Photocatalytic degradation of textile dyes using β-CD-CuO/ZnO nanocomposite

Photocatalytic degradation of dyes using metal oxides and their composite has become a smart process for detoxification of pollutants from wastewater system. The coupling of metal oxides increases the efficiency due to its broad light absorption, fast dynamic process and natural p-n characteristics. Sol-gel method was selected to prepare the binary nanocomposite Copper Oxide/Zinc Oxide (CuO/ZnO) & its ternary nanocomposite with beta cyclodextrin (beta-CD), beta-CD-CuO/ZnO. The synthesized materials were characterized using PXRD, FT-IR, TEM, TGA-DTA and Uv-Visible spectroscopy. For both the materials photocatalytic performance was studied for of model textile dyes pollutants degradation, malachite green (MG) and methylene blue (MB). The efficiency of the prepared catalysts and degradation mechanism are discussed. The involvement of various active species in degradation process is confirmed by applying suitable scavengers. Further the limitation of electron hole recombination was improved by beta-CD addition. The photocatalytic activity of beta-CD-CuO/ZnO was observed superior to CuO/ZnO catalyst. The degradation efficiency was observed up to 89.15 and 79.90% for MB and MG dyes after 180 min of irradiation using beta-CD-CuO/ZnO. In addition to that, beta-CD-CuO/ZnO has good adsorption tendency because of its hydrophilic exterior and hydrophobic interior cavity due to which they can encapsulate pollutant molecules in cavity.