalytic conversion of polysulfides by modulation of the electronic density in active moieties, endowing the Li‐S battery with a high reversible capacity of 1023 mAh g−1 at 1 C as well as an ultralow capacity decay of 0.035% per cycle over 1500 cycles. Even with a high sulfur loading of 7.1 mg cm−2, the Li‐S battery delivers a high areal capacity of 4.8 mAh cm−2 after 150 cycles at 0.2 C. With further increasing the sulfur loading to 9.2 mg cm−2, an excellent areal capacity of up to 9.3 mAh cm−2 is obtained at 0.1 C. [ABSTRACT FROM AUTHOR]

The self‐reduction of variable valence ions is known to be realized in the specific crystal structure with XO4 groups. It may lead to some outstanding merits for phosphors, such as high thermal stability and easy popularization in industrial production. However, it has never been realized in the host with only planar XO3 anionic groups before. Here, the self‐reduction from Mn4+ to Mn2+ is realized in a borate α‐LiZnBO3, in which the planar triangle [BO3] is the fundamental building unit. The borate‐based phosphor exhibits a typical Mn2+ emission when it is prepared in the ambient atmosphere. The divalent state of doped ions is confirmed via X‐ray absorption fine structure and X‐ray photoelectron spectroscopy. Supported by electron paramagnetic resonance, thermoluminescence, and density functional theory, the oxygen vacancies formed during the synthesis process and the lithium ones introduced by heterovalent substitution are the decisive factors in the valence state‐transition of doped ions. In addition, the low‐valence activators can be stabilized in the lattice to offer the phosphor a good thermal stability of chromaticity coordinates. This study offers a new vision for the self‐reduction system, deepens the understanding of the self‐reduction mechanism, and broadens the choices for developing novel optical functional materials by defect control. [ABSTRACT FROM AUTHOR]

Simultaneously optimizing elementary steps, such as water dissociation, hydroxyl transferring, and hydrogen combination, is crucial yet challenging for achieving efficient hydrogen evolution reaction (HER) in alkaline media. Herein, Ru single atom‐doped WO2 nanoparticles with atomically dispersed Ru–W pair sites (Ru–W/WO2‐800) are developed using a crystalline lattice‐confined strategy, aiming to gain efficient alkaline HER. It is found that Ru–W/WO2‐800 exhibits remarkable HER activity, characterized by a low overpotential (11 mV at 10 mA cm−2), notable mass activity (5863 mA mg−1 Ru at 50 mV), and robust stability (500 h at 250 mA cm−2). The highly efficient activity of Ru–W/WO2‐800 is attributed to the synergistic effect of Ru–W sites through ensemble catalysis. Specifically, the W sites expedite rapid hydroxyl transferring and water dissociation, while the Ru sites accelerate the hydrogen combination process, synergistically facilitating the HER activity. This study opens a promising pathway for tailoring the coordination environment of atomic‐scale catalysts to achieve efficient electro‐catalysis. [ABSTRACT FROM AUTHOR]

Single atom alloy (SAA) catalysts have been recently explored for promotion of various heterogeneous catalysis, but it remains unexplored for selective electrocatalytic reduction of carbon dioxide (CO2) into multi‐carbon (C2+) products involving C−C coupling. Herein we report a single‐atomic Bi decorated Cu alloy (denoted as BiCu‐SAA) electrocatalyst that could effectively modulate selectivity of CO2 reduction into C2+ products instead of previous C1 ones. The BiCu‐SAA catalyst exhibits remarkably superior selectivity of C2+ products with optimal Faradaic efficiency (FE) of 73.4 % compared to the pure copper nanoparticle or Bi nanoparticles‐decorated Cu nanocomposites, and its structure and performance can be well maintained at current density of 400 mA cm−2 under the flow cell system. Based on our in situ characterizations and density functional theory calculations, the BiCu‐SAA is found to favor the activation of CO2 and subsequent C−C coupling during the electrocatalytic reaction, as should be responsible for its extraordinary C2+ selectivity. [ABSTRACT FROM AUTHOR]

