A first-principles study of electronic structure and photocatalytic performance of two-dimensional van der Waals MTe2–As (M = Mo, W) heterostructures. (16th October 2020)

• Record Type: Journal Article
• Authors: Shehzad, Nasir; Shahid, Ismail; Yao, Sai; Ahmad, Sheraz; Ali, Anwar; Zhang, Lixin; Zhou, Zhen
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 51(2020)
• Page Start: 27089
• Page End: 27097
• Publication Date: 2020-10-16
• Subjects: vdW heterostructures -- Type-II band alignment -- Strain effect -- 2D materials -- Photocatalytic water splitting; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.07.052
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: To efficiently produce green energy and to overcome energy crises and environmental issues, photocatalytic water splitting has become the core heart of recent research. Fabricating heterostructures with type-II band alignment can enhance the photocatalytic activity. By first-principles computations, we study Mo(W)Te2 –As van der Waals (vdW) heterostructures as promising photocatalysts for overall water splitting. The bandgap, band edge position and optical properties can be modified by biaxial strain. With appropriate compressive strain of 2% and 3%, the WTe2 –As heterostructures show transition from type-I to type-II band alignment, which could slow down electron-hole pair recombination. Compared with Mo(W)Te2 and As monolayers, the band edge of Mo(W)Te2 –As heterostructures is on favorable positions for straddling the water redox potentials. Moreover, Mo(W)Te2 –As heterostructures fascinatingly show strong absorption peaks in both visible and near ultra-violet region, making them promising candidates for overall water splitting photocatalysts. Graphical abstract: Image 1 Highlights: Mo(W)Te2 –As heterostructures have tunable bandgaps and strong light absorption. Suitable bandgaps and edge positions make them ideal for water splitting. Strain induces type-II band alignment for better photocatalytic activity.