Prediction of 2D heterostructure GaSe/YGaS₃ for highly efficient photocatalytic water splitting

Photocatalytic water splitting technology stands out in the field of green hydrogen production due to its environmental friendliness and broad prospects, becoming a key force in promoting environmental sustainability and efficient energy utilization. The core of this study lies in the exploration of ultra-efficient catalysts. Based on this, we have meticulously constructed a type-II band-aligned GaSe/YGaS₃ heterostructure and conducted an in-depth analysis of its photocatalytic performance through detailed first-principles calculations. Notably, the built-in electric field within the YGaS₃ monolayer can surpass the bandgap threshold (>1.23 eV) set by traditional photocatalytic water splitting theory, thereby significantly enhancing the utilization efficiency of solar energy. The research results indicate that, compared to individual GaSe and YGaS₃ monolayers, the GaSe/YGaS₃ heterostructure exhibits a significantly enhanced optical absorption coefficient. Specifically, its corrected solar-to-hydrogen efficiency has increased by 356% and 103%, respectively, reaching an impressive 34.82%. More excitingly, after applying biaxial tensile strain, this efficiency is further elevated to 36.30%. These remarkable characteristics not only highlight the immense potential and broad application prospects of the GaSe/YGaS₃ heterostructure in the field of photocatalytic water splitting but also lay a solid scientific foundation and provide valuable experimental guidance for the future development of innovative, high-performance photocatalysts.