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 H-2-evolution cocatalyst is mainly subjected to the weak hydrogen-adsorption ability of highporpotion saturated S, resulting in a slow interfacial H-2-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, oxygencontained 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(S-4)(2)] solution as the precursor at room temperature. The photocatalytic H-2-evolution result showed that the a-MoOSx/CdS performed the superior H-2-production activity (382 mu mol center dot h(-1), apparent quantum efficiencies (AQE) = 11.83%) with a lot of visual H-2 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 H-2-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-d)- sites. This study provides a new idea to improve the efficiency and number of H-2-evolution active sites for developing efficient cocatalysts in the field of photocatalytic hydrogen evolution.