Multisite Cocatalysis: Single atomic Pt2+/Pt0 active sites synergistically improve the simulated sunlight driven H2O-to-H2 conversion performance of Sb2S3 nanorods.

Anchoring of single-atom Pt2+ and Pt0 on the surface of Sb 2 S 3 NRs highly benefits to the formation of metal (Pt)-semiconductor (Sb 2 S 3) electric interaction, which synergistically improves the broadband light harvesting and promotes the Sb 2 S 3 -to-Pt electron transfer following inhibited photoexciton recombination kinetics and enhanced H proton adsorption capacity, resulting higher and more durable photoactivity for H 2 O-to-H 2 conversion. [Display omitted] • Single atomic Pt2+/Pt0 active sites were successfully anchored on the Sb 2 S 3 nanorods. • The metal (Pt)-semiconductor (Sb 2 S 3) electric interaction was formed. • The optimal composite catalyst possesses enhanced H proton adsorption capacity. • Higher and more durable photoactivity for H 2 O-to-H 2 conversion were achieved. • The mechanism of multisite cocatalysis for photoactivity improvement was elucidated. Single atomic metal (SAM) cocatalysis is a potential strategy to improve the performance of photocatalytic materials. However, the cocatalytic mechanism of SAM sites in different valence states is rarely reported. Herein, single atomic Pt2+/Pt0 active sites were anchored on Sb 2 S 3 nanorods to synergistically improve the photoactivity for hydrogen production under simulated sunlight. Experimental results and density functional theory calculations indicated that the coexistence of single atomic Pt2+/Pt0 sites synergistically improves the broadband light harvesting and promotes the Sb 2 S 3 -to-Pt electron transfer following inhibited photoexciton recombination kinetics and enhanced H proton adsorption capacity, resulting higher and more durable photoactivity for hydrogen production. Therefore, the optimal Sb 2 S 3 -Pt 0.9‰ composite catalyst achieved remarkably enhanced hydrogen evolution rate of 1.37 mmol∙g−1∙h−1 (about 105-fold greater of that of Sb 2 S 3 NRs) under faintly alkaline condition, and about 5.41 % of apparent quantum yield (AQY 700 nm) was achieved, which shows obvious superiority in hydrogen production by contrasting with the reported Sb 2 S 3 -based photocatalysts and conventional semiconductor photocatalytic materials modified with noble metals. This study elucidate a well-defined mechanism of multisite cocatalysis for photoactivity improvement. [ABSTRACT FROM AUTHOR]