Anisotropic heteronanocrystals of Cu2O-2D MoS2 for efficient visible light driven photocatalysis

Abstract

Solar energy driven production of chemicals by photocatalysis holds great potential for solving the energy and environmental issues that are now being faced. However, the practical application of photocatalysis is limited because of low light absorbing efficiency, fast charge recombination rate, and low durability of photocatalysts. Herein we developed efficient solar energy-harvesting anisotropic binary heteronanocrystals (HNCs) composed of chemically exfoliated MoS2 (ce-MoS2) sheets and shape-controlled Cu2O NCs including cubic Cu2O (Cu2Ocube) and octahedral Cu2O NCs (Cu2Oocta). Because Cu2Ocube and Cu2Oocta are enclosed by the {100} and {111} facets, respectively, binary Cu2Ocube-MoS2 and Cu2Oocta-MoS2 HNCs can be considered as effective platforms for investigating the effects of surface structure and anisotropic morphology on photocatalytic reactions. The photocatalytic performance of Cu2O-MoS2 HNCs highly depended on both the surface facets of Cu2O NCs and the manner of Cu2O NCs and ce-MoS2 sheets coupling. The prepared anisotropic binary Cu2Ocube-MoS2 HNCs showed 2.5 times enhanced photocatalytic activity during hydrogen (H-2) production compared with Cu2Oocta-MoS2 HNCs. In addition, the degradation of theophylline under visible light irradiation was 2 times faster with Cu2Ocube-MoS2 HNCs than with Cu2Oocta-MoS2 HNCs because of synergistic structural and compositional benefits.