CN-119977089-B - Electrode material based on non-heme iron catalyst, and preparation method and application thereof

CN119977089BCN 119977089 BCN119977089 BCN 119977089BCN-119977089-B

Abstract

The invention discloses an electrode material based on a non-heme iron catalyst, and a preparation method and application thereof, and belongs to the field of electrocatalytic water treatment. The material is prepared by taking an electrode material as a substrate, sequentially depositing an auxiliary ligand polymerization layer and a non-heme iron catalyst layer on the substrate, wherein the auxiliary ligand polymerization layer is formed by polymerizing an organic monomer, the non-heme iron catalyst layer is formed by reacting ferrous salt and dopamine to form a precursor, and then performing electrochemical polymerization to obtain the electrode material, and the auxiliary ligand polymerization layer is connected with the non-heme iron catalyst layer through coordination bonds. The invention improves the selectivity of hydrogen peroxide produced by electrocatalytic oxygen two-electron reduction of the electrode material and increases the hydrogen peroxide yield by electropolymerizing the auxiliary ligand polymerization layer and the non-heme iron catalyst on the electrode material. In addition, the non-heme iron catalyst can further generate superoxide radical through regulating and controlling the single electron reduction of oxygen, promote hydrogen peroxide to generate hydroxyl radical, and maintain good electrocatalytic organic pollutant removal efficiency under near neutral conditions.

Inventors

REN HONGQIANG
YANG XUDONG
XIA XINGYU
PAN YAO
DING LILI
WANG JINFENG

Assignees

南京大学

Dates

Publication Date: 20260508
Application Date: 20250321

Claims (9)

1. The electrode material based on the non-heme iron catalyst is characterized in that the electrode material is used as a substrate, an auxiliary ligand polymerization layer and a non-heme iron catalyst layer are sequentially deposited on the substrate, wherein the auxiliary ligand polymerization layer is formed by polymerizing an organic monomer, the non-heme iron catalyst layer is formed by reacting ferrous salt and dopamine to form a precursor, then electrochemical polymerization is carried out, the auxiliary ligand polymerization layer and the non-heme iron catalyst layer are connected through coordination bonds, and the organic monomer is a polymerizable organic monomer with a thiophene ring, a furan ring or a pyrrole ring.
2. The non-heme iron catalyst-based electrode material according to claim 1, wherein the molar ratio of ferrous salt to dopamine in the non-heme iron catalyst layer is 0.14:1-2:1.
3. A method for preparing the non-heme iron catalyst-based electrode material according to claim 1, comprising the steps of: (1) Fully dissolving an organic monomer in an organic solvent, carrying out electro-polymerization in a three-electrode system by a cyclic voltammetry or a potentiostatic polymerization method after deoxidization treatment, and carrying out electro-polymerization on the organic monomer to the surface of an electrode material to prepare the electrode material with an auxiliary ligand polymerization layer; (2) Dissolving dopamine hydrochloride in a solvent, deoxidizing, adding ferrous salt, and fully stirring to prepare a non-heme iron catalyst precursor solution; (3) And (3) taking the non-heme iron catalyst precursor solution as electrolyte, taking the electrode material with the auxiliary ligand polymerization layer as a working electrode, performing electropolymerization in a three-electrode system by a cyclic voltammetry, electropolymerizing the non-heme iron catalyst on the surface of the electrode material with the auxiliary ligand polymerization layer, and fully soaking after the electropolymerization is finished to prepare the electrode material based on the non-heme iron catalyst.
4. The method according to claim 3, wherein in the step (1) and the step (2), the technological parameters of the deoxidizing treatment are that nitrogen is aerated for 10-20min, and the nitrogen flow rate of each liter of solution is 1-10mL/min.
5. The process according to claim 3, wherein in the step (1), the molar concentration of the organic monomer in the organic solvent is 1 to 20mM.
6. The method according to claim 3, wherein in the step (2), the molar concentration of the dopamine hydrochloride in the solvent is 5-10mM, and the solvent is a phosphate buffer solution with a molar concentration of 20-100 mM.
7. The method according to claim 3, wherein in the step (3), the soaking parameter is 5 to 30 hours.
8. Use of the non-heme iron catalyst based electrode material of claim 1 in the field of electro-Fenton degradation of pollutants.
9. The method according to claim 8, wherein the electrode material based on non-heme iron catalyst is used as working electrode, the water body containing pollutant is used as electrolyte, and electrocatalytic degradation reaction is carried out in a three-electrode system.

