Solar light assisted degradation of dyes and adsorption of heavy metal ions from water by CuO-ZnO tetrapodal hybrid nanocomposite

We report a facile and economic hydrothermal process for multifunctionally engineered copper oxide/zinc oxide-tetrapods (CuO/ZnO-T) nanocomposite for wastewater treatment. The resultant CuO/ZnO-T nanocomposite possesses high porosity, large surface area, and low band gap. All these properties are advantageous for photocatalyst and adsorbent for dyes and heavy metal ions removal. The morphology of synthesized nanocomposite was characterized using X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller, Fourier-transform infrared spectroscopy, and UV-Visible absorption spectroscopy. The results confirmed the attachment of CuO on the ZnO-T surface, forming a hybrid nanocomposite. The concentration of heavy metal ions was monitored using the atomic absorption spectroscopy technique. The synthesized CuO/ZnO-T nanocomposite was investigated for the decontamination of anionic and cationic dyes, Reactive yellow-145 (RY-145) and Basic violet-3 (BV-3) and heavy metal ions (Chromium (VI) and Lead (II)). The CuO/ZnO-T nanocomposite exhibited superior photocatalytic efficiency (80% RY-145 dye removal and 86% BV-3 dye removal) and adsorption capacity (99% Chromium (VI) removal and 97% Lead (II) removal) as compared to pristine ZnO-T. The mechanism for the reduction of dyes and heavy metal ions was discussed by different kinetics and isotherm models. The current study inferred that CuO/ZnO-T nanocomposite is a potential candidate as a proficient photocatalyst/adsorbent for the removal of various wastewater contaminants. (C) 2020 Elsevier Ltd. All rights reserved.