Band gap engineering of Strontium Titanate (SrTiO3) for improved photocatalytic activity and excellent bio-sensing aptitude

Herein, Strontium Titanate (SrTiO3) has been synthesized through template-free hydrothermal process and annealed at different temperatures (i.e., 300 °C, 500 °C and 700 °C) in a hydrogen atmosphere to modulate its bandgap. XRD, SEM, UV–Vis spectroscopy and PL spectroscopy were used to characterize the samples. The creation of oxygen vacancies has been verified, which contributes significantly to the reduction of the bandgap and the improvement of photocatalytic efficiency. STO annealed at the temperature of 500 °C displayed maximum evolution of 3060 μmol g−1 of hydrogen gas via photocatalytic water splitting and showed 88% and 81% methyl orange (MO) and methylene blue (MB) degradation, respectively. Furthermore, the as-synthesized materials were used for the electrochemical biosensing of ascorbic acid, and STO-500 showed best results achieving the correlation R-square value of 0.9981. The findings of this study will be useful in investigating SrTiO3-photocatalysts in industries and implementing for electrochemical diagnostics.