Design and preparation of carissa edulis fruit extract capped with the NiFe2O4/MK30 and oxidation of the organic pollutants under visible light illumination

Abstract

This study focuses on the synthesis of NiFe2O4 nanoparticles through a green synthesis approach using Carissa edulis fruit extract, which was then anchored onto a montmorillonite (MK30) clay substrate to enhance dye photodegradation. The synthesized nanocomposite was characterized using multiple analytical techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy, BET surface area analysis, vibrating sample magnetometry (VSM), zeta potential measurement, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), and electrochemical impedance spectroscopy (EIS). HR-TEM revealed two distinct morphologies within the composite: cubic and irregular. This study further explored the photocatalytic activity of the composites in degrading contaminants such as rhodamine B and ciprofloxacin. Notably, the NiFe2O4/MK30 composite with 12 % NiFe2O4 loading (12FNM) demonstrated a high potential for generating OH and O−2 radicals, achieving an 89.8 % removal efficiency of Rhodamine B at 10 ppm concentration. Compared with conventional Fenton reactions, the photo-Fenton process achieved a superior removal efficiency of up to 99 %. Radical scavenging studies identified the role of hydroxyl and superoxide radicals in photolysis using benzoquinone, isopropyl alcohol, and EDTA as scavengers. Moving forward, research will focus on developing additional modification strategies to further enhance the photocatalytic efficiency of nickel ferrite.