Green Synthesis of Flower-Shaped Copper Oxide and Nickel Oxide Nanoparticles via <i>Capparis decidua</i> Leaf Extract for Synergic Adsorption-Photocatalytic Degradation of Pesticides

oleh: Amna Iqbal, Atta ul Haq, Gabriel Antonio Cerrón-Calle, Syed Ali Raza Naqvi, Paul Westerhoff, Sergi Garcia-Segura

Format: Article
Diterbitkan: MDPI AG 2021-06-01

Deskripsi

Green manufacturing of catalysts enables sustainable advanced oxidation processes and water treatment processes for removing trace contaminants such as pesticides. An environmentally friendly biosynthesis process produced high-surface-area CuO and NiO nanocatalysts using phytochemicals in the <i>Capparis decidua</i> leaf extract, which served as a reductant and influenced catalyst shape. <i>Capparis decidua</i> is a bushy shrub, widely distributed in dry and arid regions of Africa, Pakistan, India, Egypt, Jordan, Sudan, Saudi Arabia. The synthesized CuO and NiO nanoparticles were characterized by UV-vis spectroscopy (UV-vis), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) and thermo-gravimetric analysis/differential thermal analysis (TGA/DTA). The produced nanoparticles were spherical and flower-like in shape and have a characteristic face-centered cubic structure of CuO and NiO. Biosynthesized catalysts were photoactive and degraded recalcitrant pesticide Lambda-cyhalothrin (L-CHT). Photocatalytic degradation of L-CHT was affected by the initial L-CHT concentration, solution pH levels between 5 and 9, and photocatalyst concentration. The L-CHT removal percentage attained by CuO photocatalyst (~99%) was higher than for NiO photocatalyst (~89%). The degradation of L-CHT follows a pseudo-first-order kinetic model, and the apparent rate constant (<i>k</i><sub>app</sub>) decreased from 0.033 min<sup>−1</sup> for CuO to 0.0084 min<sup>−1</sup> for NiO photocatalyst. The novel flower-shaped nanoparticles demonstrated high stability in water and recyclability for removing L-CHT pesticide contamination in water.