Type-II C2N/ZnTe Van Der Waals Heterostructure: A Promising Photocatalyst for Water Splitting

Based on density functional theory calculations under the framework of first-principles, the electronic and optical characteristics of C2N/ZnTe van der Waals (vdW) heterostructure are investigated in detail. An inherent type-II band alignment arises in the heterostructure, which possesses a 1.94 eV direct band gap. With light irradiation, the photogenerated electron-hole pairs of heterostructure are separated on different monolayers. This helps to extending the lifetime of carriers. Additionally, the lower effective carrier mass (me*=0.55m0, mh*=0.23m0) is owned for the heterostructure. The heterostructure has suitable band gap and band edge positions, as well as, enhanced visible light absorption capacity, which can facilitate photocatalytic water splitting in acidic conditions. More interestingly, the redox reaction of photocatalytic water splitting can still proceed on the heterostructure after exerting a biaxial tensile strain of 2-6%. These results suggest that C2N/ZnTe vdW heterostructure will be a promising water splitting photocatalyst.