Oxygen-vacancy modified TiO2 nanoparticles as enhanced visible-light driven photocatalysts by wrapping and chemically bonding with graphite-like carbon

To gain commendable photocatalysts from inexpensive materials has always been the goal that researchers are struggling for. In this study, an effective visible-light driven composite photocatalyst (TC800) composed of TiO2 nanocrystals and graphite-like carbon was prepared using titanium tetrachloride and glucose as raw materials via the hydrothermal method with subsequent annealing at 800 degrees C. The results show the TiO2 nanocrystals in the prepared photocatalyst are wrapped and chemically bonded with graphite-like carbon. More importantly, oxygen vacancies are successfully introduced into TiO2 nanocrystals. These two aspects, as well as the enhanced graphitization of carbon, make TC800 possess better photocatalytic activity compared to the as-prepared sample without annealing for degrading rhodamine b (RhB) under visible light irradiation. Moreover, when taking the mass of the dye and the corresponding photocatalyst into consideration, the nanocomposites present 4 times higher photocatalytic activity than the previously reported TiO2/non-graphene carbon compounds. Thus, the nanocomposites proposed in this study will be a good alternative in the field of visible-light driven photocatalysis, and this study also provides further insights into the modification of TiO2.