Progresses and Prospects of Asymmetrically Coordinated Single Atom Catalysts for Lithium-Sulfur Batteries

Lithium-sulfur batteries(LSBs)are widely regarded as promising next-generation batteries due to their high theoretical specific capacity and low material cost.However,the practical applications of LSBs are limited by the shuttle effect of lithium polysulfides(LiPSs),electronic insulation of charge and discharge products,and slow LiPSs conversion reaction kinetics.Accordingly,the introduction of catalysts into LSBs is one of the effective strategy to solve the issues of the sluggished LiPS conversion.Because of their nearly 100%atom utilization and high electrocatalytic activity,single-atom catalysts(SACs)have been widely used as reaction mediators for LSBs’reactions.Excitingly,the SACs with asymmetric coordination structures have exhibited intriguing electronic structures and superior catalytic activities when compared to the traditional M-N_(4)active sites.In this review,we systematically describe the recent advancements in the installation of asymmetrically coordinated single-atom structure as reactions catalysts in LSBs,including asymmetrically nitrogen coordinated SACs,heteroatom coordinated SACs,support effective asymmetrically coordinated SACs,and bimetallic coordinated SACs.Particularly noteworthy is the discussion of the catalytic conversion mechanism of LiPSs spanning asymmetrically coordinated SACs.Finally,a perspective on the future developments of asymmetrically coordinated SACs in LSB applications is provided.

Review on multi-dimensional assembled S-scheme heterojunction photocatalysts

S-scheme heterostructure photocatalysts utilize the synergistic and superposition effects of materials,ef-fectively separating electrons and holes,maintaining strong redox capacity,and addressing issues en-countered by current photocatalytic reactions.This review explores the origins and unique benefits of S-scheme heterojunctions.Specifically,we summarized and discussed the effects of different dimensions of semiconductors constituting S-scheme heterojunctions and the similarities and differences in elec-tron transfer processes when constructing heterojunctions.Additionally,we analyzed several methods for proving the formation of S-scheme heterojunctions and the electron transfer process,both directly and indirectly.Finally,we review the applications of S-scheme heterojunctions in various fields of photo-catalysis,including photocatalytic water splitting,pollution degradation,CO_(2) reduction and other related photocatalytic applications.Our hope is that this review will provide an essential reference for the devel-opment and application of S-scheme heterojunction photocatalysis.

BiVO_(4),Bi_(2)WO_(6) and Bi_(2)MoO_(6) photocatalysis:A brief review

In recent years,photocatalytic technologies have been extensively studied and diffusely used in water splitting,decomposition of organic pollutants,reduction of carbon dioxide,etc.As a type of eye-catching semiconductors,BiVO_(4),Bi_(2)WO_(6),and Bi_(2)MoO_(6) (denoted as BiaAOb)have become a hotspot in photocatalytic researches due to their crystal structure stability,high light quantum and electronic transmission efficiency,and outstanding energy utilization capacity.However,pristine BiaAOb(A=V,W,and Mo)possesses several drawbacks,such as low separation efficiency of photo-excited electron-hole pairs,low specific surface area,as well as the poor quantum utilization,which restrict their photocatalytic performance.Considerable efforts,such as nanostructure modification,surface engineering,and heterojunction/homojunction fabrication,have been conducted to solve these problems.This integrated review aims to sum up recent advances in current studies on fabrication of high efficiency BiaAOb photocatalysts to accelerate the developments of BiaAOb-based materials in the photocatalysis(PC)field.The current challenges and prospects of BiaAOb are emphasized which stretches the existing fundamental theories of PC as well as provide a promising strategy to fabricate high efficiency BiaAOb catalysts to control environmental pollution and assist the sustainable development of energy.

Self-template formation of porous yolk-shell structure Mo-doped NiCo2O4 toward enhanced lithium storage performance as anode material

Hollow ternary metal oxides have shown enormous potential in lithium-ion batteries(LIBs),which is ascribed to their complex chemical composition,abundant active defect sites,and the synergy effect be-tween metals.In this work,we synthesized Mo-doped NiCo_(2)O_(4) porous spheres with yolk-shell structure by using a simple self-templating method.Surprisingly,other than the yolk-shell structure we had ob-tained,the inner core of the yolk-shell was also porous,which could fully enhance the electrolyte infil-tration and promote the transmission of lithium ions(Li+)and electrons(e−).The diameter of the porous core in the yolk-shell sphere was about 530 nm,and the outer shell’s thickness was up to 110 nm.In addition,the unique pores in the core appeared in the diameter of about 85 nm.With this structure,the volume expansion of the anode could be well inhibited during charge/discharge.It exhibited prominent electrochemical performance with high reversible capacity(1338 mA h g^(−1) at 100 mA g^(−1)),satisfactory cycle life(1360 mA h g^(−1) after 200 cycles at 100 mA g^(−1)),and exceptional rate capability(820 mA h g^(−1) at 2000 mA g^(−1))as anode material in LIBs.