2D Ge<sub>2</sub>Se<sub>2</sub>P<sub>4</sub> Monolayer: A Versatile Photocatalyst for Sustainable Water Splitting
Tuan V. Vu, Nguyen N. Hieu, Dat D. Vo, A. I. Kartamyshev, Hien D. Tong, Thuat T. Trinh, Vo Khuong Dien, Zakaryae Haman, Poulumi Dey, Nabil Khossossi
Abstract
This study aims to identify photo-/electrocatalysts that can enhance the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR), which are of utmost importance in electro-/photochemical energy systems, such as solar energy, fuel cells, water electrolyzers, or metal-air batteries. Our study focused on investigating the 2D Ge 2 Se 2 P 4 monolayer and found that it exhibits a bifunctional photocatalyst with a very high solar-to-hydrogen efficiency. The two-dimensional (2D) Ge 2 Se 2 P 4 monolayer has superior HER activity compared to that of most 2D materials, and it also outperforms the reference catalysts IrO 2 (110) and Pt(111) in terms of low overpotential values for ORR and OER mechanisms. Such superior catalytic performance in the 2D Ge 2 Se 2 P 4 monolayer can be attributed to its electron states, charge transfer process, and suitable band alignments referring to normal hydrogen electrodes. Overall, the study suggests that the Ge 2 Se 2 P 4 monolayer could be an excellent bifunctional catalyst for advancing photo-/electrochemical energy systems.