Band gap engineering of Mg-based germanate and stannate oxides for sustainable photocatalysis

Humanitys massive usage of nonrenewable energy resources to meet its energy needs produces serious environmental problems. Photocatalysis process is regarded as one of the most promising alternatives for clean and sustainable future energy due to its cleanliness, inexhaustibility, efficiency, and cost-effectiveness. Perovskite oxide photocatalyst materials have received special attention due to their extraordinary features, including flexibility in chemical composition, bandgap, oxidation, and valence states. Emphasizing that this is the first comprehensive DFT study of MgGeO₃ and MgSnO₃ perovskite oxides specifically investigating the synergistic effect of high applied stress on their multi-physical properties (structural, mechanical, optoelectronic, and photocatalytic) for band gap engineering in the visible light spectrum and water splitting applications. Highlighting the discovery of their indirect bandgap tunability under pressure within the visible range, and their remarkable charge carrier separation efficiency (as evidenced by effective masses and band edge positions) as key novel findings. Stressing the predicted thermodynamic and mechanical stability under these conditions, making them promising candidates for experimental synthesis.