Photocatalytic degradation of xanthate in flotation plant tailings by TiO2/graphene nanocomposites

• TiO 2 /G photocatalytic catalyst was prepared through a hydrothermal method. • TiO 2 /G catalyst was applied for the treatment of mineral processing wastewater. • 18% TiO 2 /G showed superior photocatalytic performance than TiO 2 . This study has invented a novel composite photocatalytic material of TiO 2 /graphene (TiO 2 /G) via the hydrothermal method. The prepared TiO 2 /graphene (TiO 2 /G) composite catalysts were investigated in detail using various characterisation experiments. The characterisation experiments indicated that the TiO 2 /graphene (TiO 2 /G) nanocomposites were successfully prepared. It can be observed that the TiO 2 nanoparticles were observed uniformly distributing on the graphene oxide (GO) and the prepared TiO 2 /graphene (TiO 2 /G) nanocomposites possess huge specific surface area, small pore size, and low electron-hole pair complexation rate to degrade the pollutants. For the first time, TiO 2 /G is used as a photocatalytic material to treat mineral processing wastewater. Compared to GO and TiO 2 , under simulated light irradiation, the photodegradation efficiency of 18% TiO 2 /G samples reached 97.03% after 100 min. By successfully anchoring TiO 2 on GO, the photoresponse range of TiO 2 /G was broadened (from 200–380 nm to 200–800 nm). The activity was also further improved (after 100 min of simulated light, the photocatalytic efficiency of pure TiO 2 was only 17.88%, and the photocatalytic efficiency of 18% TiO 2 /G was 5.43 times higher than that of pure TiO 2 ). This work advances the development of a potential photo-, photoelectro-systems for the treatment of real mineral processing wastewater.