The construction of S-scheme heterojunctions can facilitate the transfer and separation of photogenerated carriers while preserving their strong redox capabilities. Loading single atoms onto the surface of photocatalysts can promote the adsorption and conversion of reactant molecules. Combining these two strategies to construct single-atom-modified S-scheme heterojunctions can simultaneously improve carrier separation and surface reaction kinetics, thereby achieving a significant enhancement in photocatalytic performance.
Herein, SnS₂/CdS S-scheme heterojunctions loaded with transition metal (TM = Pt, Pd, Au) single atoms were constructed. Through density functional theory (DFT) calculations, their geometric structure, electronic properties, surface hydrogen adsorption, and the mechanism of lactic acid (LA) oxidation reaction were investigated. The results indicate that the introduction of TM atoms enhances interfacial electron transfer. Notably, TM atoms anchored on the CdS surface can effectively modulate the p-band center of adjacent S atoms, thereby weakening the S–H bond and optimizing the hydrogen adsorption–desorption equilibrium. Meanwhile, TM atoms on the SnS₂ surface can enhance the adsorption energy of LA and lower the energy barrier of the rate-determining step in the dehydrogenation oxidation process. These findings demonstrate that strategically arranging metal single atoms on different components of an S-scheme heterojunction can synergistically enhance both the reduction and oxidation half-reactions.
The work titled “A dual-functional single-atom modified SnS₂/CdS S-scheme photocatalyst for synergistic hydrogen production and lactic acid oxidation: A DFT study” was published on Acta Physico-Chimica Sinica (published on January 15, 2026).
DOI：10.1016/j.actphy.2026.100244