Tunable optoelectronic, thermoelectric, and photocatalytic properties of β-SiTe and SiH monolayers as a photocatalytic water-splitting

One of the most interesting study areas in the renewable energy production is highly efficient water splitting that relies on the solar energy. More promising photocatalysts which can operate under irradiation from visible light are vitally required. Herein, based on the density functional theory, we demonstrated that two-dimensional SiH and beta-SiTe monolayers exhibit indirect bandgap and suitable band edge locations for photocatalytic splitting of water. Using the PBE approach, we found that the bandgap values for the SiH and beta-SiTe monolayer are 2.19 eV and 1.86 eV, respectively. The rectified bandgaps using the HSE06 function for SiH and beta-SiTe were 2.93 eV and 2.43 eV, respectively. Surprisingly, photocatalytic property studies demonstrated that SiH and beta-SiTe monolayers act as efficient photocatalysts for the production of hydrogen. Our outcomes emphasized that the highest peak of the absorption coefficient of SiH monolayer is 17.1 x 104 cm-1 in the UV region specifically at energy 7.90 eV. While beta-SiTe monolayer has two peaks absorption of (13.5 x 104 and 8.1 x 104) cm-1 in the UV region at energies (7.18 and 9.22) eV. The results presented here imply that the SiH and beta-SiTe could be useful in thermoelectric applications and the construction of photovoltaic cells and catalysts.