CN113896275A

CN113896275A - Photoelectrocatalysis reactor

Info

Publication number: CN113896275A
Application number: CN202111210287.7A
Authority: CN
Inventors: 马新培; 卢耀斌; 栾天罡
Original assignee: Guangdong University of Technology
Current assignee: Guangdong University of Technology
Priority date: 2021-10-18
Filing date: 2021-10-18
Publication date: 2022-01-07

Abstract

本发明公开了一种光电催化反应器，包括：导电阳极和导电阴极；导电阳极包括导电玻璃，导电玻璃上负载二氧化钛、碳三氮四和碳量子点；导电阴极包括导电材料和催化剂，催化剂包括碳黑、乙炔黑、石墨、石墨烯、铂、铁基催化剂、铁锰二元催化剂、铁锰铜三元催化剂中的至少一种。本发明以二氧化钛纳米管阵列为底，掺杂碳三氮四和碳量子点的导电阳极，缩减二氧化钛的能带间隙；从而提高了光电催化反应器的可见光响应和光效率，可见光响应得以增强；本发明所使用的阴极比常用铂箔或铂丝阴极比表面积更大，从而使光电子转移效率提高，光生电子空穴对复合率降低，整体光电催化效率得到提高。The invention discloses a photoelectric catalytic reactor, comprising: a conductive anode and a conductive cathode; the conductive anode comprises conductive glass, on which titanium dioxide, carbon trinitride and carbon quantum dots are supported; the conductive cathode comprises a conductive material and a catalyst, and the catalyst comprises At least one of carbon black, acetylene black, graphite, graphene, platinum, iron-based catalyst, iron-manganese binary catalyst, and iron-manganese-copper ternary catalyst. The invention takes the titanium dioxide nanotube array as the base, and the conductive anode doped with C3N4 and carbon quantum dots reduces the energy band gap of the titanium dioxide, thereby improving the visible light response and light efficiency of the photoelectric catalytic reactor, and the visible light response is enhanced; The cathode used in the invention has a larger specific surface area than the common platinum foil or platinum wire cathode, thereby improving the photoelectron transfer efficiency, reducing the recombination rate of photogenerated electron-hole pairs, and improving the overall photoelectric catalytic efficiency.

Description

Photoelectrocatalysis reactor

Technical Field

The invention belongs to the field of photoelectric materials, and particularly relates to a photoelectric catalytic reactor.

Background

With the increasing population, agricultural production and industrial scale of human society and the development of life style towards high demand, environmental pollution and energy crisis are two major problems facing the development of human society. The photoelectrocatalysis technology, particularly the photocatalysis fuel cell technology, which is used as one of the waste water resources, takes light as a driving force, can fully utilize chemical energy stored by organic compounds in the waste water, achieves the aims of treating sewage and avoiding energy waste, and is one of effective means for solving the environmental problems and energy crisis.

In recent years, self-driven photoelectrocatalysis systems have shown great advantages in reducing the rate of recombination of photogenerated hole-electron pairs. In contrast to conventional externally powered photoelectrocatalytic systems, self-driven photoelectrocatalytic can utilize chemical energy in a compound to self-generate electricity. When the photo-anode is exposed to light, photoelectrons are excited from a valence band of the photo-anode to a conduction band, a built-in bias potential between the photo-anode and the cathode drives the photoelectrons to reach a cathode side through an external circuit, and photo-generated holes with strong oxidizing property are left in the valence band of the photo-anode, so that persistent organic pollutants in a water body are degraded into water and carbon dioxide.

Since the performance of the photoelectrocatalysis catalysis system mainly depends on the photocatalyst, most of the research is focused on the development of the photoanode material at present. The existing photoelectrocatalysis system, especially the self-driven photoelectrocatalysis system of visible light catalysis has no less research on the cathode, and the cathode in most photoelectrocatalysis systems is selected from platinum foil or platinum wire. However, there are two disadvantages to using platinum foil or wire as the cathode: firstly, the specific surface area of a platinum foil or platinum wire cathode is small, so that the overall efficiency of a photoelectrocatalysis system is limited; secondly, because the solubility of oxygen in the electrolyte is low, extra aeration is often needed to enhance the transfer of oxygen in the photoelectrocatalysis reaction, so that the photoelectrocatalysis efficiency is improved, but the requirement of aeration inevitably increases the operation cost of a photoelectrocatalysis system. In addition, no research has been made on the use of fenton-like air diffusion cathodes as cathodes in visible-light responsive self-driven photo-catalytic systems.

