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 BixMOymaterials 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 Bi2O3and a series of selected BixMOygroup 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 the band gap and band edge position of the BixMOygroup materials can be tuned in a wide range in comparison to Bi2O3. Similarly, the light response of BixMOyalso can be broadened from the ultraviolet to the visible light region by adjusting the selection of transition metals. Additionally, the analysis of the effective mass of charge carriers of these materials further confirms their possibility in photocatalytic reaction applications because of the appropriate separation efficiency and mobility of carriers. A selection of experimental investigations on the crystal structure, composition, and optical properties of Bi2O3, BiVO4, and BiFeO3as well as their catalytic performance in the degradation of methylene blue over was also conducted, which agree well with the theoretical predictions.
摘要:
为解决全球能源短缺问题,大规模减少温室气体排放,探索新型高效的光催化剂对于利用可再生资源至关重要。由铋组成的Bi基金属氧化物(BixMOy)半导体,过渡金属,和氧原子表现出改进的光催化活性和产物选择性。可用于BixMOy材料的大量元素组合为合理设计和分离用于特定应用的有希望的光催化剂提供了巨大的组成空间。在这项研究中,通过计算能带结构,我们系统地研究了Bi2O3和一系列选定的BixMOy族材料(BiVO4,BiFeO3,BiCoO3和BiCrO3)的电子和光学性质,基本光学特性特征,载流子的迁移率和分离。清楚地注意到,与Bi2O3相比,BixMOy族材料的带隙和带边缘位置可以在宽范围内调节。同样,通过调整过渡金属的选择,BixMOy的光响应也可以从紫外区扩展到可见光区。此外,对这些材料的电荷载体的有效质量的分析进一步证实了它们在光催化反应应用中的可能性,因为它们具有适当的分离效率和载体的迁移率。