Preparation of nanostructured pyrite with N2 glow discharge plasma and the study of its catalytic performance in the heterogeneous Fenton process

Abstract

Pyrite nanostructures were prepared from pyrite ore particles using a simple and practical plasma treatment process based on the N₂ sputtering technique. The nanostructures were characterized using different techniques, such as XRD, FT-IR, SEM, EDX, XPS, and BET analysis. The performance of the plasma-treated pyrite (PTP) was investigated as a new efficient catalyst for the decolorization of reactive orange 29 (RO29) by the heterogeneous Fenton process in a batch system. 97.6% decolorization was observed in the PTP/H₂O₂ process, which was higher than the 38.4% decolorization efficiency of the untreated pyrite/H₂O₂ process. The effects of the operational parameters on the decolorization efficiency were examined, and the 97.6% decolorization efficiency was obtained with an initial RO29 concentration of 20 mg L⁻¹, H₂O₂ concentration of 3 mM, catalyst dosage of 2 g L⁻¹, pH 5, and reaction time of 90 min. The result obtained from the successive application of PTP in the heterogeneous Fenton processes improved the stability of the catalyst in long-term applications. A plausible degradation pathway of RO29 is proposed based on gas chromatography-mass spectroscopy analysis to explain the improved degradation of RO29 through the PTP/H₂O₂ process.