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

Abstract

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 °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.