The Electronic Structure and Optical Properties of Two‐Dimensional BiOX–YO3 (X = Cl, Br, and I; Y = Mo, W) Heterostructures. Issue 11 (3rd July 2019) - Tang, Zhen‐Kun
Abstract : Semiconductor photocatalysts have received a lot of attention because of their wide range of applications in solving energy and environmental problems. In this work, the electronic structure and optical properties of two‐dimensional (2D) heterostructures of bismuth oxyhalides (BiOX, X = Cl, Br, I) and transition‐metal oxides (YO3, Y = Mo, W) are studied by density functional theory. The results reveal that the 2D BiOX–YO3 heterostructures are semiconductors with band gaps of 0–1.41 eV. Electronic structure analyses indicate that the valence band maximum (VBM) and conduction band minimum (CBM) of BiOX–YO3 are spatially separated and reside in the BiOX and YO3 layers, respectively. The electron effective masses of BiOI–YO3 (Y = Mo, W) heterostructures, especially BiOI–WO3, are significantly lower than those of BiOI and YO3 . BiOI–YO3 (Y = Mo, W) heterostructures exhibit a good absorption in the visible light region. The enhanced optoelectronic properties of BiOI–YO3 are found to be related to the comparably large lattice mismatches between BiOI and YO3 . The ultra‐low electron effective mass and good visible absorption of the BiOI–WO3 heterostructure make it a promising candidate for the high‐efficient photocatalyts for water‐splitting. Abstract : BiOX–YO3 (X = Cl, Br, I; Y = Mo, W) heterostructures exhibit good absorption in the visible light region. The electron effective masses of the BiOI–YO3 heterostructures, especially BiOI–WO3, are lower than those of the YO3 monolayer components. Besides, the valence band maximum (VBM) and conduction band minimum (CBM) of BiOX–YO3 are separate and reside in the BiOX and YO3 layers, respectively.