物理化学学报2021，Vol.37Issue(6)：18-32,15.DOI:10.3866/PKU.WHXB202009030
g-C3N4表面改性及其光催化制H2与CO2还原研究进展
Recent Advances in Surface-Modified g-C3N4-Based Photocatalysts for H2 Production and CO2 Reduction
摘要
Abstract
Solar energy is the largest renewable energy source in the world and the primary energy source of wind energy,tidal energy,biomass energy,and fossil fuel.Photocatalysis technology is a sunlight-driven chemical reaction process on the surface of photocatalysts that can generate H2 from water,decompose organic contaminants,and reduce CO2 into organic fuels.As a metal-free polymeric material,graphite-like carbon nitride (g-C3N4) has attracted significant attention because of its special band structure,easy fabrication,and low costs.However,some bottlenecks still limit its photocatalytic performance.To date,numerous strategies have been employed to optimize the photoelectric properties of g-C3N4,such as element doping,functional group modification,and construction of heterojunctions.Remarkably,these modification strategies are strongly associated with the surface behavior of g-C3N4,which plays a key role in efficient photocatalytic performance.In this review,we endeavor to provide a comprehensive summary of g-C3N4-based photocatalysts prepared through typical surface modification strategies (surface functionalization and construction of heterojunctions) and elaborate their special light-excitation and response mechanism,photo-generated carrier transfer route,and surface catalytic reaction in detail under visible-light irradiation.Moreover,the potential applications of the surface-modified g-C3N4-based photocatalysts for photocatalytic H2 generation and reduction of CO2 into fuels are summarized.Finally,based on the current research,the key challenges that should be further studied and overcome are highlighted.The following are the objectives that future studies need to focus on:(1) Although considerable effort has been made to develop a surface modification strategy for g-C3N4,its photocatalytic efficiency is still too low to meet industrial application standards.The currently obtained solar-to-hydrogen (STH) conversion efficiency of g-C3N4 for H2 generation is approximately 2％,which is considerably lower than the commercial standards of 10％.Thus,the regulation of the surface/textural properties and electronic band structure of g-C3N4 should be further elucidated to improve its photocatalytic performance.(2) Significant challenges remain in the design and construction of g-C3N4-based S-scheme heterojunction photocatalysts by facile,low-cost,and reliable methods.To overcome the limitations of conventional heterojunctions thoroughly,a promising S-scheme heterojunction photocatalytic system was recently reported.The study further clarifies the charge transfer route and mechanism during the catalytic process.Thus,the rational design and synthesis of g-C3N4-based S-scheme heterojunctions will attract extensive scientific interest in the next few years in this field.(3) First-principle calculation is an effective strategy to study the optical,electrical,magnetic,and other physicochemical properties of surface strategy modified g-C3N4,providing important information to reveal the charge transfer path and intrinsic catalytic mechanism.As a result,density functional theory (DFT) computation will be paid increasing attention and widely applied in surface-modified g-C3N4-based photocatalysts.关键词
光催化/制氢/CO2还原/表面改性/异质结Key words
Photocatalysis/H2 generation/CO2 reduction/Surface modification/Heterojunction分类
化学化工引用本文复制引用
李云锋,张敏,周亮,杨思佳,武占省,马玉花..g-C3N4表面改性及其光催化制H2与CO2还原研究进展[J].物理化学学报,2021,37(6):18-32,15.基金项目
This work is supported by the National Natural Science Foundation of China (22008185,52063028),Scientific Research Program Funded by Shaanxi Provincial Education Department (19JK0376),Natural Science Basic Research Program of Shaanxi (2019JQ-841),and National Training Program of Innovation and Entrepreneurship for Undergraduates (S202010709004).国家自然科学基金(22008185,52063028),陕西省教育厅科研项目(19JK0376),陕西省自然科学基础研究项目(2019JQ-841),国家级大学生创新创业训练计划项目(S202010709004)资助 （22008185,52063028）
