Cooperation of congenital and acquisitus sulfur vacancy for excellent photocatalytic hydrogen peroxide evolution of CdS nanorods from air

Congenital sulfur vacancies (Sv) and acquisitus Sv in-situ created in the reaction process co-contribute to the remarkably increased carrier separation efficiency and O 2 adsorption ability of CdS nanorods-24h (CdS NRs), thus rendering a superior photocatalytic H 2 O 2 production rate of 2974.7 umol/g/h under visible light. • Cooperation of congenital and acquisitus Sv in CdS nanorods for excellent photocatalytic H 2 O 2 evolution from air. • Acquisitus Sv concentration in CdS samples inversely correlates with congenital Sv concentration. • CdS nanorods with abundant congenital Sv exhibit higher carrier separation efficiency and stronger O 2 adsorption ability. • The O 2 adsorption energy on the surface of CdS nanorods with Sv is much lower than that of defect-free CdS. • CdS nanorods-24h delivers a superior photocatalytic H 2 O 2 yield rate (2974.7 umol/g/h) under visible light. Photocatalysis over semiconductors for producing hydrogen peroxide (H 2 O 2 ) due to its renewable and sufficient sunlight as driving force has attracted more attention. However, the H 2 O 2 evolution performance that is severely dependent on surface structure of photocatalysts is still inferior. Here we design sulfur vacancies (Sv)-rich CdS nanorods (CdS NRs), and disclose that the congenital Sv and acquisitus Sv in-situ created in the reaction process co-contribute to the efficient photocatalytic H 2 O 2 production. The CdS NRs with abundant congenital Sv exhibit higher carrier separation efficiency and remarkably stronger O 2 adsorption ability. Importantly, we discover that the Sv concentration in all the CdS serial samples increases after the H 2 O 2 evolution reaction compared with that before photocatalytic reaction, and the increase level of acquisitus Sv concentration inversely correlates with congenital Sv concentration. Theoretical calculations confirm that the O 2 adsorption energy on the surface of CdS NRs with Sv (-0.723 eV) is much lower than that of defect-free CdS (1.293 eV). Optimized by the two types of Sv, CdS NRs-24h delivers a superior photocatalytic H 2 O 2 production rate of 2974.7 μmol g -1 h -1 under visible light, far exceeding the previously reported sulfide photocatalysts. This work is anticipated to offer new perspectives into designing and understanding of sulfides for photocatalytic H 2 O 2 evolution.