Ni0.7Co0.3P nanoparticle-loaded MnCo2S4 yolk–shell nanoflowers with a Z-scheme heterojunction for efficient photocatalytic hydrogen evolution

Abstract

Hydrogen, a source of clean energy, has great potential for applications in the field of renewable energy. Developing low-cost, high-efficiency composite photocatalysts with high performance and good stability characteristics has broad application prospects. In this study, the Ni_0.7Co_0.3P/MnCo₂S₄ composite photocatalysts were prepared by the in situ deposition of Ni_0.7Co_0.3P nanoparticles on the surface of the MnCo₂S₄ yolk–shell nanoflowers derived from MnCo-layered double hydroxide. The hydrogen production performance of the photocatalysts was modified by regulating the Co-dopant amount in Ni_1−xCo_xP and the loading amount of Ni_0.7Co_0.3P. The measurements illustrated that the hydrogen generation rate of Ni_0.7Co_0.3P/MnCo₂S₄ under visible light irradiation was markedly increased and the composite photocatalyst maintained good stability. The modification of Ni_0.7Co_0.3P helped to enhance its light absorption capacity, thus providing more active sites. Meanwhile, the Z-scheme heterojunction formed between MnCo₂S₄ and Ni_0.7Co_0.3P could expedite the shift of photogenerated carriers, limit the recombination of photogenerated electrons and holes and contribute to H₂ production. This work affords a novel approach for the development of high-performance composite photocatalysts.