Efficient catalytic degradation of organic pollutants with cupric oxide nanomaterials in aqueous medium

Abstract

In this work, an eco-friendly, facile, and efficient method has been applied for CuO nanostructures (NSs) synthesis using ascorbic acid as capping agent. For surface morphology, FESEM analysis was applied to reveal nanostructure with ~100 nm length, and ~90 nm width morphology which was also supported by TEM images of CuO. Thus obtained CuO NSs resulted in an optical energy having ~1.36 eV band gap obtained from Tauc plots of UV–visible plots because of strong quantum confinement effect of nanoparticles. XRD reveals a monoclinic phase of CuO NSs for which follow the reference JCPDS No. 98–004–3179 (Space group of C 12/c 1) crystal structure with high crystallinity of ~95.94% and crystallite size of ~38 nm. In addition, Williamson-Hall analysis was applied to calculate crystal lattice strain of ~3.01 × 10-3 for CuO catalyst followed by 28.36 m2/g high BET surface area (0.9999 correlation coefficient) having ~14.38 nm average BJH pore size. Furthermore, CuO NSs exhibited ultrafast and high catalytic degradation efficiency of ~90.54% for Allura Red AC dye (AR dye) in 480 s under UV light. The photodegradation kinetics followed a pseudo first-order reaction with rate constant (k) of ~0.0046 s−1 having approximately ~150.65 s of half-life (t1/2) for AR dyes in the aquatic medium as per the Langmuir–Hinshelwood model. As synthesized catalyst, CuO NSs explored good leaf-like morphology with high recycling ability after five degradation cycles of AR dye in aqueous medium.