Insights into the solar-light-driven photocatalysis of greenly synthesized CoCr2O4 nanoparticles using Azadirachta indica

Abstract

The green synthesis of nanomaterial offers an option for chemical processes, which can harm the ecosystem and human health due to exposure to perilous materials and harsh fabrication scenarios. In the present work, Azadirachta indica leaf extract (AILE) was applied in a green synthesis approach to create cobalt chromite nanoparticles (CoCr₂O₄ NPs). This approach makes the process straightforward, simpler, benign, and cheaper, which requires less effort to produce CoCr₂O₄ NPs. The characterization of CoCr₂O₄ NPs was explored using diverse analytical techniques. According to the XRD diffractograms, CoCr₂O₄ NPs were obtained in the cubic phase. TEM disclosed their pseudo-spherical morphology with a mean diameter of 54.89 nm. The bandgap of CoCr₂O₄ NPs was found to be 2.39 eV, which allows for UV absorption and makes them ideal for effective photocatalysts under sunlight. Conversely, under direct sunlight, the photocatalytic potential of CoCr₂O₄ NPs was examined employing malachite green (MG) dye as a pollutant model. After 90 min, a decomposition of 91.33% was accomplished, revealing pseudo-first-order reaction kinetics. In addition, the influence of H₂O₂, CoCr₂O₄ loading, MG dye concentration, and scavengers on the MG photodegradation was also verified. In a nutshell, this work describes the creation of a CoCr₂O₄ photocatalyst that reveals excellent efficiency, particularly in solar light irradiation, indicating that it may find application in potential wastewater cleanup.

Graphical Abstract