DFT Calculation of Carbon-Doped TiO₂ Nanocomposites

Titanium dioxide (TiO₂) has been proven to be an excellent material for mitigating the continuous impact of elevated carbon dioxide concentrations. Carbon doping has emerged as a promising strategy to enhance the CO₂ reduction performance of TiO₂. In this study, we investigated the effects of carbon doping on TiO₂ using density functional theory (DFT) calculations. Two carbon doping concentrations were considered (4% and 6%), denoted as TiO₂-2C and TiO₂-3C, respectively. The results showed that after carbon doping, the band gaps of TiO₂-2C and TiO₂-3C were reduced to 1.58 eV and 1.47 eV, respectively, which is lower than the band gap of pure TiO₂ (2.13 eV). This indicates an effective improvement in the electronic structure of TiO₂. Barrier energy calculations revealed that compared to pure TiO₂ (0.65 eV), TiO₂-2C (0.54 eV) and TiO₂-3C (0.59 eV) exhibited lower energy barriers, facilitating the transition to *COOH intermediates. These findings provide valuable insights into the electronic structure changes induced by carbon doping in TiO₂, which can contribute to the development of sustainable energy and environmental conservation measures to address global climate challenges.