High photocatalytic activity of carbon doped TiO2 prepared by fast combustion of organic capping ligands†
Abstract
Carbon doping has been widely applied to modify TiO2 to improve photocatalytic activity and initiate visible light activity. Using oleylamine wrapped TiO2 nanomaterials as precursor, carbon doped TiO2 photocatalysts have been synthesized by control of heating ramp rates and temperatures in air. Optical absorption of all these photocatalysts are extended to visible light, and photogenerated electron–hole separation is enhanced by carbon doping. Especially, those prepared by fast combustion of oleylamine ligands exhibit excellent photocatalytic activity and visible light activity for hydrogen production. EPR analysis demonstrates that more oxygen vacancies present in carbon doped TiO2 with high activity. This indicates that oxygen vacancies may play key roles in photocatalytic water splitting. Fast heating process may have offered an oxygen-poor atmosphere in which oxygen vacancies are favoured.