Two-dimensional nickel nanosheets coupled with Zn0.5Cd0.5S nanocrystals for highly improved visible-light photocatalytic H2 production

Abstract

Ni-based precious-metal-free cocatalysts have attracted copious attention due to their nature-friendly and cost-effectiveness compared with platinum (Pt) during photocatalytic H2 evolution. However, the typical morphologies and structures of Ni-based cocatalysts (e.g., Ni) focus on the zero-dimensional (0D) nanoparticles. Herein, we demonstrate a two-dimensional (2D) nickel nanosheets cocatalyst decorated Zn0.5Cd0.5S nanocrystals that pays attention to visible-light-motivated photocatalytic H2 generation. By rationally introducing Ni nanosheets to modify Zn0.5Cd0.5S nanoparticles, a series of unique 2D/0D Ni/Zn0.5Cd0.5S nanohybrids with different Ni contents were synthesized. The optimized Ni-5%/Zn0.5Cd0.5S composite possesses a high H2 production rate of 5930μmolh−1g−1 upon visible-light (λ > 420 nm) illumination, which was about 33.7 and 15.4-fold more elevated than those of Zn0.5Cd0.5S nanocrystals, and Pt/Zn0.5Cd0.5S, respectively. Combining photoelectrochemical (PEC) and photoluminescence (PL) studies, the conspicuous enhancement in photocatalytic H2 generation was stemmed from the Ni nanosheets cocatalyst act as an electron-transfer layer to extract photoexcited electrons from Zn0.5Cd0.5S and offer enormous reaction sites for H2 production. This work verifies Ni nanosheets' capability for photocatalytic water splitting. The Ni/Zn0.5Cd0.5S composed of magnetic metal and ternary metal sulfide can be extended to other photocatalytic applications, such as dyes degradation and CO2 reduction.