Disclosure of Invention

In order to overcome the problems of low photoelectric catalytic efficiency and high operation cost in the prior art, the invention aims to provide a photoelectric catalytic reactor, and the invention aims to provide application of the photoelectric catalytic reactor.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a photoelectrocatalytic reactor comprising: a conductive anode and a conductive cathode; the conductive anode comprises conductive glass, and titanium dioxide, carbon, nitrogen, carbon and quantum dots are loaded on the conductive glass; the conductive cathode comprises a conductive material and a catalyst, wherein the catalyst comprises at least one of carbon black, acetylene black, graphite, graphene, platinum, an iron-based catalyst, a ferro-manganese binary catalyst and a ferro-manganese-copper ternary catalyst.

Preferably, the photoelectrocatalysis reactor also comprises a light source with the light intensity of 70-95mW/cm²(ii) a More preferably, the light intensity is 75-90mW/cm²(ii) a Still more preferably, the light intensity is 80-85mW/cm²(ii) a The light source simulates visible light.

Preferably, the photoelectrocatalysis reactor also comprises an electrolyte solution, a titanium sheet/wire and an organic glass reactor; the conductive anode and the conductive cathode are respectively arranged in an electrolyte solution containing organic matters, an external circuit is connected through a titanium sheet/titanium wire, the conductive anode is excited under a light source to generate photoelectrons, and photo-generated electrons are driven by a cathode-anode potential difference to migrate to the conductive cathode through the external circuit, so that a loop is formed, and the photoelectric catalytic reactor degrades the organic matters and generates electric energy.

Further preferably, in the photoelectrocatalysis reactor, the distance between the conductive cathode and the conductive anode is 1-4 cm; still further preferably, the distance between the conductive cathode and the conductive anode is 1-3 cm; still more preferably, the distance between the conductive cathode and the conductive anode is 2 cm.

Further preferably, in the photoelectrocatalysis reactor, a light source irradiates the conductive anode, and the distance between the light source and the conductive anode is 1-6 cm; still further preferably, the distance between the light source and the conductive anode is 2-5 cm.

Further preferably, in the photoelectrocatalysis reactor, the electrolyte solution is Na₂SO₄、NaCl、NaNO₃Or one of phosphate buffer solutions.

Further preferably, in the photoelectrocatalysis reactor, the concentration of the electrolyte solution is 10-600 mmol/L; still more preferably, the concentration of the electrolyte solution is 20 to 500 mmol/L.

Preferably, the photoelectrocatalysis reactor can be externally connected with a power supply, and the external current is 0.5-10 mA; further preferably, the external current is 1-9mA, and the external current can be 1mA, 3mA, 6mA or 9 mA; still more preferably, the applied current is 3 mA.

Preferably, the preparation method of the photoelectrocatalysis reactor and the conductive anode comprises the following steps:

1) conducting hydrothermal reaction on conductive glass and titanium-containing solution to obtain loaded TiO₂The conductive glass of (1);

2) will support TiO₂Carbonizing the conductive glass to obtain TiO₂/C₃N₄An electrode;

3) adding TiO into the mixture₂/C₃N₄And immersing the electrode into a carbon quantum dot solution for treatment to obtain the photoelectrode.

Further preferably, in step 1), the preparation method of the conductive anode further comprises a pretreatment step of conductive glass (FTO); still more preferably, the pretreatment step is as follows: conducting glass (FTO) is ultrasonically cleaned by using isopropanol, ultrapure water and acetone; more preferably, the mass ratio of the isopropanol to the ultrapure water to the acetone is 1:1:1, and the ultrasonic cleaning time is 0.5-1.5 h.

Further preferably, in step 1) of the preparation method of the conductive anode, conductive glass (FTO) is placed on the surface of the titanium-containing solution to perform hydrothermal reaction.

Further preferably, in the step 1) of the preparation method of the conductive anode, the titanium-containing solution is obtained by mixing hydrochloric acid and tetrabutyl titanate; still more preferably, the mass ratio of hydrochloric acid to tetrabutyl titanate is (12-14): 1; more preferably, the mass ratio of hydrochloric acid to tetrabutyl titanate is 13: 1.

further preferably, in the step 1) of the preparation method of the conductive anode, the reaction temperature of the hydrothermal reaction is 120-180 ℃; still more preferably, the reaction temperature of the hydrothermal reaction is 140-; more preferably, the reaction temperature of the hydrothermal reaction is 150 ℃.

