Two-dimensional InBrSe monolayer: A highly efficient photocatalyst for water splitting

Good photocatalysts is one of the best approaches to harvest the solar energy. The performance of two-dimensional photocatalytic materials depends on their distinctive geometric structure and optical absorbed efficiency. However, the tendency to recombine the photogenerated electron-hole pairs in many two-dimensional materials limits their photocatalytic performances. Here, we find a novel FeOCl-type InBrSe monolayer of superior photocatalysis through first-principle calculations. Its electron mobility is 42.53 times greater than that of hole along y-axis, indicating that anisotropic mobilities limit the recombination of photogenerated electron-hole pairs. Its solar to hydrogen efficiency (27 %) exceeds the critical value (10 %) of commercial application of photocatalytic water splitting. Moreover, its suitable band edges are advantageous for spanning water redox potentials to achieve photocatalytic processes. Under biaxial strains, it obtains large optical absorption coefficients within the visible light range. Additionally, it exhibits favorable thermal, mechanical and structural stability, indicating that it is feasible for real-life experimental synthesis. Thus, we predict that the InBrSe monolayer is a promising candidate for photocatalyst.