CN109286026B

CN109286026B - Novel (membrane) electrode catalysis peroxymonosulfate auxiliary constructed photocatalytic fuel cell system

Info

Publication number: CN109286026B
Application number: CN201811065145.4A
Authority: CN
Inventors: 柳丽芬; 张艺臻
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2018-09-13
Filing date: 2018-09-13
Publication date: 2022-01-04
Anticipated expiration: 2038-09-13
Also published as: CN109286026A

Abstract

The invention belongs to the technical fields of environmental catalysis, water purification and energy recovery and utilization, and relates to a silver/zinc oxide nanorod array/foam nickel self-supporting electrode material as an anode, a cobalt ferrite/carbon nanofiber electrode or a cobalt ferrite/carbon nanofiber/ PVDF membrane as cathode to construct novel photocatalytic fuel cell system. Cathode Co ²⁺ catalyzes peroxymonosulfate to generate sulfate radicals and singlet oxygen, which helps to improve the degradation performance of the system; carbon nanofibers improve the conductivity and ORR performance of the material, and improve the power generation effect of the PFC system. The CoF ₂ O ₄ /carbon nanofiber/PVDF membrane cathode introduced membrane filtration into the system to increase the reaction contact between the catalytic material and the pollutant, and increase the catalytic activity. The electrons generated by the self-bias of the system promote the circulation of the active site Co ²⁺ in the cathode material in the system, reduce ion dissolution, and improve the reusability of the electrode; efficient pollutant degradation can be achieved in the presence or absence of illumination.

Description

Novel (membrane) electrode catalysis peroxymonosulfate auxiliary constructed photocatalytic fuel cell system

Technical Field

The invention belongs to the technical field of environmental catalysis, water purification and energy recovery and utilization, and relates to a novel photocatalytic fuel cell system constructed by taking a silver/zinc oxide nanorod array/foamed nickel self-supporting electrode material as a photocatalytic anode and taking a cobalt ferrite/carbon nanofiber/carbon fiber cloth electrode or a cobalt ferrite/carbon nanofiber/PVDF membrane electrode as a cathode, in particular to photoelectrocatalysis and sulfate radical catalytic oxidation degradation.

Background

Because of the increasing severity of the environmental pollution problem, how to rapidly, efficiently and energy-efficiently realize the sewage treatment is a problem that researchers have been exploring. Based on sulfate radicals (SO)₄ ^·-) The treatment technology for oxidizing refractory organic pollutants is an advanced oxidation technology developed in recent years. The sulfate radical-based high-grade oxygen process has strong oxidizing capacity, good stability of the oxidant, multiple activation modes, wide pH application range and self-oxidation of sulfate radicalThe lifetime of the free radical (half-life of 4s) is longer than that of the hydroxyl radical (lifetime of less than 1 mus), which is beneficial to contact with pollutants and degradation. Research shows that Co²⁺The activated peroxymonosulfate system has high activity, researchers develop various cobalt-containing compounds which can efficiently activate peroxymonosulfate but commonly have Co²⁺Large elution amount, poor catalyst stability and the like, and limits the wide application of the catalyst. Therefore, it is urgently needed to develop an efficient, stable and recyclable active catalyst to construct an efficient peroxymonosulfate system.

Under the condition of illumination, a Photocatalytic Fuel Cell (Photocatalytic Fuel Cell) converts chemical energy and absorbed solar energy in organic wastewater into electric energy through photoelectrochemical reaction, and simultaneously achieves the purpose of wastewater degradation. Liu Shanshan et al Bi₂MoO₆ITO as anode, Co₃O₄The carbon fiber cloth is used as a cathode to construct a photocatalytic electrochemical system, and the removal rate of phenol of the system is improved from 6% to 100% after the peroxymonosulfate is added under the condition of externally adding 1.5V bias. (Journal of Catalysis 355(2017) 167-175 contexts). However, the external bias needs to consume electric energy, and the photocatalytic fuel cell system can not only realize the electricity generation output of the system without additional electric energy input. The research on efficient pollutant degradation and efficient power generation is not reported yet.

