Green synthesis of magnetic CoFe2O4 nanoparticles as recyclable photo-Fenton catalysts by sol-gel method with the assistance of tamarind fruit extract

Abstract

Nowadays, there is a growing imperative to develop environmentally friendly methods for the synthesis of catalytic materials. This paper presented a synthesis of magnetic photo−Fenton catalysts based on CoFe2O4 nanoparticles using sol−gel method with tamarind fruit extract as an inexpensive and naturally available gel−forming agent. After the gelation process, the samples were calcined at various temperatures (700, 800, 900°C) and characterized by XRD, FE-SEM, EDS, FTIR, VSM, and N2 absorption experiments. Their photo−Fenton catalytic activities were evaluated through the degradation of methylene blue and methyl orange under UVA light or visible light. The results showed that the combination of using tamarind fruit extract during the gelation and the subsequent calcination process effectively facilitated the production of CoFe2O4 nanoparticles with a cubic spinel single-phase structure. These samples not only demonstrated a high photo−Fenton activity for the degradation of both cationic and anionic dyes, but also exhibited impressive magnetic properties, allowing for easy recovery after use. In particular, the calcination temperature emerged as a pivotal factor in governing the distribution of metal ions on the surface as well as the particle size and the specific surface area of catalysts, thereby significantly affecting their activity.