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

Abstract

In order to realize the dream of the 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 a one-component cocatalyst, the multicomponent cocatalysts with a synergistic effect can effectively accelerate the separation of photogenerated electron–hole pairs in photocatalysis. Hence, a novel bicomponent Co₃S₄/Co@C cocatalyst on a CdS semiconductor photocatalyst is successfully synthesized by a one-step hydrothermal method. The Co₃S₄/Co-CdS photocatalyst obtained exhibits a highly efficient 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 because of the unique energy level structure of the 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 a semiconductor structure, but also proves that the bicomponent Co₃S₄/Co@C is a promising and low-cost cocatalyst.