Disclosure of Invention

The invention aims to provide a novel catalytic peroxymonosulfate-assisted photocatalytic fuel cell system, wherein a cathode is a cobalt ferrite/carbon nanofiber/carbon fiber cloth electrode (CoF) which can efficiently catalyze the peroxymonosulfate reaction₂O₄/CNFs/CC) or cobalt ferrite/carbon nanofiber/PVDF membrane electrode (CoF)₂O₄/CNFs/PVDF); the catalytic peroxymonosulfate is realized to assist the photocatalytic reaction to generate free radicals, the pollutant degradation effect of a system is improved, and meanwhile, the electricity is efficiently generated; cathode Co implementation in self-biasing system²⁺The ion elution is reduced by circulation, and the ion elution can be repeatedly used.

The technical scheme of the invention is as follows:

a novel (membrane) electrode catalysis peroxymonosulfate assisted construction of a photocatalytic fuel cell system comprises a data acquisition system, an aeration system, a circulating system and a reactor; the reactor is a single-chamber or double-chamber quartz reactor, the anode is made of a photocatalytic electrode material, the cathode is made of an electrode material which catalyzes peroxymonosulfate or a membrane electrode material which has an interception function, and the anode and the cathode form a Fermi energy range; the anode is connected with the cathode through an external resistor, and the data acquisition system monitors the power generation of the system in real time; the aeration system is an aeration pump with controllable flow rate, and an aeration head is arranged in the cathode chamber of the reactor; when the cathode is coupled with the membrane electrode material, the water discharged from the cathode membrane is driven by the peristaltic pump to be circularly filtered, so that the circulation of the sewage in the system is realized.

The photocatalytic electrode material is a silver/zinc oxide nanorod array/foam nickel self-supporting electrode material (AgNPs/ZnO NRs/NiF), a zinc oxide nanorod array growing along a zinc oxide crystal layer is prepared on the bottom surface of a foam nickel base by adopting a crystal layer method and a hydrothermal method, silver nano particles are deposited on the surface of the zinc oxide nanorod array through in-situ photoreduction, and the AgNPs/ZnO NRs/NiF is prepared.

The electrode material for catalyzing the peroxymonosulfate is cobalt ferrite/carbon nanofiber/carbon fiber cloth electrode (CoF)₂O₄/CNFs/CC), the preparation steps are as follows: subjecting CoF₂O₄the/CNFs powder is dissolved in a silica sol solution or a DuPont film solution, and CoF₂O₄The concentration of the/CNFs powder is 0.1-0.5 mg/ml;

the electrode material with the interception function and the catalysis of the peroxymonosulfate membrane is a cobalt ferrite/carbon nanofiber/PVDF carbon fiber cloth membrane electrode, and the preparation steps are as follows: subjecting CoF₂O₄The CNFs powder is scraped on the carbon fiber cloth by a phase conversion method to be used as an electrode;

the cobalt ferrite/carbon nanofiber composite PVDF membrane electrode is fixed by a flat membrane component, the membrane water outlet speed is controlled by an external peristaltic pump, and the membrane water outlet is circulated to a reactor to realize membrane circulation;

the addition amount of Peroxymonosulfate (PMS) in the reaction system is 0.1-2mM, and the cathode material catalyzes PMS to generate sulfate radicals, so that the degradation effect of the photocatalytic fuel cell is improved in an auxiliary manner.

The pollutants are degraded in the presence of dark illumination or by the addition of light to a single-side electrode, and the self-bias of the system generates electrons to promote active Co in the cathode material²⁺The circulation in the system reduces the ion dissolution and improves the reutilization property of the electrode.

The invention has the beneficial effects that: the invention uses Ag NPs/ZnO NRs/NiF as a photocatalysis anode, and a cobalt ferrite/carbon nanofiber/carbon fiber cloth electrode (CoF)₂O₄/CNFs/CC) or cobalt ferrite/carbon nanofiber/PVDF membrane electrode (CoF)₂O₄/CNFs/PVDF) as cathode to construct a novel photocatalytic fuel cell system. The system realizes self-bias electricity generation and pollutant degradation, and simultaneously, the cathode material catalyzes peroxymonosulfate to generate sulfate radicals to assist in improving the performance of the fuel cell; self-bias generation of electrons to promote active sites Co in cathode materials²⁺The circulation in the system reduces the ion dissolution and improves the reutilization property of the electrode.

