Synthesis and evaluation of MSiO3 (M = Ba, Sr, Mg) for photocatalytic hydrogen generation under UV irradiation

•MSiO3 (M = Ba,Sr,Mg) silicates were successfully synthesized by a combustion method.•MgSiO3 presented the highest hydrogen evolution rate of 688 µmol.g−1.h−1.•Higher MgSiO3 HER performance is related to low charge carriers recombination. Alkaline earth metal silicates, MSiO3 (M = Ba, Sr, Mg), were prepared by combustion synthesis. These silicates were characterized by X-ray diffraction (XRD), Diffuse Reflectance Spectroscopy (DRS), and Photoluminescence (PL) Spectroscopy. Its energy band gaps were estimated from Tauc plots, and used with its atomic electronegativity to approximate the flat band potentials. The silicates were evaluated as photocatalysts in a Hydrogen Evolution Reaction (HER) under UV light irradiation with Sodium Sulfite as a sacrificial agent. MgSiO3 was found to be the most promising photocatalyst, with a hydrogen evolution rate of more than three times the rate of the other alkaline earth silicates and P25 (TiO2).