α-Fe₂O₃/SiO₂/Zr-Ni based MOFs as water stable Fenton-like catalyst for Congo Red degradation and hexavalent chromium adsorption from aqueous solution

The presence of dyes and heavy metals as pollutants in water bodies can cause significant health problems if not treated adequately. This research successfully used Zr-BDC functional material via doping of Ni ions on the surface of α-Fe₂O₃/SiO₂ for Cr(VI) adsorption and Fenton-like CR dye oxidation. The optimized composite-(10) showed superior Cr(VI) adsorption performance with adsorption capacity up to 93.458 mg/g and CR dye degradation performance via Fenton-like oxidation, reaching >98 % under optimal reaction conditions. In addition, the adsorption and degradation process of CR dye via Fenton-like oxidation was proven to be effective in the neutral pH. The adsorption results of Cr(VI) and CR dye were in good agreement with the pseudo second order kinetic model and Langmuir adsorption isotherm. Reusability experiments showed that the relatively high performance could be maintained, indicating the good reusability performance. In addition, phytotoxicity studies show that the products obtained during the Fenton-like system are less toxic than untreated dye solutions. This research not only highlights the correlation between adsorption and degradation, but also offers new insights into the development of functional materials with good water stability and in the process improves their applicability in environmental remediation applications.