Nanocubic Copper-Doped SrTiO₃ for Photoreduction of Cr(VI) and Photodegradation of Methyl Violet

Visible light photocatalysis using nanomaterials is a pragmatic approach for efficiently eliminating pollutants as environmental pollution is a major stumbling block. The wide band gap of SrTiO 3 is permuted to an appropriate value by adding a suitable dopant to make it function as a visible light photocatalyst. Nanocubic copper-doped strontium titanate was prepared through a single-pot solvothermal route and tested for its photocatalytic activity. An exceptional 99% photoreduction of Cr(VI) ions to Cr(III) within 15 min and 100% in 25 min and 99% photodegradation of the methyl violet dye within 120 min was observed for the 0.5 CuST sample. First principles density functional theory calculation reveals the reduced band gap of the doped samples due to the introduction of additional energy levels above the valence band edge to be the reason behind the increased photocatalytic efficiency. In addition to this, the three-fold increase in surface area and low recombination rate of charge carriers in the doped nanocubes also favor in enhancing the activity.