Synthesis and Characterization of Copper Oxide Composite and Study of Composite Mediated Photo-Oxidative Degradation of Methylene Blue under Visible Light

Copper oxide composite was prepared from copper (II) acetate. Characterization of composite was performed by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), FT-IR Spectroscopy and X-ray diffractometry. According to the findings of SEM the particle size was within the range from 450 nm to 550 nm. Band gap energy was determined by reflectance measurement and value was found to be 4.21 eV. From the result of EDS, it appears that the composite contains only Cu and O atoms. Result of XRD confirms that the composite contains CuO, Cu₂O and metallic Cu. FTIR spectrum of composite supports the presence of Cu₂O. Adsorptive and catalytic properties of composite were studied using Methylene blue as adsorbent. Photo-oxidative degradation of MB was investigated in the suspension of composite in separate experiments at different pH ranging from 2.5 to 5.5 under visible light. Low pH range from 2.5 to 3.5 is most effective for degradation. This was explained by proposing a cyclic mechanism which suggests the conversion of Cu₂²⁺ to Cu²⁺ and vice versa. 95.5% of MB was found to degrade when 5×10^-5 M solution of MB was irradiated for three hours in 100 mL suspension of composite having concentration 1gL^-1 at pH 2.5.