MoB/Mn0.43Cd0.57S Schottky heterojunction composites: A novel and noble-metal-free photocatalyst for high-efficiency photocatalytic H2 production

The development of efficient and low-cost photocatalysts has always been sought in H 2 production from water cracking. Herein, a series of MoB/Mn 0.43 Cd 0.57 S composites were developed for high-performance photocatalytic H 2 production. Mn 0.43 Cd 0.57 S nanoparticles were deposited on bulk metalloid MoB via a hydrothermal method (as confirmed by morphology tests) to construct a Schottky heterojunction. In the composites, the Fermi levels of Mn 0.43 Cd 0.57 S and MoB were rearranged (as confirmed by ultraviolet photoelectron spectroscopy) and the electrons of Mn 0.43 Cd 0.57 S rapidly migrated to MoB (as confirmed by X-ray photoelectron spectroscopy). Ultimately, the formation of the Schottky heterojunction significantly improved interfacial carrier separation, leading to efficient H 2 production. MoB, which exhibits a Pt-like electronic structure, provided active sites for H 2 evolution in the heterojunction composites. Furthermore, compared with those of Mn 0.43 Cd 0.57 S, the visible-light absorption capacity and H 2 evolution kinetics of the heterojunction composites were also vastly improved. After photocatalytic H 2 production, the performance of all heterojunction composites markedly increased. The performance of the composite with 20 % MoB/Mn 0.43 Cd 0.57 S) was the highest (4146.92 μmol·g −1 ·h −1 ), which was 11.3 times that of Mn 0.43 Cd 0.57 S (367.56 μmol·g −1 ·h −1 ). The stability of the composites was further evaluated, and the 20MoB/Mn 0.43 Cd 0.57 S composite lost only 12.8 % of its activity, indicating its excellent photostability. The underlying mechanism of H 2 production over the heterojunction composites was also investigated. This work provides an innovative approach for achieving high-efficiency H 2 production in a sulfide solid solution modified by a metalloid MoB cocatalyst.