Efficient band structure tuning, charge separation, and visible-light response in ZrS 2 -based van der Waals heterostructures

• Published in: Energy & environmental science 2016, Vol.9 (3), p.841-849
• Main Authors: Zhang, Xirui, Meng, Zhaoshun, Rao, Dewei, Wang, Yunhui, Shi, Qi, Liu, Yuzhen, Wu, Haiping, Deng, Kaiming, Liu, Hongyang, Lu, Ruifeng
• Format: Article
• Language: English
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/C5EE03490F

As a fast emerging topic, van der Waals heterostructures can modify two-dimensional (2D) layered materials with desired properties, thus greatly extending the applications of these materials. Via state-of-the-art first-principles calculations, we systematically study four types of van der Waals heterostructures formed by monolayer graphene, h-BN, g-C 3 N 4 , and polyphenylene on ZrS 2 nanosheets. A direct band gap can be obtained in the graphene/ZrS 2 heterostructure, endowing graphene with the real ability to be applied in nanoelectronics, whereas the van der Waals interactions of graphene significantly broadens the optical absorption of ZrS 2 . The conduction band and valence band of the four heterostructures are contributed by the ZrS 2 layer and the other layer, respectively, meaning good charge separation is achieved. We proposed that the strained h-BN/ZrS 2 and g-C 3 N 4 /ZrS 2 heterostructures satisfy fundamental aspects for photocatalytic water splitting, with the reduction and oxidation levels well inside their band gaps. By forming heterostructures with ZrS 2 , the optical properties of h-BN, g-C 3 N 4 and polyphenylene show a remarkable improvement in the visible-light region. The findings in this study will be of broad interest in van der Waals heterostructure research and in the photocatalysis field.