Nitrogen-doped carbon enhanced mesoporous TiO2 in photocatalytic remediation of organic pollutants

Controllable synthesis of mesoporous photocatalysts is of great interest for the photocatalytic remediation of organic pollutants from wastewater by sunlight. In this work, we have developed a new photocatalyst with nitrogen-doped carbon (NC) and mesoporous TiO2 (mTiO2) interpenetrating hetero-structure by a sol–gel process combined with an in situ carbonization strategy. The synthesized nanospheres possess a uniform particle size (~ 60 nm), high surface area (~ 108 m2/g), and large pore diameter (~ 2.1 nm). Most importantly, the nanospheres consist of ultrasmall TiO2 nanocrystals (~ 8.2 nm), which are uniformly coated by a thin layer of N-doped carbon. Significantly, the resultant NC/mTiO2 composite nanospheres exhibit a broad light absorption in the range of 200–2000 nm (entire wavelength). When serving as a photocatalyst for organic pollutants degradation, high performance was obtained. Accordingly, the resultant NC/mTiO2 composite nanospheres performed in an excellent manner in the photodegradation of methyl orange, and the total removal efficiency was up to 97.7%, much better than that of commercial P25 (19.8%). Furthermore, the nanocomposite also effectively photodegraded other organic pollutants such as methylene blue (dyestuff) and phenol, respectively. Therefore, the resultant NC/mTiO2 nanocomposites have potential applications in environmental cleanup.