BiOI/BiVO₄ Two-Dimensional Heteronanostructures for Visible-Light Photocatalytic Degradation of Rhodamine B

By virtue of the facile anion-exchange technique, smart BiOI/BiVO4 two-dimensional (2D) heteronanostructure (HNS) photocatalysts targeted for the degradation of organic pollutants have been developed by the in situ growth of BiVO4 on the scaffolds of BiOI nanoplates. The as-obtained BiOI/BiVO4 HNSs exhibited excellent 2D structure as templates of BiOI nanoplates and well structure stability due to the in situ growth pattern of BiVO4 on BiOI. The 2D HNSs exhibited superior photocatalytic activities, especially the V/I8 2D HNSs (V:I = 80%), exhibited the highest Rhodamine B (RhB) and salicylic acid (SA) degradation rates, which are 29.8 times (RhB) and 15.7 times (SA) those of the individual BiVO4 and 6.4 times (RhB) and 10 times (SA) those of BiOI, respectively. Such excellent photocatalytic activities should be attributed to the organic combination of the 2D structure and heterojunction, as verified by the detailed morphology and composition characterizations. The well-known unique advantages of 2D nanostructures such as efficient light harvesting, quick reactant transport, exposure of plenty of surface reactive sites, and significantly reduced perpendicular migration distances of photogenerated carriers from the interior to the surface of materials, coupled with enhanced carrier separation behavior due to the built-in field at the heterointerface endow the 2D HNSs with ultrastrong photocatalytic abilities. It is hoped that our work could offer a paradigm for the development of smart 2D HNS optoelectronic functional materials used in photosynthesis, solar cells, sensors, catalysis, and so on, in the future.