Approaches for enhancing the photocatalytic activities of barium titanate: A review

Barium titanate (BaTiO3), a dielectric/ferroelectric semiconductor with perovskite structures is the most widely used photocatalyst in the field of environmental applications due to its low-cost, chemical stability, and non-toxicity. Different types and forms of BaTiO3 have shown their great potential toward the significant photocatalytic reactions owing to the several beneficial properties, including appropriate band positions, high oxygen vacancies, multiple crystal structures, the feasibility of size and morphology tailoring, spontaneous polarization, rapid migration of photogenerated charge carriers, and band bending. However, the large band gap and recombination of photogenerated charge carriers limit the overall photocatalytic efficiency of BaTiO3. These difficulties can be further overcome by modifying the electronic band structure of BaTiO3 to broaden its absorption to the visible region of the spectrum. Hence, this review encompasses various strategies, including modification of sizes and morphologies of particles by varying the reaction time and synthesis temperature, doping with non-metals/metals, loading with noble metals, and forming heterojunctions for enhancing the photocatalytic activities of BaTiO3-based photocatalysts possessing the effective capability of charge carrier separation, trapping and their transfer to the surface of photocatalyst. Also, this review highlights the photocatalytic applications of BaTiO3-based photocatalysts along with the proposed mechanism in dyes/drugs degradation, H2 production, and bacteria killing.