Facile route to fabricate carbon-doped TiO2 nanoparticles and its mechanism of enhanced visible light photocatalytic activity

High-efficiency photocatalysis requires wide photoresponse range and effective separation of photo-generated charges to fully utilize solar energy. Exploring the simple and cheap methods to synthesize efficient photocatalysts is still a challenging issue. Herein, we report a facile and simple room-temperature hydrolysis method using glucose as carbon source to prepare visible light-active C-doped TiO2 photocatalyst. This approach features low-cost, reliable, and easily upscalable. It is found that C atoms have been incorporated into the interstitial position of anatase TiO2 lattice and distributed homogeneously throughout the surface of TiO2 nanoparticles. The appropriate C doping can greatly improve the separation of photogenerated electron-hole pairs in C-doped TiO2. The C-doped TiO2 samples exhibit enhanced photocatalytic activity with the degradation efficiency under UV and visible light irradiation, which is much faster than that of pure TiO2. The mechanism of the enhanced photocatalytic activity is discussed in detail, which is confirmed by using different scavengers. The work provides a simple and useful way to prepare C-doped wide-gap semiconductors with enhanced photocatalytic activity.