A novel bicomponent Co3S4/Co@C cocatalyst on CdS accelerating charge separation for highly efficient photocatalytic hydrogen evolution

In order to realize the dream of practical application of hydrogen energy from solar energy and water, it is necessary to use efficient and earth-abundant cocatalysts for photocatalytic H2 evolution. Compared with one-component cocatalyst, the multicomponent cocatalysts with synergistic effect can effectively accelerate the separation of photogenerated electron-hole pairs in photocatalysis. Hence, a novel bicomponent Co3S4/Co@C cocatalyst on CdS semiconductor photocatalyst is successfully synthesized by a one-step hydrothermal method. The designed Co3S4/Co-CdS photocatalyst exhibits high-efficiency photocatalytic H2 evolution rate of 15.17 mmol h-1 g-1, which is 2.8 times higher than that of Pt-CdS. Furthermore, the quantum efficiency of Co3S4/Co-CdS reaches a maximum value of 16.80% at 475 nm. The significant improvement in the performance is owing to the unique energy level structure of Co3S4/Co-CdS photocatalyst, which has the maximum efficiency of charge separation and migration. This work not only presents a new protocol for constructing bicomponent cocatalysts on semiconductor structure, but also proves the bicomponent Co3S4/Co@C to be a promising and low-cost cocatalyst.