Study on the preparation and catalytic performance of esterified cotton meal fiber Fe/Cu complexes

Organic dye pollutants is one of the serious pollutants in recent years，which is a major global challenge that threatens human health and sustainable societal development. Therefore, effective efficient removal of organic contaminants from water has thus become a vital issue. As an advanced oxidation process, the Fenton reaction has gained considerable attention owing to its effectiveness in degrading refractory organic pollutants. In this study, a simple sol-gel process was used to prepare carboxymethyl fiber copper‑iron complex (Fe/Cu-CMF) heterogeneous Fenton reaction catalyst by co-coordination with copper (II) and iron (III) using esterification-modified cottonseed meal fiber (CMF) as raw material. The results showed that the Fe/Cu-CMF membrane grafting was successful, and the carboxyl group was successfully introduced into the fiber surface structure by the esterification reaction. The preparation of a carboxylate fiber iron‑copper complex through coordination with Fe 3+ and Cu 2+ was carried out for the degradation of reactive red 195 dye, and its catalytic performance was evaluated. Under light irradiation, Fe/Cu-CMF significantly enhanced dye degradation, achieving a decolorization rate of 95.6% in 50 min. The catalyst exhibited optimal activity at pH 3.0 and maintained high efficiency over five consecutive reuse cycles, with the decolorization rate consistently at 95% without significant loss of activity. The research indicates that Fe/Cu-CMF materials are highly promising for use in technologies aimed at treating organic dye wastewater.