Further preferably, in the step 1) of the preparation method of the conductive anode, the reaction time of the hydrothermal reaction is 4-6 h; still more preferably, the reaction time of the hydrothermal reaction is 4.5-5.5 h; more preferably, the reaction time of the hydrothermal reaction is 5 hours.

Further preferably, in the step 2) of the preparation method of the conductive anode, TiO is loaded₂The conductive glass is placed on the surface of a carbon source solution for carbonization; even more preferably, the conductive glass has TiO₂One surface of the carbon source is contacted with a carbon source solution for carbonization.

Further preferably, in step 2) of the preparation method of the conductive anode, the carbon source solution is a dicyandiamide solution.

Further preferably, in the step 2) of the preparation method of the conductive anode, the carbonization temperature is 500-600 ℃; the carbonization time is 2-4 h; still further preferably, the carbonization temperature is 550 ℃; the carbonization time is 3 h; the carbonization may be performed in a muffle furnace.

Further preferably, in step 3) of the method for preparing a conductive anode, TiO is used₂/C₃N₄Immersing the electrode in a Carbon Quantum Dot (CQDs) solution, and drying at 50-70 ℃ for 8-12 h; still more preferably, drying is carried out at 60 ℃ for 10 h.

Further preferably, in step 3), the preparation method of the conductive anode comprises the following steps: mixing a glucose solution and a sodium hydroxide solution, performing ultrasonic treatment, and adjusting the pH to be neutral to obtain a CQDs solution; still more preferably, the molar mass ratio of glucose to sodium hydroxide is 1 (0.5-1.5); the ultrasonic treatment condition is 30-50kHz, 220-260W; still more preferably, the molar mass ratio of glucose to sodium hydroxide is 1: 1; the ultrasonic treatment conditions were 40kHz, 240W.

Preferably, in the photoelectrocatalysis reactor, the conductive cathode catalyst comprises one or more of carbon black, acetylene black, graphite and graphene; further preferably, the conductive cathode catalyst comprises graphite; the conductive cathode is an air diffusion cathode.

Preferably, in the photoelectrocatalysis reactor, when the conductive cathode catalyst comprises graphite, the graphite loading is 2-2.9mg/cm²。

Preferably, in the photoelectrocatalysis reactor, the conductive cathode catalyst comprises one or more of carbon black, acetylene black, graphite and graphene and platinum; further preferably, the conductive cathode catalyst comprises platinum and carbon black, and the mass ratio of the platinum to the carbon black is 1: (1-2); still more preferably, the conductive cathode catalyst comprises platinum and carbon black in a platinum to carbon black mass ratio of 2: 3; the conductive cathode is a platinum carbon electrode.

Preferably, in the photoelectrocatalysis reactor, when the conductive cathode catalyst comprises platinum, the amount of the platinum loaded catalyst is 0.3-0.7mg/cm²(ii) a Further preferably, the amount of platinum as the supported catalyst is 0.4 to 0.6mg/cm²(ii) a Still more preferably, the amount of platinum as the supported catalyst is 0.5mg/cm²。

Preferably, in the photoelectrocatalysis reactor, the conductive cathode catalyst comprises one or more of carbon black, acetylene black, graphite and graphene and one or more of an iron-based catalyst, a ferro-manganese binary catalyst and a ferro-manganese-copper ternary catalyst; further preferably, the conductive cathode catalyst comprises one or more of carbon black, acetylene black, graphite and graphene and a ferro-manganese-copper ternary catalyst; still further preferably, the conductive cathode catalyst comprises a graphite and iron-manganese-copper ternary catalyst, and the mass ratio of the graphite to the iron-manganese-copper ternary catalyst is (1-3): 1; more preferably, the conductive cathode catalyst comprises graphite and a ferro-manganese-copper ternary catalyst, and the mass ratio of the graphite to the ferro-manganese-copper ternary catalyst is 2: 1; the conductive cathode is a fenton-like air diffusion cathode.

