Grinding-assisted heterogeneous nucleation of BiOAc on MoS2 nanoflowers to heterojunction with good visible-light photocatalytic performance

Abstract

Bismuth oxide subacetate (CH3COO(BiO); BiOAc) with a large band gap energy (Eg) was first applied as an ultraviolet-light-driven photocatalyst in our group. MoS2 nanoflowers have been used to improve the visible-light photocatalytic activity of bismuth-based semiconductors with wide Eg because of their good visible-light response. Herein, the grinding-assisted solid-state reaction method was used to prepare a MoS2/BiOAc composite to improve the visible-light photoreactivity of BiOAc. As compared with commonly used wet chemical and hydrothermal routes, the grinding-assisted synthesis facilitated heterogeneous nucleation, which was beneficial to achieving close contact and subsequent charge transfer and separation at the interfaces, resulting in enhanced photocatalytic activity for malachite green, methylene blue, and antibiotic tetracycline degradation under visible-light irradiation. Notably, the dispersion in the mixing solution of ethanol and water (v/v=1) of MoS2 nanosheets induced self-assembly into flower-like nanostructures, thus enhancing the photocatalytic activity of MoS2/BiOAc. A possible mechanism for visible-light photocatalysis of MoS2/BiOAc was proposed.