▎ 摘 要
Graphene oxide (GO) was synthesized utilizing rice husk (RH) as the starting raw material via a modified Hummers' method. Ground pencil leads were used as a control powder of the starting raw material to monitor the consistency of the synthesis method. TiO2 microspheres were synthesized via a precipitated method using the pluronic F127 solution as the pore template. GO derived from RH (GO-RH) was composited with TiO2 microspheres as GO-RH/TiO2 composites by an impregnation method with weight ratios of 3:1, 2:2, and 1:3. Characterized results revealed GO-RH formed a ternary phase material of graphene oxide, graphite oxide, and silica. A typical microstructure of the calcined TiO2 microspheres was found as the agglomerated anatase nanoparticles. Furthermore, the composites belong to large surface areas and numerous oxygen-containing functionalities on their surfaces. Removal efficiencies of cationic dye methylene blue (MB) from aqueous solutions by the composites, GO-RH and TiO2, were studied under UV illumination for 180 min. Due to the effective combination of adsorption and photodegradation for the MB removal, the composites provided the higher efficiencies (99-100%) faster than those of GO-RH and TiO2 and could be reused at least 4 times. Finally, a mechanism of the MB removal by the composites was proposed.