Hydroxyapatite nanoparticles decorated with metal–organic framework, Co-Cu/ZIF@HAp, and evaluation of photocatalytic performance of the prepared nanocomposite in the degradation of organic pollutants

Abstract

In this study, a novel hydroxyapatite (HAp)-based composite, Co-Cu/ZIF@HAp, was constructed through in situ growth and simultaneous sonication followed by magnetic string. Herein, the HAp-based nanocomposite was obtained in which HAp was coated with cobalt–copper bimetallic zeolitic imidazolate framework (ZIF) in one-pot synthesis method. The as-synthesized composite was characterized by PXRD, FTIR, FE-SEM, EDS, HR-TEM, TGA-DTG, XPS, BET, and UV-DRS techniques, which suggested that HAp was well coated with bimetallic ZIF. The prepared composite was utilized as a catalyst in degradation of organic pollutants. Removal of organic pollutants such as organic dyes has become indispensable due to their higher stability, toxicity, and mutagenic nature. Two commonly found organic dyes, namely, Eosin Yellow (EY) and Brilliant Green (BG), were chosen for the investigation of photocatalytic activity of the as-prepared catalyst. The degradation process was carried out under solar radiation, and there was no utilization of any oxidizing and reducing agent. Several parameters such as amount of catalyst dose, initial concentration of the dye solution, and effect of different pH conditions were evaluated for better understanding of photocatalytic performance of Co-Cu/ZIF@HAp composite. Both EY and BG dyes were almost degraded up to 98.3% and 99.5%, respectively, within 50 min by the as-prepared nanocomposite. Also, quenching test was performed that confirmed the formation of superoxide radicals (O2−.) as reactive oxygen species (ROS) in the photodegradation process. The as-synthesized catalyst was repeatedly used for five times to ascertain the stability and reusability of catalyst.