Facile synthesis of n-ZnO @ p-CuO nanocomposite for water purification enhanced decolorization of methyl orange

Abstract

UV light-driven heterogeneous photocatalytic process has been broadly studied as a favorable technique for decolorization of pollutants present in organic wastewater. Herein, we have refined the ZnO@CuO nanocomposite enhanced UV light-driven photodecolorization process using methyl orange (MO) dye as the exemplary photocatalyst pollutant system. We found that the photocatalytic decolorization rate of methyl orange dye was prominently enhanced by ZnO@CuO nanocomposite, and the efficiency also subsequently had increased. The quality crystalline powder of ZnO@CuO nanocomposite was synthesized by adapting hydrothermal method owing to the conventionality and simplified taxonomy. The resulting powders were characterized to study their structural, morphological and optical properties. XRD patterns disclosed the formation of ZnO@CuO nanocomposite with favorable crystalline quality. High resolution scanning electron microscope and-transmission electron microscope images showed that the spherical morphology of nanorods had formed. The stretching and vibration of chemical bonds of the materials were further certified by FTIR spectroscopy. The strong UV emission peaks were detected and the energy gap of the composite had been found as 3.8 eV. Raman spectroscopy was used as an effectual way to assess purity, crystallinity and local vibrations of the sample. The lower PL intensity specified the restricted or slower recombination rate and higher PL intensity designated a faster recombination rate. Investigations of temperature dependent dielectric property of ZnO@CuO nanocomposite results were also discussed. The photocatalytic contaminant removal efficiency of the heterojunction ZnO@CuO nanocomposite over methyl orange was obtained as 91% under 70 min irradiation of the UV light. The present work gives a hopeful way to achieve ZnO@CuO nanocomposite heterojunction for the eco-friendly application in contaminant water purification.