Single atom alloy (SAA) catalysts have been recently explored for promotion of various heterogeneous catalysis, but it remains unexplored for selective electrocatalytic reduction of carbon dioxide (CO2) into multi‐carbon (C2+) products involving C−C coupling. Herein we report a single‐atomic Bi decorated Cu alloy (denoted as BiCu‐SAA) electrocatalyst that could effectively modulate selectivity of CO2 reduction into C2+ products instead of previous C1 ones. The BiCu‐SAA catalyst exhibits remarkably superior selectivity of C2+ products with optimal Faradaic efficiency (FE) of 73.4 % compared to the pure copper nanoparticle or Bi nanoparticles‐decorated Cu nanocomposites, and its structure and performance can be well maintained at current density of 400 mA cm−2 under the flow cell system. Based on our in situ characterizations and density functional theory calculations, the BiCu‐SAA is found to favor the activation of CO2 and subsequent C−C coupling during the electrocatalytic reaction, as should be responsible for its extraordinary C2+ selectivity. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are receiving great attention owing to their large theoretical energy density, but the shuttle effect and sluggish kinetic conversion of lithium polysulfides (LiPSs) seriously restrict their practical applications. Herein, various metal single‐atom catalysts immobilized on nitrogen‐doped Ti3C2Tx (M SA/N‐Ti3C2Tx, M = Cu, Co, Ni, Mn, Zn, In, Sn, Pb, and Bi) are successfully prepared by a neoteric vacancy‐assisted strategy, applied as polypropylene (PP) separator coatings to facilitate the fast redox conversion and adsorption of LiPSs for boosting Li–S batteries. Of particular note, among the M SA/N‐Ti3C2Txs, Cu SA/N‐Ti3C2Tx/PP exhibits amazing properties, involving excellent rate performance (925 mAh g−1 at 3 C), superb cycling stability over 1000 cycles, and ultra‐high sulfur utilization even at large sulfur loadings (7.19 mg cm−2; an areal capacity of 5.28 mAh cm−2). X‐ray absorption fine spectroscopy and density functional theory calculations reveal that the asymmetrically coordinated Cu–N1C2 moieties act as the active sites, which possess a higher binding energy and a larger electron cloud with LiPSs than pristine Ti3C2Tx, facilitating the adsorption and kinetic conversion of LiPSs effectively. This work may provide new insights into single atom‐decorated ultrathin 2D materials for enhancing electrochemical performance of advanced batteries for energy storage and conversion. [ABSTRACT FROM AUTHOR]

Understanding the dynamical evolution from metal ions to single atoms is of great importance to the rational development of synthesis strategies for single atom catalysts (SACs) against metal sintering during pyrolysis. Herein, an in situ observation is disclosed that the formation of SACs is ascertained as a two‐step process. There is initially metal sintering into nanoparticles (NPs) (500–600 °C), followed by the conversion of NPs into metal single atoms (Fe, Co, Ni, Cu SAs) at higher temperature (700–800 °C). Theoretical calculations together with control experiments based on Cu unveil that the ion‐to‐NP conversion can arise from the carbon reduction, and NP‐to‐SA conversion being steered by generating more thermodynamically stable Cu‐N4 configuration instead of Cu NPs. Based on the evidenced mechanism, a two‐step pyrolysis strategy to access Cu SACs is developed, which exhibits excellent ORR performance. [ABSTRACT FROM AUTHOR]

Transition‐metal‐based oxyhydroxides are efficient catalysts in biomass electrooxidation towards fossil‐fuel‐free production of valuable chemicals. However, identification of active sites remains elusive. Herein, using cobalt oxyhydroxide (CoOOH) as the archetype and the electrocatalyzed glucose oxidation reaction (GOR) as the model reaction, we track dynamic transformation of the electronic and atomic structure of the catalyst using a suite of operando and ex situ techniques. We reveal that two types of reducible Co3+‐oxo species are afforded for the GOR, including adsorbed hydroxyl on Co3+ ion (μ1‐OH−Co3+) and di‐Co3+‐bridged lattice oxygen (μ2‐O−Co3+). Moreover, theoretical calculations unveil that μ1‐OH−Co3+ is responsible for oxygenation, while μ2‐O−Co3+ mainly contributes to dehydrogenation, both as key oxidative steps in glucose‐to‐formate transformation. This work provides a framework for mechanistic understanding of the complex near‐surface chemistry of metal oxyhydroxides in biomass electrorefining. [ABSTRACT FROM AUTHOR]