Type-II AsP/Sc2CO2 van der Waals heterostructure: an excellent photocatalyst for overall water splitting. (21st September 2021)

• Record Type: Journal Article
• Authors: Guo, Haojie; Zhu, Bao; Zhang, Fusheng; Li, Hui; Zheng, Kai; Qiu, Jian; Wu, Lingmei; Yu, Jiabing; Chen, Xianping
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 65(2021)
• Page Start: 32882
• Page End: 32892
• Publication Date: 2021-09-21
• Subjects: Photocatalytic water splitting -- The first-principles calculations -- AsP/Sc2CO2 heterostructure -- Type-II -- Biaxial strain; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.07.125
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this work, we explore the application potential of AsP/M2 CO2 (M = Sc, Zr) van der Waals heterostructures in photocatalytic water splitting through the first-principles calculations. The calculated results show that AsP/Zr2 CO2 heterostructure possesses an unfavorable type-Ⅰ band alignment, whereas AsP/Sc2 CO2 exhibits a desirable type-Ⅱ band alignment, which is beneficial for separating the photogenerated electron-hole pairs. Also, the band edge positions of AsP/Sc2 CO2 heterostructure stride the redox potential of water, ensuring favorable reaction kinetics. Besides, the strong optical absorption of AsP/Sc2 CO2 heterostructure in both visible and ultraviolet regions (especially up to 10 −6 cm −1 at about 250 nm) makes it possible to utilize solar energy effectively. Meanwhile, AsP/Sc2 CO2 heterostructure has an exciton binding energy as low as 0.09 eV, which quantitatively illustrates the high separation efficiency of photogenerated charge carrier. Thus, the type-Ⅱ band alignment, suitable band edge position, strong light absorption, and low exciton binding energy together indicate that AsP/Sc2 CO2 heterostructure is a potential photocatalytic material. In addition, the obvious redshift phenomenon in the optical spectrum of AsP/Sc2 CO2 heterostructure shows that biaxial strain can improve its light capture capability. Also, the interconversion between type-Ⅱ and type-Ⅰ can be achieved by applying different strains. All these findings suggest that the novel AsP/Sc2 CO2 heterostructure has significant application prospects in next-generation photovoltaic and photocatalytic devices. Highlights: AsP/Sc2 CO2 heterostructure good optical absorption in visible and ultraviolet regions. The lower exciton binding energy of AsP/Sc2 CO2 heterostructure confirms the effective carrier separation. The conversion of heterostructure type and the improvement of optical properties are realized under biaxial strain.