Tailoring Morphologies, Photocatalytic Activity, and Energy Bands of Bi25FeO40 via Valence State Transformation of Doped V Ions

Photocatalysts with suitable nanostructures and excellent photocatalytic activity driven by solar light are in great demand for rapidly eliminating the organic pollutants from wastewater. In order to improve the photocatalytic activities, three main factors should be considered, including band gap, band structure, and morphologies. Most of the previous studies only focused on manipulating one factor, such as the band gap by element doping. However, studies on enhancing photocatalytic activities by designing the band structure and morphologies are challenging, due to the difficulity to control the three parameters at the same time. Here, the V-doped Bi25FeO40 (Bi25Fe1-xVxO40) was demonstrated as a great system to manipulate the photocatalytic activities by designing the band structure and morphologies. With the simple hydrothermal methods, Bi25Fe1-xVxO40 with different flower-like morphologies and band structures were prepared. Surprisingly, the blooming and withering processes of the artificial architectures could be precisely tuned through different V concentrations. The controllable microstructures possess the high visible light absorption and enhanced photocatalytic activity. These results offer a model to reveal how the doping element can synchronously manipulate the particle morphology, band gap, and band structures, which is a key step to design new photocatalytic materials.