Efficient VOCs photodegradation through local ion substitution in TiO-C composites derived from MIL-125(Ti).

Volatile organic compounds (VOCs) are the main cause of environmental pollution and numerous respiratory diseases. Most VOCs molecules can be entirely converted into HO and CO by photocatalytic technology without the demand for additional oxidants, making it an ideal choice for air purification. However, for conventional photocatalysts, a smaller specific surface area is not conducive to enriching VOCs molecules on the surface of catalyst. To address this, a functionalized porous C-TiO composite was synthesized by a self-sacrificing template method. The resulting porous carbon layer can serve as an adsorption medium to enrich VOCs molecules, while the photocatalytic reaction occurs on the TiO surface. On the basis of the experimental results, the remarkable properties of the catalysts can be attributed to the doping of carbon atoms into oxygen vacancies (OVs) and the formation of Ti@C bonds. Additionally, the study confirmed that C-TiO possesses abundant surface defects and Ti-OH groups, which can facilitate the rapid generation of •OH groups on the catalyst surface, thus aiding in the catalytic oxidation process of VOCs molecules.