Interfacial properties of g-C_(3)N_(4)/TiO_(2) heterostructures studied by DFT calculations

Constructing the hetrostructure is a feasible strategy to enhance the performances of photocatalysts. However, there are still some fundamental details and mechanisms for the specific design of photocatalysts with heterostructure,which need further confirming and explain.In this work,g-C_(3)N_(4)-based heterostructures are constructed with TiO_(2) in different ways,and their intrinsic factors to improve the photocatalytic activity are systematically studied by density functional theory(DFT).When g-C_(3)N_(4) combines horizontally with TiO_(2) to form a heterostructure,the interaction between them is dominated by van der Waals interaction.Although the recombination of photo-generated electron-hole pair cannot be inhibited significantly,this van der Waals interaction can regulate the electronic structures of the two components,which is conducive to the participation of photo-generated electrons and holes in the photocatalytic reaction.When the g-C_(3)N_(4) combines vertically with TiO_(2) to form a heterostructure,their interface states show obvious covalent features,which is very beneficial for the photo-generated electrons’ and holes’ transport along the opposite directions on both sides of the interface.Furthermore,the built-in electric field of g-C_(3)N_(4)/TiO_(2) heterostructure is directed from TiO_(2) layer to g-C_(3)N_(4) layer under equilibrium,so the photo-generated electron-hole pairs can be spatially separated from each other.These calculated results show that no matter how g-C_(3)N_(4) and TiO_(2) are combined together,the g-C_(3)N_(4)/TiO_(2) heterostructure can enhance the photocatalytic performance through corresponding ways.

High-entropy oxides as energy materials:from complexity to rational design

High-entropy oxides(HEOs),with their multi-principal-element compositional diversity,have emerged as promising candidates in the realm of energy materials.This review encapsulates the progress in harnessing HEOs for energy conversion and storage applications,encompassing solar cells,electrocatalysis,photocatalysis,lithium-ion batteries,and solid oxide fuel cells.The critical role of theoretical calculations and simulations is underscored,highlighting their contribution to elucidating material stability,deciphering structure-activity relationships,and enabling performance optimization.These computational tools have been instrumental in multi-scale modeling,high-throughput screening,and integrating artificial intelligence for material design.Despite their promise,challenges such as fabrication complexity,cost,and theoretical computational hurdles impede the broad application of HEOs.To address these,this review delineates future research perspectives.These include the innovation of cost-effective synthesis strategies,employment of in situ characterization for micro-chemical insights,exploration of unique physical phenomena to refine performance,and enhancement of computational models for precise structure-performance predictions.This review calls for interdisciplinary synergy,fostering a collaborative approach between materials science,chemistry,physics,and related disciplines.Collectively,these efforts are poised to propel HEOs towards commercial viability in the new energy technologies,heralding innovative solutions to pressing energy and environmental challenges.