Iron oxides/zeolite X composite derived from rice husk ash: fabrication and physicochemical properties for superior heterogeneous Fenton-like oxidation of crystal violet

BACKGROUND

A straightforward and robust technique to develop a heterogeneous Fenton-like catalyst is demonstrated, involving the incorporation of iron oxides into zeolite X derived from rice husk ash, which improved the removal efficiency for crystal violet (CV) with high dye concentration.

RESULTS

The synthesis of an iron oxides/zeolite X composite (IOZX) was investigated at room temperature with an iron salt to zeolite X ratio of 10 wt%, an ion exchange time of 5 h and 15% NaOH. With a surface area of 312 m² g⁻¹, the obtained IOZX also comprised SiO₂ (40.96%), Al₂O₃ (32.08%), Na₂O (24.07%) and Fe₂O₃ (2.72%). Besides, the uniform distribution of iron oxide particles in the composite was determined by scanning electron microscopy and transmission electron microscopy. IOZX exhibited excellent CV removal performance at concentrations ranging from 200 to 500 mg L⁻¹. After 30 min, 96.87% of CV was removed at the optimal conditions such as pH 7, a catalyst dose of 0.5 g L⁻¹, 10 mmol L⁻¹ H₂O₂ concentration and a 300 mg L⁻¹ CV concentration. The degradation followed the pseudo-first-order kinetic model, with R² close to 0.99. The catalytic activities were effectively retained after 10 reaction cycles, indicating the robust performance of IOZX.

CONCLUSION

The key success of the current work was the formation of an IOZX catalyst derived from affordable and commonly available byproducts, leading to cost reductions and supporting sustainable practices. The synthesized catalyst could be further advanced and potentially applied for the remediation of cationic dye from aqueous solution. © 2025 Society of Chemical Industry (SCI).