物理化学学报2022，Vol.38Issue(7)：7-15,9.DOI:10.3866/PKU.WHXB202108028
一维/二维W18O49/多孔g-C3N4梯形异质结构建及其光催化析氢性能研究
Construction of 1D/2D W18O49/Porous g-C3N4 S-Scheme Heterojunction with Enhanced Photocatalytic H2 Evolution
摘要
Abstract
Photocatalytic hydrogen production is an effective strategy for addressing energy shortage and converting solar energy into chemical energy.Exploring effective strategies to improve photocatalytic H2 production is a key challenge in the field of energy conversion.There are numerous oxygen vacancies on the surface of non-stoichiometric W18O49(WO),which result in suitable light absorption performance,but the hydrogen evolution effect is not ideal because the band potential does not reach the hydrogen evolution potential.A suitable heterojunction is constructed to optimize defects such as high carrier recombination rate and low photocatalytic performance in a semiconductor.Herein,2D porous carbon nitride(PCN)is synthesized,followed by the in situ growth of 1D WO on the PCN to realize a step-scheme(S-scheme)heterojunction.When WO and PCN are composited,the difference between the Fermi levels of WO and PCN leads to electron migration,which balances the Fermi levels of WO and PCN.Electron transfer leads to the formation of an interfacial electric field and bends the energy bands of WO and PCN,thereby resulting in the recombination of unused electrons and holes while leaving used electrons and holes,which can accelerate the separation and charge transfer at the interface and endow the WO/PCN system with better redox capabilities.In addition,PCN with a porous structure provides more catalytic active sites.The photocatalytic performance of the sample can be investigated using the amount of hydrogen released.Compared to WO and PCN,20％WO/PCN composite has a higher H2 production rate(1700μmol·g-1·h-1),which is 56 times greater than that of PCN(30 μmol·g-1·h-1).This study shows the possibility of the application of S-scheme heterojunction in the field of photocatalytic H2 production.关键词
S型/光催化制氢/W18O49/多孔氮化碳/异质结Key words
S-scheme/Photocatalytic H2 production/W18O49/Porous carbon nitride/Heterojunction分类
化学化工引用本文复制引用
黄悦,梅飞飞,张金锋,代凯,Graham Dawson..一维/二维W18O49/多孔g-C3N4梯形异质结构建及其光催化析氢性能研究[J].物理化学学报,2022,38(7):7-15,9.基金项目
This work was supported by the National Natural Science Foundation of China(51572103 and 51973078),the Distinguished Young Scholar of Anhui Province,China(1808085J14)and the Major projects of Education Department of Anhui Province,China(KJ2020ZD005).国家自然科学基金(51572103,51973078),安徽省杰出青年基金(1808085J14)和安徽省教育厅重大项目(KJ2020ZD005) （51572103 and 51973078）