Preferably, in the photoelectrocatalysis reactor, when the conductive cathode catalyst comprises a three-way catalyst of iron, manganese and copper, the mass ratio of iron, manganese and copper in the three-way catalyst of iron, manganese and copper is (2-4): 1: (7-9); further preferably, the mass ratio of iron, manganese and copper in the iron-manganese-copper ternary catalyst is 3: 1: 8.

preferably, in the photoelectrocatalysis reactor, the mass ratio of the conductive material of the conductive cathode to the catalyst is 1: (0.1-0.8), and more preferably, the mass ratio of the conductive material to the catalyst is 1: (0.1-0.6); still further preferably, the mass ratio of the conductive material to the catalyst is 1: (0.125-0.5).

Preferably, in the photoelectrocatalysis reactor, the conductive cathode further comprises a binder; further preferably, the mass ratio of the conductive material to the binder is 1: (0.2-8); still further preferably, the mass ratio of the conductive material to the binder is 1: (0.4-6); still more preferably, the mass ratio of the conductive material to the binder is 1: (0.5-5).

Further preferably, in the photoelectrocatalysis reactor, the adhesive of the conductive cathode is one or more of polytetrafluoroethylene, perfluorosulfonic acid polymer (Nafion), polydimethylsiloxane and polyvinylidene fluoride; still more preferably, the adhesive is one of polytetrafluoroethylene, perfluorosulfonic acid type polymer (Nafion), and polydimethylsiloxane; still more preferably, the binder is one of polytetrafluoroethylene and perfluorosulfonic acid type polymer (Nafion).

Preferably, in the photoelectrocatalysis reactor, the preparation method of the conductive cathode comprises the following steps:

s1, coating the conductive material with PDFE to obtain waterproof carbon cloth;

and S2, mixing the catalyst and the adhesive, and coating the mixture on waterproof carbon cloth of S1 to obtain the conductive cathode.

Further preferably, in the preparation method of the conductive cathode, the conductive material in step S1 is a carbon cloth, and one side of the carbon cloth has conductive carbon black; still more preferably, in step S1, PDFE (polytetrafluoroethylene) coating is performed on the side of the carbon cloth having the conductive carbon black.

Further preferably, in the method for preparing the conductive cathode, the conductive material PDFE is coated and then dried in step S1; further preferably, the drying temperature is 200-400 ℃, the drying time is 5-15min, and the drying times are 1-3; more preferably, the drying temperature is 300 ℃, the drying time is 10min, and the drying times are 2 times; drying may be carried out in a muffle furnace.

Further preferably, in the method for manufacturing the conductive cathode, the catalyst and the binder are mixed and coated on the side of the waterproof carbon cloth having no waterproof surface in step S2.

The invention also provides the application of the photoelectrocatalysis reactor in organic matter degradation; further preferably, the organic matter comprises one or more of carbamazepine, diazepam, triclosan and PPCPs; still further preferably, the concentration of the organic matter is 0.5-4 mg/L; more preferably, the concentration of the organic substance is 1 mg/L.

The invention also provides application of the photoelectrocatalysis reactor in the field of power generation.

The invention has the beneficial effects that:

(1) the recombination rate of the photo-generated electron-hole pairs is reduced. The invention takes a titanium dioxide nanotube array as a base, and a conductive anode doped with carbon, nitrogen, carbon and quantum dots is used for reducing the energy band gap of titanium dioxide; thereby improving the visible light response and the light efficiency of the photoelectrocatalysis reactor, and enhancing the visible light response. The conductive cathode used in the invention is loaded with catalysts such as carbon black, acetylene black, graphite, graphene, platinum, an iron-based catalyst, a ferro-manganese binary catalyst, a ferro-manganese-copper ternary catalyst and the like, and the surface area is larger, so that the photoelectron transfer efficiency is improved, the recombination rate of photo-generated electron hole pairs is reduced, and the overall photoelectrocatalysis efficiency is improved.

(2) The overall operation cost of the photoelectrocatalysis system is reduced. The air-permeable layer on the back of the conductive cathode used in the invention can be communicated with air, and when the reaction is carried out, an oxygen concentration difference can be formed, so that oxygen is provided for the reactor, an additional aeration device is not needed, and the operation cost of photoelectrocatalysis is greatly reduced.

