Cu2O–TiO2 Composite for Photocatalytic Degradation of Benzene and its derivatives Using Visible Light

Background: Heterostructured nanocomposites have gained huge attention for their catalytic properties lately. A wide array of different visible-light-active photocatalysts (VLAPs) have been extensively studied of the past couple of years to fine tune the band gap of various stable semiconductors. Objective: The current investigation reports the sensitization of TiO2 nanoparticles with nano sized cuprous oxide, a wellstudied p-type semiconductor, which has a relatively narrow band gap ranging between 2.1 eV & 2.6 eV, to obtain a visible light active photocatalyst. Methods: visible-light-active Cu2O–TiO2 nanocomposite synthesized using solvo-thermal technique. The nanocomposite’s structure and size properties were studied using powder diffraction (XRD), electron microscopy (FESEM and HRTEM). Cu2O–TiO2 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 TiO2 was observed due to the introduction of copper ion, and the nanocomposite also retained high surface area of 76.28 m2 /g. The efficiency of the Cu2O-TiO2 nanoparticles degradation is studied both under UV light and under visible. Cu2O-TiO2 nanoparticles have achieved 97 – 99% degradation of benzene, 92 – 97% degradation of toluene and 95 – 98% degradation of chlorobenzene in water. Conclusion: The said Cu2O–TiO2 nanocomposite is photo-active and showed an overall 95% degradation within 2 hours of treatment under the visible region.