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

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.