P Doping Promotes the Spontaneous Visible-Light-Driven Photocatalytic Water Splitting in Isomorphic Type II GaSe/InS Heterostructure
Wenxue Zhang, Yuefeng Yin, Cheng He
Abstract
The development and design of clean and efficient water splitting photocatalysts is important for the current situation of energy shortage and environmental pollution. A new type of isomorphic GaSe/InS heterostructure is constructed, and the optoelectronic properties were studied through first-principles calculations. The results show that GaSe/InS vdW heterostructure is a type II semiconductor with a band gap of 2.09 eV. However, through the analysis of the energy band edge position and Gibbs free energy change of water splitting, it is found that the GaSe/InS heterostructure is difficult to undergo overall water splitting. Therefore, nonmetallic element P doping is considered, the established P-doped GaSe/InS (P-GaSe/InS) heterostructure could maintain the type II band arrangement, and under acidic conditions, P-GaSe/InS heterostructure could spontaneously undergo overall water splitting thermodynamically. Furthermore, the low exciton binding energy of P-GaSe/InS heterostructure highlights better light absorption performance. Therefore, these findings indicate that P-GaSe/InS heterostructure is a promising photocatalyst in overall water splitting.