Cu2O-TiO2 Composite for Photocatalytic Degradation of Benzene and its Derivatives Using Visible Light

Background: Heterostructured nanocomposites have gained massive attention for their catalytic properties lately. A wide array of different visible-light-active photocatalysts (VLAPs) have been extensively studied over the past couple of years to fine-tune the bandgap of various stable semiconductors. Objective: The current investigation reports the sensitization of TiO 2 nanoparticles with nano-sized cuprous oxide, a well-studied p-type semiconductor, which has a relatively narrow bandgap ranging between 2.1 eV & 2.6 eV, to obtain a visible light active photocatalyst. Methods: Visible-light-active Cu 2 O–TiO 2 nanocomposite was synthesized using solvothermal technique. The nanocomposite’s structure and size properties were studied using powder diffraction (XRD), and electron microscopy (FESEM and HRTEM). Cu 2 O-TiO 2 nanocomposite was tested on benzene, toluene and chlorobenzene in contaminated water, under UV and under visible light, for effective implementation in photocatalytic degradation of volatile organic contaminants. Results: The said nanocomposite was crystalline and found to be 40–50 nm in size. No apparent change in the crystal lattice of TiO 2 was observed due to the introduction of copper ion, and the nanocomposite also retained a high surface area of 76.28 m2/g. The efficiency of the Cu 2 O-TiO 2 nanoparticles degradation was studied both under UV light and under visible. Cu 2 O-TiO 2 nanoparticles achieved 97 – 99% degradation of benzene, 92 – 97% degradation of toluene and 95 – 98% degradation of chlorobenzene in water. Conclusion: The said Cu 2 O–TiO 2 nanocomposite is photo-active and showed an overall 95% degradation within 2 hours of treatment under the visible region.