(3) The photocatalytic performance is improved. Under the irradiation of visible light, the carbon quantum dots of the photoelectrode can accelerate the charge movement on the surface of the electrode, so that the overall photocatalytic performance is improved; in addition, when the conductive cathode catalyst material selects carbon-based and platinum catalysts, the Fermi level of the photoelectrode is higher than the oxidation-reduction potential of the cathode, so that self-bias voltage is formed, no external voltage is needed, and only under the action of the self-bias voltage, electrons formed by photoexcitation of the photoelectrode can be transmitted to the cathode, so that the recombination of photo-generated electron hole pairs of the photoelectrode is effectively inhibited, and the photoelectrocatalysis is better; to produce H₂The O-based carbon-based and platinum catalyst can increase the current generated by the photoelectrocatalysis reactor, inhibit the recombination rate of photoproduction holes and electrons, and divide the photoproduction electrons and the holesThe separation effect is good, so that the degradation of pollutants in water can be accelerated, and the electricity generation efficiency can be increased.

(4) The degradation rate of organic pollutants is improved. The degradation rate of the organic matters is related to the content of active radical hydroxyl free radicals generated by the system, the oxidation of the hydroxyl free radicals can degrade the organic matters, and when the conductive anode is coupled with the cathode capable of generating the hydroxyl free radicals, the effect of degrading pollutants by the cooperation of the cathode and the anode can be achieved, so that the degradation rate of the organic pollutants in water is improved. Produce H₂O₂The carbon-based catalysts mainly comprise conductive carbon black, acetylene black, graphite, graphene and the like, and the effect of degrading pollutants in water by anode photocatalysis and cathode photocatalysis is achieved by the combined action of hydrogen peroxide with oxidability generated by a cathode and an anode; in the cathode to produce H₂O₂The catalyst and the metal catalyst form an in-situ electro-Fenton-like reaction, so that active oxides with oxidizing property, such as hydroxyl free radicals, superoxide free radicals and the like, are generated, and the degradation of organic pollutants in water is accelerated.

Drawings

Fig. 1 is a schematic diagram of a photoelectrocatalytic reactor 1 provided in example 1.

FIG. 2 is a graph of the removal rate of carbamazepine by direct photolysis, photocatalysis, and photoelectrocatalysis of example 1.

Fig. 3 is a graph of the removal rate of different concentrations of carbamazepine from the photoelectrocatalytic reactor 1 provided in example 1.

Fig. 4 is a graph comparing the first order kinetic rate constants of the removal effect of the photoelectrocatalytic reactor 1 provided in example 1 for different concentrations of carbamazepine.

Fig. 5 is a graph of the power density of the photoelectrocatalytic reactor 1 provided in example 1 at different concentrations of carbamazepine.

FIG. 6 is a graph of the removal rate of carbamazepine of examples 2-3.

FIG. 7 shows the removal rate of carbamazepine from example 3 at different applied currents.

Fig. 8 is a graph of the removal rate of different concentrations of carbamazepine from the photoelectrocatalytic reactor 4 provided in comparative example 1.

Fig. 9 is a power density curve of comparative example 1.

Detailed Description

The present invention will be described in further detail with reference to specific examples. The starting materials or apparatuses used in the examples and comparative examples were obtained from conventional commercial sources or may be obtained by a method of the prior art, unless otherwise specified. Unless otherwise indicated, the testing or testing methods are conventional in the art.

Example 1

TiO of this example₂/C₃N₄The preparation method of the CQDs photoelectrode comprises the following steps:

(1)TiO₂/C₃N₄preparing an electrode: conductive glass FTO (7 omega/m)²Diameter 34mm, thickness 2.2mm) with isopropanol: ultrapure water: and (3) carrying out ultrasonic cleaning for 1h by using acetone (the volume ratio is 1:1: 1). Mixing 40mL of 36.5 wt% concentrated hydrochloric acid with 40mL of ultrapure water, adding 1.32mL of tetrabutyl titanate, uniformly mixing, putting the mixed solution and the ultrasonically cleaned conductive glass FTO into a hydrothermal reaction kettle, enabling the FTO conductive glass to face upwards, reacting at 150 ℃ for 5 hours, taking out the conductive glass, washing, naturally drying, and putting the mixture and 2g of dicyandiamide into a 30mL ceramic crucible, wherein the dicyandiamide is positioned at the bottom, the conductive glass is positioned at the upper part, and the conductive surface faces downwards. Then putting the mixture into a muffle furnace, and heating at 550 ℃ for 3 hours to prepare TiO₂/C₃N₄And an electrode.

(2) 0.05mol of glucose was dissolved in 50mL of ultrapure water, and 50mL of a 1mol/L NaOH solution was added. The mixed solution was then sonicated for 2h (40kHz, 240W) to turn the solution brown, and the resulting brown solution was made neutral with HCl to give an aqueous solution of CQDs. TiO prepared in the step (1) is added₂/C₃N₄Immersing the electrode in CQDs solution and drying at 60 deg.C for 10 hr to obtain TiO₂/C₃N₄CQDs photoelectrode.

