双功能单原子修饰SnS2/CdS S型光催化剂用于协同产氢与乳酸氧化的DFT研究OA

Designing efficient S-scheme photocatalysts for simultaneous H2 evolution and organic oxidation is highly desirable for sustainable energy conversion.Herein,a novel SnS2/CdS S-scheme heterojunction loaded with transition metal single atoms(TM=Pt,Pd,Au)was constructed.Systematic density functional theory(DFT)calculations are performed to investigate the geometric structure,electronic properties,and the mechanisms of surface H adsorption and lactic acid(LA)oxidation reactions.The results reveal that in the heterojunction,electrons transfer from CdS to SnS2 through interfacial Cd-S bonds,forming a stable composite structure,while the TM single atoms are stabilized by forming TM-S bonds with surface S atoms.The incorporation of TM atoms enhances the interfacial electron transfer.Notably,the TM atoms anchored on the CdS surface effectively modulate the p-band center of neighboring S atoms,thereby weakening the S-H bond and optimizing the H adsorption-desorption equilibrium.Concurrently,those on the SnS2 surface enhance the adsorption energy of LA and reduce the energy barrier of the rate-determining step in the dehydrogenation oxidation process.This work demonstrates that the strategic placement of single atoms on different components of an S-scheme heterojunction can synergistically enhance both the reduction and oxidation half-reactions,offering profound insights for the rational design of high-performance single-atom-loaded S-scheme photocatalytic systems for cooperative H2 production and value-added chemical synthesis.