Multi-functional fluorinated NiTiO3 perovskites for CO2 photocatalytic reduction, electrocatalytic water splitting, and biomedical waste management

Multi-functional F-doped NiTiO3 structures with high stability were prepared by a template-free hydrothermal method. A multi-technique approach including several physicochemical techniques was employed to describe the morphology, electronic properties, and structural characters. The F-doped NiTiO3 catalyst showed a much higher CO2 to CH4 photocatalytic conversion rate (2.6 μmol g−1 h−1) than pristine NiTiO3 (1.6 μmol g−1 h−1), highlighting the key role of F impurities in suppressing the charge carriers recombination. In addition to the higher efficiency and reusability than Pt/C reference electrode toward electrocatalytic water splitting, a lower Tafel slope was recorded for the F-doped structure (81.2 mV dec−1). This implies significant improvement in the reaction kinetics, arising from the synergistic effects between the F sites and bulk constituents to supply more desired active electronic states. The capability of the structures for the biomedical wastewater (containing the Caco-2 cancer cells) treatment was also explored. According to several biochemical assays, the fluorinated material shows a promising performance against the tumor cells at its IC50 concentration, 0.15 μg/mL, in a typical hospital wastewater. Our results pave the way for developing novel multi-functional photoactive titanate perovskites aiming at future clean energy transition