Montmorillonite immobilized Fe/Ni bimetallic prepared by dry in-situ hydrogen reduction for the degradation of 4-Chlorophenlo

Shuo-Shuo Zhang,Shou-Qing Ni,Xuming Zhuang,Xiaohan Xin,Zhaojie Cui,Liying Ren,Vinothkumar Natarajan,Hongyu Si,Ning Yang,Jinhua Zhan

doi:10.1038/s41598-019-49349-w

Abstract

This study puts forward a new way to produce montmorillonite immobilized bimetallic nickel-iron nanoparticles by dry in-situ hydrogen reduction method in the non-liquid environment, which effectively inhibits the oxidation of iron and nickel during the synthesis process and improves the reactivity of the material. The degradation of 4-Chlorophenol (4-CP) was investigated to examine the catalytic activity of the material. The morphology and crystal properties of the montmorillonite-templated Fe/Ni bimetallic particles were explored by using scanning electron microscopy, transmission electron microscopy, X-ray diffraction studies, and energy dispersive X-ray spectroscopy analysis. Results suggest that Fe and Ni particles were homogeneously dispersed on the montmorillonite. The optimization of Ni content and reduction temperature over the degradation of 4-CP was also studied. The introduction of Ni intensely improved the degradation of 4-CP and reached over 90% when Ni content was 28.5%. The degradation rate increased significantly with the increase of reduction temperature and showed maximum activity at the reduction tempreature of 800 °C. This study offers a new method to fabricate montmorillonite immobilized Fe/Ni bimetallic nanoparticles in the non-liquid environment and the composites exhibited high degradation activity to chlorinated organic compounds.

Highlights

Chlorinated organic compounds (COCs) are one of the most important persistent compounds and have been detected in various environmental matrices
Ion exchange/adsorption method was prepared by the ion exchange between the metal cation and the surface cation of the supporting materials, or the metal cation was adsorbed on the surface of the supporting materials, and the metal ion on the materials was reduced by the strong reducing agent to form the zero-valent particles of the bimetal directly on the supporting material[42,43]. During these syntheses processes, nZVI was oxidized with water, which resulted in reduced activity of Fe/Ni bimetallic particles
Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy were used to characterize the change in physicochemical properties of the Fe/Ni bimetallic system

Summary

Introduction

Chlorinated organic compounds (COCs) are one of the most important persistent compounds and have been detected in various environmental matrices. Montmorillonite is an environmental friendly layered clay mineral with specific surface areas ranging from 700 to 800 m2g−1 35,36 It is widely used as an absorbent for the toxic heavy metals and organic contaminants because of its high surface area, chemical stability, low cost and numerous structural properties[37,38]. Ion exchange/adsorption method was prepared by the ion exchange between the metal cation and the surface cation of the supporting materials, or the metal cation was adsorbed on the surface of the supporting materials, and the metal ion on the materials was reduced by the strong reducing agent to form the zero-valent particles of the bimetal directly on the supporting material[42,43] During these syntheses processes, nZVI was oxidized with water, which resulted in reduced activity of Fe/Ni bimetallic particles. Potential parameters which would affect the dechlorination efficiency of 4-chlorophenol by montmorillonite-templated Fe/Ni bimetal particles were investigated

Methods

Results

Conclusion