DFT Calculation of Carbon-Doped TiO 2 Nanocomposites.

Titanium dioxide (TiO 2 ) 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 CO 2 reduction performance of TiO 2 . In this study, we investigated the effects of carbon doping on TiO 2 using density functional theory (DFT) calculations. Two carbon doping concentrations were considered (4% and 6%), denoted as TiO 2 -2C and TiO 2 -3C, respectively. The results showed that after carbon doping, the band gaps of TiO 2 -2C and TiO 2 -3C were reduced to 1.58 eV and 1.47 eV, respectively, which is lower than the band gap of pure TiO 2 (2.13 eV). This indicates an effective improvement in the electronic structure of TiO 2 . Barrier energy calculations revealed that compared to pure TiO 2 (0.65 eV), TiO 2 -2C (0.54 eV) and TiO 2 -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 TiO 2 , which can contribute to the development of sustainable energy and environmental conservation measures to address global climate challenges.