Construction of AgI/Bi2MoO6/AgBi(MoO4)2 multi-heterostructure composite nanosheets for visible-light photocatalysis

Abstract

The AgI/Bi2MoO6/AgBi(MoO4)2 (ABM) multi-heterostructure nanosheet composite system for visible-light photocatalysis have been successfully constructed by a simple one-step calcination method. The ABM multi-heterostructure composite photocatalysts exhibited the obviously improved photocatalytic performance than the pristine Bi2MoO6, AgBi(MoO4)2, and AgI for the degradation of both Tetracycline hydrochloride (TC) and Rhodamine B (RhB). The apparent degradation rate for the ABM sample with the highest photocatalytic activity is 5.4 (TC) and 23.4 times (RhB) that of Bi2MoO6, 4.0 (TC) and 4.9 times (RhB) that of AgBi(MoO4)2, and 1.9 (TC) and 2.4 times (RhB) that of AgI, respectively. This ABM sample with the highest activity showed a Bi2MoO6/AgBi(MoO4)2 composite nanosheet morphology (lateral size: 1–5 u m, thickness: 90−130 nm) with a large amounts of small AgI nanocrystals (diameter: 2−25 nm) uniformly distributed on the surface of composite sheet. The outstanding performance of the ABM composite photocatalysts should be ascribed to the effective separation of photoinduced electron-hole pairs via the multi-heterostructure in ABM, the enhanced visible-light absorption, as well as the two-dimensional (2D) morphology benefitting to the exposure of plenty of surface reactive sites and significant reduction of migration distances of photogenerated carriers. It is hoped that this facile method for the fabrication of multi-heterostructure in our work could promote and inspire the other multicomponent functional nanomaterials used in the fields of not only photocatalysis, but also solar cells, sensors, catalysis, and so on, in the future.