NiO-NiFe2O4-rGO Magnetic Nanomaterials for Activated Peroxymonosulfate Degradation of Rhodamine B

Xiaochen Xu,Yanfang Li,Guoquan Zhang,Fenglin Yang,Ping He

doi:10.3390/w11020384

Xiaochen Xu, Yanfang Li + Show 3 more

Open Access

https://doi.org/10.3390/w11020384

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Abstract

Magnetic spinel ferrites that act as heterogeneous catalysts and generate powerful radicals from peroxymono-sulfate (PMS) for the degradation of organic pollutants have received much attention in recent years due to the characteristic of environmental benefits. In this study, NiO-NiFe2O4-rGO magnetic nanomaterials were synthesized using a calcinated Ni-Fe-LDH-rGO precursor. The morphology, structure, and chemical constitution were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), transmission electron microscope (TEM), N2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometer (VSM). The catalytic performance of NiO-NiFe2O4-rGO nanoparticles was thoroughly evaluated for peroxymonosulfate (PMS) activation and its removal of rhodamine B (RhB) from water. The influence of different process parameters on the RhB degradation efficiency was examined. Further, the catalytic stability was evaluated. Under optimized conditions, the NiO-NiFe2O4-rGO/PMS system was very efficient; RhB fully degraded after 40 min at room temperature. Quenching experiments and electronic paramagnetic resonance (EPR) results suggested that SO4−· and OH· were the main active species in the degradation process. Moreover, NiO-NiFe2O4-rGO catalyst was stable without any apparent activity loss after three cycling runs.

Highlights

In the industrial production processes, sustainable development is a major issue.The most contaminated textile wastewater stream, dyeing discharge, was selected for dedicated treatment using advanced oxidation processes (AOPs) [1]
We focused on the synthesis of NiO-NiFe2 O4 -reduced graphene oxide (rGO) and its magnetic nanomaterials using a hydrothermal route
We investigated the removal effect of rhodamine B (RhB) in the range of 0.2–2.0 g·L−1 of NiO-NiFe2 O4 -rGO at

Summary

Introduction

In the industrial production processes, sustainable development is a major issue. The most contaminated textile wastewater stream, dyeing discharge, was selected for dedicated treatment using advanced oxidation processes (AOPs) [1]. The basic principle of the AOPs is to generate highly active intermediate species (i.e. OH·, O2 − ·, and SO4 − ·) for mineralization of refractory organic pollutants, water pathogens, and disinfection by-products. Due to the high oxidative potential of hydroxyl radicals (OH·), which appear in AOPs, many organic compounds, including dyes, can be decomposed; OH· have high second-order reaction rate constants with most organic molecules, including both bulk organic matter and micropollutants [2]. The bulk organic matter is abundantly present in secondary effluent and acts as an important scavenger for OH·, which has become much less available for reaction with organic micropollutants [3,4].

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