▎ 摘　　要

We used a simple method of graphene oxide (GO) preparation with different oxidation levels, and control the properties of the TiO2 nanocrystals by tuning the content and oxidation degree of GO to enhance the photocatalytic performance. During the hydrothermal reaction, reduction of GO, formation of TiO2 and chemical bonds between TiO2 and reduced graphene oxide (RGO) was achieved simultaneously. Characterization results showed that TiO2 properties such as crystalline grain and particle size could be tailored by the amount of functional groups, and that crystallinity was also controlled by GO degrees of oxidation. TiO2/RGO photocatalysts showed great efficiency of mercury oxidation, which reached 83.7% and 43.6% under UV and LED light irradiation, respectively. The effects of crystalline grain size and surface chemical properties on Hg-0 removal under LED and UV light irradiation were analyzed. In addition, the properties of the photocatalysts before and after UV illumination were investigated, finding that part of Ti-OH on TiO2 surface transformed to Ti-O-Ti. In a nutshell, this work could provide a new insight into enhancing activity of photocatalysts and understanding the photocatalytic mechanism.