The preparation method of the platinum-carbon electrode of the embodiment is as follows:

(1) coating PDFE (polytetrafluoroethylene) on one surface of a carbon cloth (4cm multiplied by 8cm) with conductive carbon black to form a waterproof surface, wherein the coating amount of the PDFE is about 1mL, drying, putting the carbon cloth into a muffle furnace, and repeating for 2 times at 350 ℃ for 10min to obtain waterproof carbon cloth;

(2) 15mg of 47.5% Pt catalyst (Pt loading 0.5 mg/cm) was weighed out²) And 45mg of carbon black are put into a plastic bottle, 6-8 glass particles are added, 50 mu L of deionized water is added, the mixture is shaken for 20s, 400L of 5 wt% Nafion solution and 200 mu L of isopropanol are added, and the mixture is uniformly coated on the other side (opposite to the waterproof side) of the waterproof carbon cloth. When coating, the platinum carbon electrode is obtained by coating layer by layer, the action is as light as possible, and the next layer can be coated after the dry layer is coated until the material in the plastic bottle is used up.

TiO prepared in this example₂/C₃N₄The CQDs photoelectrode and the platinum carbon electrode are connected to two sides of the organic glass reactor, and the cathode and the anode are connected through the titanium wire to form a closed loop, so that the photoelectrocatalysis reactor 1 can be obtained, as shown in figure 1.

Photoelectrocatalytic reactor 1 degradation of Carbamazepine (CBZ) experiment:

at room temperature, the electrolyte is 50mmol/L phosphate buffer solution, the initial pH is 7, the degradation time is 300min, the visible light is visible light, and the light intensity is 80-85mW/cm²1mg/L carbamazepine was subjected to a degradation experiment with carbamazepine in a photoelectrocatalytic reactor 1. Simultaneously setting direct photolysis, photocatalysis and TiO₂/C₃N₄Photoelectrocatalysis (reduction of TiO in a photoelectrocatalysis reactor₂/C₃N₄CQDs photoelectrode was replaced by TiO prepared in example 1₂/C₃N₄Electrode, the other reaction conditions were the same); the conditions of the direct photolysis reaction are as follows: placing 1mg/L carbamazepine into a container, and only irradiating visible light to calculate the removal effect of the carbamazepine after 300min of reaction; the photocatalytic reaction conditions are as follows: 1mg/L carbamazepine, TiO₂/C₃N₄CQDs photoelectrode is placed in a container, and visible light irradiates TiO₂/C₃N₄CQDs photoelectrode, the effect of carbamazepine removal after 300min reaction was calculated and the results are shown in FIG. 2.

As shown in fig. 2, the removal rate of 1mg/L carbamazepine in the photoelectrocatalysis reactor 1 reaches 75.29% in 300min, the direct visible light photolysis removal rate is 3.88%, and the visible light photocatalysis removal rate is 5.87%; from the figure2 in the name of TiO₂/C₃N₄The photoelectrocatalysis removal rate is 62.87 percent, and the TiO content is₂/C₃N₄Effect ratio of a photoelectrocatalysis reactor 1 constructed by CQDs photoelectrode to TiO₂/C₃N₄The electrode-constructed photo-reactor is more preferable because CQDs can accelerate the movement of surface charges of the anode. The self-driven photoelectrocatalysis reactor with visible light response generates internal bias under the action of the photoelectricity anode and the platinum carbon cathode, accelerates the separation of photoelectrons and cavities, and effectively improves the removal efficiency of the photoelectrocatalysis reactor on pollutants on the premise of not improving energy consumption.

At room temperature, the electrolyte is 50mmol/L phosphate buffer solution, the initial pH is 7, the degradation time is 300min, the visible light is visible light, and the light intensity is 80-85mW/cm²Different initial concentrations of carbamazepine were subjected to degradation in the photoelectrocatalytic reactor 1. The test results are shown in FIG. 3. In the photoelectrocatalysis reactor 1, the degradation effect of the initial concentration of carbamazepine after 300min reaction is obviously better than that of 0.5mg/L, and by further comparing the first-order kinetic rate constants of the carbamazepine, such as the graph in FIG. 4, and referring to the concentration of carbamazepine in conventional municipal sewage of 0.001-0.1mg/L, the initial concentration of carbamazepine of 1mg/L can be obtained to be the optimal initial concentration of the embodiment.

