Enhanced photocatalytic activity of BiOI under visible light irradiation by the modification of MoS2

Abstract

3D hierarchical BiOI nanostructures modified with MoS₂ were successfully fabricated through a simple solvent thermal process. The prepared heterostructured BiOI–MoS₂ nanocomposite exhibited excellent photocatalytic performance in the degradation of methyl orange under visible light irradiation. The photocatalytic activity of BiOI–MoS₂ increases with the increase of MoS₂ content first, then it decreases when MoS₂ content is over 0.5 wt%. The degradation efficiency of methyl orange could achieve 95% within 90 min in the presence of BiOI–0.5 wt% MoS₂, which is about two times higher than that of pristine BiOI nanostructures. The obviously improved photocatalytic performance of BiOI–MoS₂ could be mainly attributed to the significantly enhanced separation efficiency of photogenerated charge carriers. However, too much MoS₂ loading on the surface of BiOI will prevent light from reaching surface of BiOI and limit the efficiency of charge separation. Based on active species trapping experiments, holes (h⁺) were proved to be the main reactive species in the prepared BiOI–MoS₂ system.