Drawings

FIG. 1 shows that the present invention uses Ag NPs/ZnO NRs/NiF as photo-anode, CoF₂O₄the/CNF/CC is used as a cathode to construct a system for catalyzing the peroxymonosulfate assisted photocatalytic fuel cell (external resistor 2000 omega) to degrade 20mg/L berberine into a diagram (a) and a system power generation diagram (b), and carbon nanofiber cloth is used for replacing cathode and anode materials to construct a comparative system.

FIG. 2 shows that the present invention uses Ag NPs/ZnO NRs/NiF as photo-anode, CoF₂O₄the/CNF/PVDF membrane is used as a cathode to construct a system for catalyzing the peroxymonosulfate assisted photocatalytic fuel cell (external resistor 2000 omega) to degrade 20mg/L berberine into a diagram (a) and a diagram (b) respectively.

Detailed Description

The following further describes a specific embodiment of the present invention with reference to the drawings and technical solutions.

Example 1

Ag NPs/ZnO NRs/NiF as photo-anode, CoF₂O₄The CNF/CC is used as a cathode to construct a catalyst peroxymonosulfate auxiliary photocatalytic fuel cell system for degrading berberine:

ag NPs/ZnO NRs/NiF as photo-anode, CoF₂O₄/CNF/CC is a cathode, a saturated calomel electrode is a reference electrode and is connected with a 2000 omega resistor through a lead, and the bottom of the cathode is aerated. The reaction system is 100ml 10mg/L berberine solution, no electrolyte is needed to be added, the adsorption is carried out for half an hour before the reaction starts, then a 300W xenon lamp is turned on to irradiate, simultaneously 0.05mM PMS is added, and the reaction is carried out for 40 min. Samples of 2.5ml were taken at 5min intervals and absorbance was immediately measured using a spectrophotometer. And voltage data is collected by a voltage data collector in the adsorption and reaction stages of the reaction in the whole process.

The degradation contrast experimental data of the system are shown in (a) in fig. 1, and it can be seen that the degradation rate of the system under the illumination of a 300W xenon lamp for 40min reaches 91%, and the battery potential of the system is about 0.50V under the external 2000 omega resistance; respectively compared with Ag NPs/ZnO NRs/NiF as a photo-anode and a carbon fiber cloth cathode without a catalyst, a carbon fiber cloth anode and CoF₂O₄the/CNF/CC is a cathode, the Ag NPs/ZnO NRs/NiF is a photo-anode, and the CoF₂O₄the/CNF/CC is the best performance of a fuel cell system constructed by the cathode.

Example 2

Ag NPs/ZnO NRs/NiF as photo-anode, CoF₂O₄The method comprises the following steps of constructing a catalytic peroxymonosulfate assisted photocatalytic fuel cell system for degrading berberine by taking a/CNF/PVDF membrane as a cathode:

ag NPs/ZnO NRs/NiF as photo-anode, CoF₂O₄the/CNF/PVDF membrane is used as a cathode, the saturated calomel electrode is used as a reference electrode and is connected with a lead, a 2000 omega resistor is externally connected, and the bottom of the cathode is aerated. The reaction system is 500ml of 10mg/L berberine solution, no electrolyte is needed to be added, the mixture is adsorbed for half an hour before the reaction starts, a 300W xenon lamp is turned on to irradiate, 0.05mM PMS is added at the same time, and the reaction is carried out for 60 min; the cathode membrane is externally connected with a peristaltic pump to accelerate circulation of berberine liquid, 2.5ml of samples are taken every 10min, and the absorbance is immediately tested by a spectrophotometer. And voltage data is collected by a voltage data collector in the adsorption and reaction stages of the reaction in the whole process. In FIG. 2, (a) is a degradation experimental diagram, the degradation rate of the system can reach 86% in 60min, and the potential of the system is about 0.7V under 2000 Ω external resistance.

