Bismuth-based photocatalytic semiconductors: Introduction, challenges and possible approaches

Bismuth-based semiconductors are a unique and promising group of recently developed advanced photocatalytic materials. They have been widely applied in several areas including the generation of H2 by splitting water, decomposition of organic and inorganic pollutants in both wastewater and polluted air, and organic synthesis through harvesting the energy of light. The electronic structure of bismuth-based semiconductors confers them with a suitable band gap for visible-light response and a well-dispersed valence band composed of hybrid orbitals of Bi6s and O2p, making them a promising candidate when compared to other metal oxide semiconductors. In addition, they are simple to operate and prepare with controlled morphologies, making them attractive as potential photocatalysts. The purposes of this review are (1) summarization of advanced bismuth-based compounds that have been applied to date, (2) statement of challenges facing this material and possible approaches to overcome them, and (3) suggestions for future work.