A nanozyme-based enhanced system for total removal of organic mercury and SERS sensing

Hao Liu; Yue Guo; Yunxin Wang; Huidan Zhang; Xiaowei Ma; Sisi Wen; Jing Jin; Wei Song; Bing Zhao; Yukihiro Ozaki

doi:10.1016/j.jhazmat.2020.124642

A nanozyme-based enhanced system for total removal of organic mercury and SERS sensing

J Hazard Mater. 2021 Mar 5:405:124642. doi: 10.1016/j.jhazmat.2020.124642. Epub 2020 Nov 21.

Authors

Hao Liu¹, Yue Guo¹, Yunxin Wang², Huidan Zhang¹, Xiaowei Ma¹, Sisi Wen¹, Jing Jin¹, Wei Song³, Bing Zhao¹, Yukihiro Ozaki⁴

Affiliations

¹ State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
² Jilin Provincial Center for Disease Control and Prevention, 3145 Jingyang Street, Changchun 130062, PR China.
³ State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China. Electronic address: weisong@jlu.edu.cn.
⁴ School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 660-1337, Japan; Toyota Physical and Chemical Research Institute, Yokomichi, Nagakute, Aichi 480-1192, Japan.

PMID: 33301972
DOI: 10.1016/j.jhazmat.2020.124642

Abstract

Total removal of organic mercury in industrial wastewater is a crucially important task facing environmental pollution in the current world. Herein, we demonstrate the fabrication of Au-NiFe layered double hydroxide (LDH)/rGO nanocomposite as not only an efficient nanozyme with oxidase-like activity but also an efficient surface-enhanced Raman spectroscopy (SERS) substrate to determine organic mercury, with the minimum detection concentration as low as 1 × 10^-8 M. According to the binding energy of X-Ray photoelectron spectrometer (XPS) and the free radicals of electron paramagnetic resonance (EPR) spectra, the mechanism of catalytic enhanced degradation is the production of Au-amalgam on Au surface, accelerating the electron transfer and the generation of O₂^•- radicals from oxygen molecules and •CH₃ radicals from the methyl group in MeHg to participate the oxidase-like reaction. Furthermore, the Au-NiFe LDH/rGO nanocomposite is able to degrade and remove 99.9% of organic mercury in two hours without the secondary pollution by Hg²⁺. In addition, the material can be used for the multiple degradation-regeneration cycles in actual applications, which is significant in terms of the environmental and economic point of view. This work may open a new horizon for both highly sensitive detection and thorough degradation of organic mercury in environmental science and technology.

Keywords: Nanozyme; Oxidase-like reaction; Removal of organic mercury; Surface-enhanced Raman scattering.

Publication types

Research Support, Non-U.S. Gov't