Based on the degradation of carbamazepine of different initial concentrations in the example in the photoelectrocatalytic reactor 1, the open circuit voltage and the short circuit current were measured and compared with the power density curve of the photoelectrocatalytic reactor 1 in different initial concentrations of carbamazepine, as shown in fig. 5. FIG. 5 is a graph showing power density curves at initial concentrations of 0.5ppm, 1ppm, 2ppm and 4ppm in the case of a phosphate buffer solution of 50mmol/L and an initial pH of 7, in which the open circuit voltage (Voc) ranges from 455.8 to 541.2mV and the short circuit current density (Jsc) ranges from 0.02337 to 0.02443mA · cm, in which cathodes and anodes were connected together by a titanium wire and irradiated with visible light^-2The maximum energy density is 1.7557-2.1202 μ W-cm^-2The filling factor range is 0.1604-0.1719, and the photoelectric conversion efficiency of the photoelectric reactor is better according to the filling factor. The experimental results also show that the initial concentration is 1mg/L cardThe open circuit voltage and short circuit current of the westernine are both greater than the other three initial concentrations.

Example 2

The air diffusion cathode of this example was prepared as follows:

(2) 0.09g of graphite was added to a 10mL plastic centrifuge tube, then 100. mu.L of deionized water, 800. mu.L of a 5 wt% perfluorosulfonic acid solution, 400. mu.L of isopropanol, and 12 glass beads were measured. Vortex for 5min to mix them evenly. And (3) quickly coating the mixture on the other side (opposite to the waterproof side) of the waterproof carbon cloth, standing for 24 hours and airing to obtain the air diffusion cathode.

TiO obtained in example 1₂/C₃N₄The CQDs photoelectrode and the air diffusion cathode prepared by the embodiment are connected to two sides of the organic glass reactor, and the cathode and the anode are connected through a titanium wire to form a closed loop, so that the photoelectrocatalysis reactor 2 can be obtained.

Photoelectrocatalysis reactor 2 degradation Carbamazepine (CBZ) experiment:

at room temperature, the electrolyte is 50mmol/L phosphate buffer solution, the initial pH is 7, the light intensity is 80-85mW/cm²The initial concentration of carbamazepine is 1mg/L, and the reaction is carried out in the photoelectrocatalysis reactor 2 for 300 min. The removal rate of carbamazepine was 28.9%, as shown in fig. 6.

Example 3

The preparation method of the fenton-like air diffusion cathode of the present example is as follows:

(2) weighing 0.18g of iron-manganese-copper ternary catalyst, wherein the mass ratio of iron, manganese and copper is 3: 1: 8, 0.09g of graphite was added to a 10mL plastic centrifuge tube, then 100. mu.L of deionized water, 800. mu.L of a 5 wt% perfluorosulfonic acid solution, 400. mu.L of isopropanol were measured, and 12 glass beads were added. Vortex for 5min to mix them evenly. And (3) quickly coating the mixture on the other surface (opposite to the waterproof surface) of the waterproof carbon cloth, standing for 24 hours and airing to obtain the Fenton-like air diffusion cathode.

TiO obtained in example 1₂/C₃N₄The CQDs photoelectrode and the Fenton-like air diffusion cathode prepared by the embodiment are connected to two sides of the organic glass reactor, and the cathode and the anode are connected through a titanium wire to form a closed loop, so that the photoelectrocatalysis reactor 3 can be obtained.

Photoelectrocatalytic reactor 3 degradation of Carbamazepine (CBZ) experiments:

at room temperature, the electrolyte is 50mmol/L phosphate buffer solution, the initial pH is 7, the light intensity is 80-85mW/cm²The initial concentration of carbamazepine is 1mg/L, and the reaction is carried out in the photoelectrocatalysis reactor 3 for 300 min. The removal rate of carbamazepine was 64.43%, as shown in figure 6. The degradation effect of the photoelectrocatalysis reactor 3 is better than that of the photoelectrocatalysis reactor 2.

When different impressed currents (1mA, 3mA, 6mA and 9mA) are connected between the cathode and the anode of the photoelectrocatalysis reactor 3, the degradation of carbamazepine can be promoted. The electrolyte is 50mmol/L phosphate buffer solution, the initial pH is 7, the initial concentration of carbamazepine is 1mg/L, and 1mg/L carbamazepine in the reactor can be completely degraded within 100min under the condition of adding 3mA current. Figure 7 shows the carbamazepine removal rate at different applied currents.

