Oxygen-contained amorphous MoSx cocatalyst by one-step photodeposition to enhance H-adsorption affinity for efficient photocatalytic H2 generation

Traditional bulk MoS2 as an effective H2-evolution cocatalyst is mainly subjected to the weak hydrogen-adsorption ability of high-porpotion saturated S, resulting in a slow interfacial H2-evolution reaction. In this paper, an efficient strategy for enhancing hydrogen adsorption of saturated S by manipulating electron density through O atoms is proposed to boost photocatalytic performance of CdS. Simultaneously, amorphization of MoS2 can further increase the unsaturated active S sites. Herein, oxygen-contained amorphous MoSx (a-MoOSx) nanoparticles (10–30 nm) were tightly loaded on the CdS surface through a mild photoinduced deposition method by using (NH4)2[MoO(S4)2] solution as the precursor at room temperature. The photocatalytic H2-evolution result showed that the a-MoOSx/CdS performed the superior H2-production activity (382 µmol·h−1, apparent quantum efficiencies (AQE) = 11.83%) with a lot of visual H2 bubbles, which was 54.6, 2.5, and 5.1 times as high as that of CdS, MoSx/CdS, and annealed a-MoOSx/CdS, respectively. Characterizations and density functional theory (DFT) calculations revealed the mechanism of improved H2-evolution activity is that the O heteroatom in amorphous MoOSx can enhance the atomic H-adsorption ability by manipulating the electron density to form electron-deficient S(2−δ)− sites. This study provides a new idea to improve the efficiency and number of H2-evolution active sites for developing efficient cocatalysts in the field of photocatalytic hydrogen evolution.