双内建电场驱动的D-A COFs/ZnIn2S4 S型异质结加速电荷分离实现纯水中高效光合成H2O2OA

The construction of dual built-in electric field(IEF)-driven S-scheme heterojunctions presents a promising strategy to accelerate efficient charge separation and improve charge utilization in photocatalytic H2O2 production.Herein,we report,the construction of a heterojunction based on donor-acceptor covalent organic frameworks(D-A COFs)TpAQ(synthesized from two monomers:1,3,5-triformylphloroglucinol(Tp)and 2,6-diaminoanthraquinone(AQ))and ZnIn2S4(ZIS),realizing a dual IEF-driven S-scheme heterojunction—one from the heterojunction interface and another from D-A interface within D-A COFs.In particular,the optimized TpAQ/ZIS-10 exhibits a significantly higher visible-light driven photocatalytic H2O2 production rate of 2362 μmol g-1 h-1 in pure water than TpAQ and ZIS by utilizing both the oxygen reduction reaction and water oxidation reaction pathways.Furthermore,the experimental results and theoretical calculations revealed that the synergistic effect of dual IEF in TpAQ/ZIS heterojunction significantly facilitates efficient charge carrier transfer and separation.This work provides valuable insight for constructing highly efficient S-scheme heterojunctions with dual IEF.