Surface Atomic Configurations of MnO₂ Regulating the Immobilization of Sulfides in Lithium Sulfur Battery

High-performance energy storage systems have generated considerable interest in recent years. Metal-oxide-based lithium sulfur batteries (LSBs) have been widely studied for its enhanced performance caused by the suppression of dissolution and the shuttle effect. However, three interactions, between sulfides and metal oxides, are difficult to distinguish, including sulfur–metal, sulfur–oxide, and lithium–oxide, which impeded researchers to understand the mechanism and the further design of cathodes. Herein, by performing density function theory calculations, we systematically studied the influence of O content on different MnO2 surfaces about the adsorption of sulfides. Through analyzing the relationship of O content and binding energy, charge transfer, orbital hybridization, as well as the catalytic effect, we found that with the increase of O content the Coulomb interaction between sulfides and metal oxides is dominated by O atoms, and the hybridization is not heavily influenced by the O content since the hybridization of S–O is the strongest for sulfides on all selected surfaces. The O content also regulates the catalytic effect, and with the increase of O content, the conversion energies of sulfides are reduced, which could accelerate the charge/discharge processes. These findings could help us to understand the mechanism of metal oxide behaviors in LSBs and will be beneficial for the design and controllable fabrication of cathodes of LSBs

Additional file 1 of Utilizing serum metabolomics for assessing postoperative efficacy and monitoring recurrence in gastric cancer patients

Supplementary Material 1: 194 metabolites identified in positive ion mod

Modulation of Local Charge Distribution Stabilized the Anionic Redox Process in Mn-Based P2-Type Layered Oxides

An anionic redox reaction is an extraordinary method for obtaining high-energy-density cathode materials for sodium-ion batteries (SIBs). The commonly used inactive-element-doped strategies can effectively trigger the O redox activity in several layered cathode materials. However, the anionic redox reaction process is usually accompanied by unfavorable structural changes, large voltage hysteresis, and irreversible O2 loss, which hinders its practical application to a large extent. In the present work, we take the doping of Li elements into Mn-based oxide as an example and reveal the local charge trap around the Li dopant will severely impede O charge transfer upon cycling. To overcome this obstacle, additional Zn2+ codoping is introduced into the system. Theoretical and experimental studies show that Zn2+ doping can effectively release the charge around Li+ and homogeneously distribute it on Mn and O atoms, thus reducing the overoxidation of O and improving the stability of the structure. Furthermore, this change in the microstructure makes the phase transition more reversible. This study aimed to provide a theoretical framework for further improve the electrochemical performance of similar anionic redox systems and provide insights into the activation mechanism of the anionic redox reaction

Amorphous CeO₂–Cu Heterostructure Enhances CO₂ Electroreduction to Multicarbon Alcohols

Electrochemical conversion of carbon dioxide (CO2) gas to value-added chemicals such as multicarbon (C2+) alcohols is a promising and attractive decarbonization strategy. However, there are tremendous challenges in tuning the intrinsic activity and selectivity of the catalysts to produce C2+ alcohols. In this work, we prepared a CeO2–Cu composite catalyst via a combination of metallurgy and dealloying method. The interfacial sites of amorphous CeO2–Cu heterostructure improve the adsorption of key reaction intermediates *CO and promote the C–C coupling. Significantly, they also stabilize *CH2CHO at the bifurcation step, steering the reaction pathway toward the formation of C2+ alcohols over ethylene. The CeO2–Cu catalyst achieves a remarkable faradaic efficiency of 32.9% ± 2.6% for C2+ alcohols at −0.6 V vs RHE. This work demonstrates an effective strategy of improving the intrinsic activity and selectivity of the Cu-based catalysts for the generation of C2+ alcohols

Support Amorphization Engineering Regulates Single-Atom Ru as an Electron Pump for Nitrogen Photofixation

Single-atom photocatalysts exhibit great potential for converting solar energy into value-added chemicals or fuels, but the insufficient efficiency of charge transfer from light-absorbed units to single-atom catalytic sites limits the overall photocatalytic performance. Herein, we developed an amorphization strategy of ferric oxide support to accelerate the enrichment of photogenerated electrons to single-atom Ru for enhanced nitrogen photofixation. The ammonia yield rate of Ru single atoms distributed on amorphous ferric oxide nanosheets (Ru1/2DAF) in pure water reached 213 μmol·gcat.–1·h–1, even four times higher than that of the crystalline counterpart. Mechanistic studies indicated that the amorphous structure could efficiently modulate the electronic density of states to reduce the electron-transfer energy barrier and guide electrons from amorphous support to Ru 4d orbitals via d­(Ru)–d­(Fe) coupling. This work provides fresh insights on the design of single-atom photocatalysts and emphasizes the importance of the charge transfer behavior in tuning the catalytic activity

Monitoring Electron Flow in Nickel Single-Atom Catalysts during Nitrogen Photofixation

An efficient catalytic system for nitrogen (N2) photofixation generally consists of light-harvesting units, active sites, and an electron-transfer bridge. In order to track photogenerated electron flow between different functional units, it is highly desired to develop in situ characterization techniques with element-specific capability, surface sensitivity, and detection of unoccupied states. In this work, we developed in situ synchrotron radiation soft X-ray absorption spectroscopy (in situ sXAS) to probe the variation of electronic structure for a reaction system during N2 photoreduction. Nickel single-atom and ceria nanoparticle comodified reduced graphene oxide (CeO2/Ni-G) was designed as a model catalyst. In situ sXAS directly reveals the dynamic interfacial charge transfer of photogenerated electrons under illumination and the consequent charge accumulation at the catalytic active sites for N2 activation. This work provides a powerful tool to monitor the electronic structure evolution of active sites under reaction conditions for photocatalysis and beyond

Source Data

These data are the source data of "Selective and energy-efficient electrosynthesis of ethylene from CO2 by tuningthe valence of Cu catalysts through aryl diazonium functionalization" manuscript in Nature Energy.</p