Giant enhancement of photocatalytic H2 production over KNbO3 photocatalyst obtained via carbon doping and MoS2 decoration

This paper was designed for the first time to improve the photocatalytic activity of KNbO3 via carbon doping and MoS2 decoration simultaneously. The efficient photocatalytic hydrogen production was realized on the MoS2/C-KNbO3 composite under simulated sunlight irradiation in the present of methanol and chloroplatinic acid. The optimal composite presents a H2 production rate of 1300  μmol·g−1·h−1, which reaches 260 times that of pure KNbO3. Characterization results of the synthesized composite indicates that the introduction of a small amount of carbon into the KNbO3 lattice greatly hinders the recombination of electron-hole pairs. The decoration of MoS2 further induces the separation of charge carriers via trapping the electron in the conduction band of C-KNbO3, which is proven by the EIS and transient photocurrent response analyses. The remarkably enhanced separation efficiency of electron-hole pairs is believed to be the origin of the excellent photocatalytic performance, though other changes in surface area and optical property may also contribute the photocatalytic process. This study provides a feasible way for the design and preparation of novel photocatalysts with high efficiency.