Solvothermal Preparation of Zinc Oxide/Reduced Graphene Oxide Composites for Rapid Removal of Methylene Blue.

Zinc oxide/reduced graphene oxide composites with various morphologies and properties were prepared via a one-step solvothermal process. The formation of zinc oxide and reduction of graphene oxide were simultaneously accomplished. These as-obtained samples showed high performance in removing methylene blue from aqueous solution. Solvent could play an important role in tuning the morphologies of the zinc oxide and the efficiency of the final composites. Composites prepared in acetone showed the highest removal efficiency, compared with those prepared in water and ethanol. Loading content of the reduced graphene oxide could affect the performance as well. With the increase in the content of the reduced graphene oxide, the as-prepared samples showed enhanced performance gradually. The as-prepared composite showed certain stability, with a maximum recyclability of 5 times for efficient removal. The effective removal of target dye turned out to be the result of the combination of physical adsorption and photo-catalysis.