Systematic investigation on the rational design and optimization of bi-based metal oxide semiconductors in photocatalytic applications.

Abstract

To address the global energy shortage and mitigate greenhouse gas emissions on a massive scale, it is critical to explore novel and efficient photocatalysts for the utilization of renewable resources. Bi-based metal oxide (BixMOy) semiconductors composed of bismuth, transition metal, and oxygen atoms have demonstrated improved photocatalytic activity and product selectivity. The vast number of element combinations available for BixMOy materials provides a huge compositional space for the rational design and isolation of promising photocatalysts for specific applications. In this study, we have systematically investigated the electronic and optical properties over Bi2O3 and a series of selected BixMOy group materials (BiVO4, BiFeO3, BiCoO3, and BiCrO3) by calculating band structure, basic optical property features, mobility and separation of charge carriers. It is clearly noted that band gap and band edge position of the BixMOy group materials can be tuned in a wide range in comparison to Bi2O3. Similarly, the light response of BixMOy also can be broadened from the ultraviolet to the visible light region by adjusting selection of transition metals. Additionally, the analysis of effective mass of charge carriers of these materials further confirms their possibility in photocatalytic reaction applications because of appropriate separation efficiency and mobility of carriers.