A new 2D ternary GaSeCl monolayer for photocatalytic water splitting: a first-principles study

Two-dimensional (2D) materials have shown great promise as photocatalysts for water splitting because of their unique structural and electronic properties. This study explores the photocatalytic potential of the 2D GaSeCl monolayer using first-principles calculations. The GaSeCl monolayer exhibits thermodynamic, mechanical, dynamic, and thermal stability, making it suitable for practical applications. Electronic structure analysis with the Perdew-Burke-Ernzerhof and hybrid HSE06 functionals reveal that it is a direct band-gap semiconductor with band edge positions well-suited to the redox potentials required for hydrogen evolution and oxygen evolution processes. In addition, the monolayer demonstrates high optical absorption in the visible to ultraviolet range, enhancing its efficiency in solar energy harvesting. Furthermore, the application of biaxial strain allows for precise adjustment of the band gap, band edge alignment, and photocatalytic efficiency of this monolayer. These findings underscore the potential of the GaSeCl monolayer as a robust and efficient photocatalyst for sustainable hydrogen and oxygen production through water splitting.