Photocatalytic activity enhancement of anatase–graphene nanocomposite for methylene removal: Degradation and kinetics

• Anatase–graphene nanocomposite was synthesized by an eco-friendly method.
• Blackberry juice was used as a reducing agent to produce the graphene nano-sheets.
• The nanocomposite was applied as a photocatalyst for the degradation of methylene blue.
• A facile and rapid route was applied for the uniform deposition of anatase on sheets.
• Degradation kinetics in the presence nanocomposite was studied by spectroscopy.

In the present research, the TiO2–graphene nanocomposite was synthesized by an eco-friendly method. The blackberry juice was introduced to graphene oxide (GO) as a reducing agent to produce the graphene nano-sheets. The nanocomposite of anatase–graphene was developed as a photocatalyst for the degradation of methylene blue, owing to the larger specific surface area and synergistic effect of reduced graphene oxide (RGO). The UV spectroscopy measurements showed that the prepared nanocomposite exhibited an excellent photocatalytic activity toward the methylene blue degradation. The rate of electron transfer of redox sheets is much higher than that observed on GO, indicating the applicability of proposed method for the production of anatase-RGO nanocomposite for treatment of water contaminated by cationic dye. The prepared materials were characterized with Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller surface area measurement, scanning electron microscopy and transmission electron microscopy. A facile and rapid route was applied for the uniform deposition of anatase nanoparticles on the sheets. The resulting nanocomposite contained nanoparticles with a mean diameter of 10 nm. A mechanism for the photocatalytic activity of nanocomposite was suggested and the degradation reaction obeyed the second-order kinetics. It was concluded that the degradation kinetics is changed due to the reduction of GO in the presence of blackberry juice.

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