Comparative example 1

Construction of the photoelectrocatalytic reactor 4

The photoelectrocatalysis reactor 4 of this comparative example was the same as that of example 1 except that a platinum carbon electrode of example 1 was replaced with a common commercially available platinum wire electrode.

Photoelectrocatalysis reactor 4 degradation Carbamazepine (CBZ) experiment:

at room temperature, the electrolyte is 50mmol/L phosphate buffer solution, the initial pH is 7, the degradation time is 300min, and 1mg/L carbamazepine is subjected to degradation experiment in a photoelectrocatalytic reactor 4. The removal rate of 1mg/L carbamazepine at 300min is 44.48%, as shown in FIG. 8, FIG. 8 also shows that the photoelectrocatalytic reactor 1 of the embodiment 1 has the electrolyte of 50mmol/L phosphate buffer solution at room temperature, the initial pH is 7, the degradation time is 300min, the removal rate of 1mg/L carbamazepine at 300min is 75.29%, and the effect of the platinum-carbon electrode is better than that of the platinum wire electrode. This is because the platinum-carbon electrode manufactured in example 1 has waterproof and air permeability after the back surface of the carbon cloth is treated, and oxygen in the air can be pumped into the reactor due to pressure difference during the reaction, so that it is not necessary to provide oxygen like the conventional platinum wire or platinum foil electrode, which saves the cost; in addition, the platinum-carbon coating area of the platinum-carbon electrode coated with the catalytic layer surface is large, so that the effect of coupling the platinum-carbon electrode is better than that of coupling the platinum wire electrode.

In a phosphate buffer solution with 50mmol/L electrolyte, the initial pH is 7, the visible light is visible light, and the light intensity is 80-85mW/cm²And under the reaction condition that the degradation time is 300min, a removal experiment is carried out on 1mg/L carbamazepine by using the photoelectrocatalysis reactor 1 and the photoelectrocatalysis reactor 4, the obtained power density curve is shown in the attached figure 9, and the effect of using the platinum-carbon electrode is better than that of using a platinum wire electrode by using the power density curve shown in the attached figure 9.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A photoelectrocatalytic reactor, comprising: a conductive anode and a conductive cathode; the conductive anode comprises conductive glass, and titanium dioxide, carbon, nitrogen, carbon and quantum dots are loaded on the conductive glass; the conductive cathode comprises a conductive material and a catalyst, wherein the catalyst comprises at least one of carbon black, acetylene black, graphite, graphene, platinum, an iron-based catalyst, a ferro-manganese binary catalyst and a ferro-manganese-copper ternary catalyst.

2. Root of herbaceous plantThe photoelectrocatalytic reactor of claim 1, further comprising a light source having an intensity of 70-95mW/cm²。

3. The photoelectrocatalytic reactor of claim 1, wherein the conductive anode is prepared by a method comprising the steps of:

2) loading the supported TiO₂Carbonizing the conductive glass to obtain TiO₂/C₃N₄An electrode;

3) adding TiO into the mixture₂/C₃N₄And immersing the electrode into a carbon quantum dot solution for treatment to obtain the conductive anode.

4. The photoelectrocatalytic reactor according to claim 1, wherein the mass ratio of the conductive material to the catalyst on the conductive cathode is 1: (0.1-0.8).

5. The photoelectrocatalytic reactor of claim 4, wherein the conductive cathode further comprises a binder.

6. The photoelectrocatalytic reactor according to claim 5, wherein the method of making the conductive cathode comprises the steps of:

and S2, mixing the catalyst and the adhesive, and coating the mixture on the waterproof carbon cloth of S1 to obtain the conductive cathode.

7. Use of a photoelectrocatalytic reactor according to any one of claims 1-6 for the degradation of organic matter.

8. Use of a photoelectrocatalytic reactor according to claim 7, in the degradation of organic matter, wherein said organic matter comprises one or more of carbamazepine, diazepam, triclosan and PPCPs-type contaminants.

9. The application of the photoelectrocatalysis reactor in the degradation of organic matters, which is characterized in that the concentration of the organic matters is 0.5-4 mg/L.

10. Use of a photoelectrocatalytic reactor according to any one of claims 1-6 in the field of power generation.