Role of intrinsic dipole on photocatalytic water splitting for Janus MoSSe/nitrides heterostructure: A first-principles study

Publication date: Available online 24 July 2019Source: Progress in Natural Science: Materials InternationalAuthor(s): Wenjin Yin, Bo Wen, Qingxia Ge, Daifeng Zou, Ying Xu, Mingwei Liu, Xiaolin Wei, Mingyang Chen, Xiaoli FanAbstractSearching for visible-infrared solar utilization for photocatalytic water splitting is highly desirable, since most of solar energy is distributed the visible-infrared region. However, it is difficult for a pure system to satisfy both band gap and band edge conditions for water splitting in visible-infrared region. Herein, heterostructure consisting of Janus MoSSe and nitrides XN (X = Al, Ga) is proposed, and the structural and electronic properties are systematically studied by the first-principles calculations. It shows that the AA-stacking heterostructure is more stable than other stacking. The calculated electronic property shows that MoSSe/AlN heterostructures have indirect band gaps in the range of 1.00 eV–1.68 eV, while MoSSe/GaN heterostructures are always direct semiconductors with band gaps of 0.8 eV–1.51 eV. Interestingly, despite the band gaps of MoSSe/XN heterostructures being smaller than 1.23 eV, the band edge positions are always suitable for water splitting, suggesting good activity of these heterostructures in visible-infrared region. This special behavior mainly originates from the intrinsic dipole with the electrons of VBM and CBM distributed on two opposite layers, producing an electrostatic potential differenc...
Source: Progress in Natural Science: Materials International - Category: Materials Science Source Type: research