Tailoring AgI nanoparticles for the assembly of AgI/BiOI hierarchical hybrids with size-dependent photocatalytic activities

A facile ion exchange route between BiOI hierarchical microspheres and AgNO3 solution is explored to synthesize AgI/BiOI hierarchical hybrids that consist of AgI nanoparticles (NPs) uniformly anchored on the surface of BiOI nanosheets. With the addition of poly(vinylpyrrolidone) (PVP) surfactant molecules, the size of the AgI NPs can be tailored in the range of 55-16 nm. Evaluated by the photodecomposition of 2,4-dichlorophenol (2,4-DCP) solution under visible light irradiation, the AgI NPs/BiOI hybrids displayed highly efficient photocatalytic activities. What is more, as the size of the AgI NPs decreases, the AgI/BiOI hybrids exhibit enhanced photocatalytic performance, which is believed to be related to the larger number of surface active sites and faster spatial charge transfer.