Efficient photocatalytic hydrogen evolution and CO reduction by HfSe/GaAs and ZrSe/GaAs heterostructures with direct Z-schemes

• Published in: Physical chemistry chemical physics : PCCP 2023-03, Vol.25 (12), p.8861-887
• Main Authors: Wan, Xue-Qing, Yang, Chuan-Lu, Wang, Mei-Shan, Ma, Xiao-Guang
• Format: Article
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp05902a

The elaborate configuration of the heterostructure is crucial and challenging to achieve high solar-to-hydrogen efficiency or CO 2 reduction efficiency . Here, we predict two heterostructures composed of HfSe 2 , ZrSe 2 , and GaAs 3 monolayers. The maximum of 42.71%/35.12% with the heterostructures can be reached with the perfect match between the bandgap and band edges. The configurations of the heterostructures are discovered from 12 possible stacking types of the three monolayers. The formation energy, potentials of band edges, carrier mobilities, and optical absorption were used to identify the feasibility of the CO 2 reduction reaction (CO 2 RR), the hydrogen evolution reaction (HER), and the oxygen evolution reaction (OER). The and based on overpotentials and bandgaps and the Gibbs free energies (Δ G s) are evaluated to quantificationally access the photocatalytic performance of the constructed heterostructures. The results demonstrate that high can be obtained for the solar photocatalytic Z-schemes with the HfSe 2 /GaAs 3 and ZrSe 2 /GaAs 3 heterostructures, and these values can be further enhanced through strain engineering. Moreover, small changes in Δ G s were observed for HER, OER, and CO 2 RR. Therefore, the two heterostructures have excellent performance in photocatalytic hydrogen evolution and CO 2 reduction. The results of the electronic properties revealed that the delicate matching of the projected band edges of the monolayers in the heterostructures is responsible for the high photocatalytic performance. The elaborate configuration of the heterostructure is crucial and challenging to achieve high solar-to-hydrogen efficiency or CO 2 reduction efficiency .