Enhanced photocatalytic performance of Bi-doped TiO2 under sunlight and UV light: mechanistic insights and comparative analysis.

Bismuth-doped metal oxides exhibit favourable photocatalytic features when exposed to both sunlight and UV light. In this approach, Bi⁰/TiO₂ and Bi⁺³/TiO₂ photocatalysts were prepared and their structural and optical properties are analysed using various characterization techniques. These developed photocatalysts were further tested for the photocatalytic elimination of Nitrobenzene in UV light and sunlight and compared with the performance of bare TiO₂. The catalyst Bi⁺³/TiO₂ performed better in UV light with 72.31% degradation, and 4.74 × 10^-6 mol.litre^-1.min^-1 initial rate of reaction. However, when exposed to sunlight, Bi⁰/TiO₂ outperformed with 73.85% degradation, and 4.63 × 10^-6 mol.min^-1 initial rate of reaction. This significant increase in photocatalytic activity of Bi⁰/TiO₂ under sunlight could be accredited to increased light harvesting and enhanced efficiency in charge carrier separation, both of which were made possible by bismuth-induced surface plasmon resonance.