ZHANG Yuanjie， LI Jinkai， LIU Zongming 

School of Materials Science and Engineering， University of Jinan， Jinan 250022， China

Abstract

Objective Hydroquinone is a phenolic compound widely used in industry. It is difficult to degrade in the aquatic ecological environment and is harmful to human health. Therefore， constructing a simple and sensitive method for the detection of hydroquinone is of great significant.

Methods In this study， an MOFs-derived Fe-N-C catalyst was synthesized through a simple chemical doping method and hightemperature pyrolysis， using an Fe-ZIF-8 precursor. The physicochemical properties of Fe-N-C were characterized in detail through SEM， TEM， XRD， FTIR， and XPS. The effect of the introducing Fe³⁺ on the enzyme activity of the catalyst was studied. The enzyme-like activity， catalytic mechanism， and kinetic parameters of Fe-N-C were systematically investigated. Based on the enzyme-like activity of Fe-N-C， a colorimetric sensor for the detection of hydroquinone was developed.

Results and Discussion Based on the aforementioned characterization and experimental findings， Fe-N-C exhibited excellent peroxidase-like activity and weak oxidase-like activity. In addition， in the presence of hydrogen peroxide， OPD and ABTS as substrates were also oxidized to yellow and blue products by Fe-N-C， with characteristic absorption peaks at 448 nm and 416 nm， respectively. Additionally， the poisoning experiment with KSCN showed that Fe-Nx was the main active site in Fe-N-C catalyst. The study of the catalytic mechanism confirmed that ·OH， O₂^•− and ¹O₂ were active oxygen radicals playing a major role in the catalytic oxidation of TMB. The catalytic activity of Fe-N-C nanozymes was further studied through steady-state kinetic analysis. The K_m and V_max of Fe-N-C for TMB were 0. 134 mmol/L and 0. 754 × 10^-7 M·s^-1， respectively， while those for H₂O₂ were 16. 535 mmol/L and 2. 533 × 10^-7 M·s^-1， respectively. Finally， the colorimetric sensor detected HQ in a linear range of 0~33 μmol/L with a detection limit of 0. 356 μmol/L. Through anti-interference experiments， the established colorimetric sensing platform showed robust anti-interference ability and selectivity in detecting hydroquinone.

Conclusion The introduction of Fe³⁺ significantly improves the enzyme-like activity of N-C nanomaterials. Fe-N-C exhibits excellent peroxidase-like activity， which can rapidly oxidize the chromogenic substrate 3，3'，5，5'-tetramethylbenzidine（ TMB） to blue. Fe-N_x is the main active site of Fe-N-C nanozymes， and hydroxyl radica（•OH）， superoxide radicals（ O₂^•−） and singlet oxygen（ ¹O₂） are the main reactive oxygen species（ ROS）. Hydroquinone is a strong reducing organic pollutant that can reduce blue oxTMB to a colorless state. Based on this， a sensing platform for colorimetric detection of HQ was constructed. This method has good sensitivity and selectivity for hydroquinone， which expands the application of MOFs-based nanozymes in the field of environmental pollutant detection.

Keywords： nanozyme； metal-organic framework； colorimetric detection； hydroquinone

Get Citation:ZHANG Y J， LIU Z M. MOFs-derived Fe-N-C nanozyme for colorimetric detection of hydroquinone［J］. China Powder Science and Technology， 2024， 30（4）： 128−137.

Received:2024-05-13.Revised:2024-06-11,Online:2024-06-28.

Funding Project:国家自然科学基金项目， 编号： 51402125； 山东省自然科学基金项目， 编号： ZR2020ME045， ZR2020ME046； 济南市“新高 校20条”基金项目， 编号： 2021GXRCO99， T202204。

First Author: 张元杰（1998—），男，硕士生，研究方向为材料与化工，E-mail：zyj1152995056@163. com。

Corresponding Author: 刘宗明（1965—），男，教授，博士，博士生导师，全国高校黄大年式教师团队骨干成员、山东省有突出贡献的中青年专家，研究方向为粉体工程。E-mail：liuzm@ujn.edu.cn 。

DOI：10.13732/j.issn.1008-5548.2024.04.012

CLC No: O657.32； TQ426.97； TB383             Type Code:A

Serial No:1008-5548（2024）04-0128-10