Claims

1. a novel membrane electrode catalysis peroxymonosulfate-assisted construction of a photocatalytic fuel cell system, is characterized in that, the described novel membrane electrode catalysis peroxymonosulfate-assisted construction of a photocatalytic fuel cell system comprises a data acquisition system, an aeration system , circulation system and reactor; the reactor is a single-chamber or double-chamber quartz reactor, the anode is a photocatalytic electrode material, the cathode is a membrane electrode material with catalytic peroxymonosulfate and interception at the same time, the anode and cathode form Fermi The energy is extremely poor; the anode and the cathode are connected by an external resistance, and the data acquisition system monitors the power generation of the system in real time; the aeration system is an aeration pump with a controllable flow rate, and the aeration head is placed in the cathode chamber of the reactor; the circulation system is a cathode coupling membrane When the electrode material is used, the effluent of the cathode membrane is driven by a peristaltic pump to circulate and filter to realize the circulation of sewage in the system;

The electrode material with catalytic peroxymonosulfate is cobalt ferrite/carbon nanofiber/carbon fiber cloth electrode;

The photocatalytic electrode material is a silver/zinc oxide nanorod array/foamed nickel self-supporting electrode material, and the zinc oxide nanorod array grown along the zinc oxide crystal layer is prepared on the surface of the foamed nickel substrate by a crystal layer method and a hydrothermal method, AgNPs/ZnO NRs/NiF were prepared by in-situ photoreduction deposition of silver nanoparticles on the surface of the zinc oxide nanorod array.

2. The novel membrane electrode catalyzed peroxymonosulfate-assisted construction of a photocatalytic fuel cell system according to claim 1 is characterized in that the electrode material having catalytic peroxymonosulfate is cobalt ferrite/carbon nanofiber/carbon fiber cloth electrode , the preparation steps are as follows: the CoF ₂ O ₄ /CNFs powder is dissolved in a silica sol solution or a DuPont membrane solution, and the concentration of the CoF ₂ O ₄ /CNFs powder is 0.1-0.5 mg/ml.

3. The novel membrane electrode catalyzed peroxymonosulfate assisted construction of a photocatalytic fuel cell system according to claim 1 and 2 is characterized in that, the membrane electrode material with interception and catalysis peroxymonosulfate is cobalt ferrite/carbon nanometer Fiber/PVDF carbon fiber cloth membrane electrode, the preparation steps are as follows: CoF ₂ O ₄ /CNFs powder is scraped on the carbon fiber cloth by the phase inversion method to serve as the electrode.

4. The novel membrane electrode catalyzing peroxymonosulfate-assisted construction of a photocatalytic fuel cell system according to claim 3 is characterized in that, the cobalt ferrite/carbon nanofiber/PVDF carbon fiber cloth membrane electrode is fixed by a flat membrane module, and the membrane emits water. The speed is controlled by an external peristaltic pump, and the membrane effluent is circulated to the reactor to realize membrane circulation.

5. The novel membrane electrode catalyzed peroxymonosulfate-assisted construction of a photocatalytic fuel cell system according to claim 1, 2 or 4 is characterized in that the reaction system peroxymonosulfate is added in an amount of 0.1-2mM, and the cathode material catalyzes PMS Sulfate radicals are generated to help improve the degradation effect of photocatalytic fuel cells; pollutant degradation can be achieved with or without light or with light on one-side electrodes, and the system self-bias generates electrons to promote the active Co ²⁺ in the cathode material. It can reduce the ion dissolution and improve the reusability of the electrode.

6. The novel membrane electrode catalyzed peroxymonosulfate-assisted construction of a photocatalytic fuel cell system according to claim 3, wherein the reaction system peroxymonosulfate addition amount is 0.1-2mM, and the cathode material catalyzes PMS to generate sulfate free radicals. It helps to improve the degradation effect of photocatalytic fuel cells; the degradation of pollutants can be achieved in the presence or absence of light or the addition of light to one-side electrodes, while the self-bias of the system generates electrons to promote the circulation of active Co ²⁺ in the cathode material in the system, reducing the Ion dissolution improves the reusability of electrodes.