Description

Electrode material based on non-heme iron catalyst, and preparation method and application thereof Technical Field The invention relates to the field of electrocatalytic water treatment, in particular to an electrode material based on a non-heme iron catalyst, and a preparation method and application thereof. Background Conventional sewage treatment processes cannot effectively remove organic pollutants which are difficult to degrade and have high risks in sewage, and the emission of such pollutants into the environment can bring great health risks. Electrocatalytic techniques can either rely on the strong electron withdrawing capability of the anode to directly oxidize the contaminants or rely on the negative potential of the cathode to indirectly oxidize the contaminants by reducing oxygen to produce reactive oxygen species (e.g., hydroxyl radicals). Electrocatalytic techniques based on anodic direct oxidation are affected by electrode pollution, whereas electrocatalytic techniques based on cathodic indirect oxidation are of great interest due to their high oxidation activity. There are two main pathways for the electrocatalytic reduction of oxygen, including the reduction of four electrons to water and the reduction of two electrons to hydrogen peroxide, and the significant thermodynamic advantage of four electron reduction results in low hydrogen peroxide yields. On the other hand, hydrogen peroxide is difficult to directly remove pollutants due to the low oxidizing property of the hydrogen peroxide, fenton and Fenton-like catalysts can activate the hydrogen peroxide to generate active oxygen species such as hydroxyl free radicals or singlet oxygen, but most of the catalysts are limited in activity by pH, can only keep high activity under acidic conditions, and greatly limit the application of electrocatalytic oxygen activation technology. The existing electro-Fenton technology generates hydrogen peroxide by reducing oxygen through a cathode, and then generates Fenton reaction with hydrogen peroxide generated in situ through exogenous addition of Fe 2+ to generate hydroxyl free radicals with strong oxidability, so that efficient removal of organic pollutants is realized. In the technology, the cathode can be used for reducing oxygen to generate hydrogen peroxide and reducing Fe 3+ to generate Fe 2+, so that the purpose of accelerating Fenton reaction is achieved. However, in the electro-Fenton technology, the yield of hydrogen peroxide is low due to thermodynamic advantages of the oxygen four-electron reaction. In addition, the Fenton reaction activity is drastically reduced under the condition that the pH exceeds 3, and iron sludge is generated to cause secondary pollution. Disclosure of Invention The first object of the present invention is to provide a non-heme iron catalyst-based electrode material having excellent electrocatalytic performance and wide pH adaptability, the second object of the present invention is to provide a method for producing the non-heme iron catalyst-based electrode material, and the third object of the present invention is to provide an application of the non-heme iron catalyst-based electrode material. According to the technical scheme, the electrode material based on the non-heme iron catalyst is prepared by taking the electrode material as a substrate, sequentially depositing an auxiliary ligand polymerization layer and a non-heme iron catalyst layer on the substrate, wherein the auxiliary ligand polymerization layer is formed by polymerizing an organic monomer, the non-heme iron catalyst layer is formed by reacting ferrous salt and dopamine to form a precursor, and then conducting electrochemical polymerization, and the auxiliary ligand polymerization layer is connected with the non-heme iron catalyst layer through coordination bonds. Further, the organic monomer is a polymerizable organic monomer having a thiophene ring, furan ring or pyrrole ring, such as thiophene, furan, pyrrole, 2-nitrothiophene, (S) -N, N-dimethyl-3-hydroxy-3- (2-thienyl) propylamine, N-methyl-2-thiophenemethylamine or 2-thiophenemethylamine, and the like. Further, in the non-heme iron catalyst layer, the molar ratio of the ferrous salt to the dopamine is 0.14:1-2:1, preferably 0.14:1-1:1. Further, the electrode material is graphite. In the invention, the catalysis performance of the non-heme iron catalyst takes iron as an active center, but the interaction between the iron center and oxygen is stronger, so that the formed iron dioxygen species can selectively break O-O bonds, and the generation of superoxide radicals is inhibited. And nitrogen, oxygen or sulfur functional groups in pyrrole rings, furan rings or thiophene rings in the auxiliary ligand polymerization layer can form coordination bonds with iron centers, so that the electron cloud density of the iron centers is enhanced, the stability of Fe-O bonds is weakened, the O-O bonds are reserved, and the generation of superoxide radicals is p