CN109187705B - a photoelectrochemical cell - Google Patents

Abstract

The invention provides a photoelectrochemical cell, comprising a photocathode and a photoanode, the photocathode and the photoanode are arranged in parallel in space, and the projection of the photocathode and the photoanode in a direction perpendicular to the plane where the photocathode and the photoanode are located do not overlap each other. The photocathode and the photoanode of the photoelectrochemical cell provided by the present invention can simultaneously receive vertical sunlight irradiation to the greatest extent. The two poles of the photoelectrochemical cell designed with this structure can be prepared by techniques such as coating method and printing, and the process is simple and has the advantages of It has a patterning function, is easy for industrial continuous production, can receive light at the same time, does not need to use a proton membrane, can be made into a flexible device, and has a high utilization rate of sunlight. The photoelectrochemical cell provided by the invention can degrade organic pollutants at the photoanode, remove various heavy metal ions at the photocathode, and carry out hydrogen production reaction, so as to achieve the dual purposes of solar decontamination, removal of heavy metal ions, and solar hydrogen production, thereby solving environmental problems. Pollution and energy crisis issues.

Description

a photoelectrochemical cell

technical field

The invention belongs to the technical field of photoelectrochemistry, and particularly relates to a photoelectrochemical cell and a preparation method thereof.

Background technique

Photoelectrochemical cells, which absorb solar energy through photoelectrodes and convert light energy into electricity. Generally, semiconductors are used as photoelectrodes, n-type semiconductors are used as photoanode, and p-type semiconductors are used as photocathode. Photogenerated electron-hole pairs are generated; after the electron-hole pairs are separated, due to the upward bending of the electrode surface energy band and the drive of the photo-generated voltage, the electrons move to the bulk phase, and pass through the external circuit under the photo-generated bias voltage or external bias voltage. When reaching the counter electrode, the electrons reach the counter electrode to participate in the reduction reaction, while the holes migrate to the surface of the photoanode to participate in the oxidation reaction. During this whole process, a loop is formed and an electric current is generated. In 1972, Fujishima and Honda first reported a photoelectrochemical cell composed of semiconductor _TiO2 as the photoanode and Pt as the photocathode, and hydrogen was produced on the Pt photocathode. In 1976, Carey discovered that the semiconductor _TiO2 photoanode can degrade various organic pollutants under ultraviolet light irradiation. Therefore, in a photoelectrochemical cell, the role of the photoelectrode is to absorb light energy, convert the light energy into holes or electrons that can participate in chemical reactions, and undergo oxidation reactions and degrade organic substances at the photoanode, and reduction reactions and heavy metals occur at the photocathode. The ions are reduced to produce hydrogen, while solving the problems of environmental pollution and energy crisis. In addition, in order to effectively prevent the recombination of photogenerated electron-hole pairs and improve the degradation rate of organic matter, the deposition rate of heavy metal ions, and the production rate of hydrogen, it is often necessary to apply a certain bias voltage to the photoelectrode to pass the photoelectrons through the external The circuit is driven to the counter electrode to achieve efficient separation of electron-hole pairs, thereby achieving an organic combination of waste degradation and clean energy production.

At present, the photoelectrochemical cell usually adopts a single-chamber or double-chamber structure, often requires the use of a proton exchange membrane, and the photoanode and photocathode are on two sides, which need to be prepared separately, the process is complicated, and the utilization efficiency of sunlight is low.

SUMMARY OF THE INVENTION

In view of this, the technical problem to be solved by the present invention is to provide a photoelectrochemical cell. The photoelectrochemical cell provided by the present invention has a simple preparation method, has a patterning function, is easy for industrialized continuous production, and can receive light at the same time without using a proton membrane. , the utilization rate of sunlight is high.

The invention provides a photoelectrochemical cell, comprising a photocathode and a photoanode, the photocathode and the photoanode are arranged in parallel in space, and the projection of the photocathode and the photoanode in a direction perpendicular to the plane where the photocathode and the photoanode are located do not overlap each other.

Preferably, one of the photocathode and the photoanode is a ring-shaped planar electrode or formed by connecting a plurality of ring-shaped planar electrodes in series, and the other electrode is arranged at any arbitrary position in the projection on the vertical direction of the inner ring of the ring-shaped planar electrode. One or more electrodes of any shape in position and shape are connected in series;

or,

The photocathode and the photoanode are arranged in isolation.

Preferably, the annular plane is selected from a regular triangle ring, a square ring or a regular hexagonal ring, the pole piece formed by connecting a plurality of annular planes in series is a secondary shape obtained by combining several annular planes, and the two The stage shape is selected from triangles, trapezoids, parallelograms, squares, rectangles, crosses or honeycombs.

Preferably, the shape of the single electrode of the other pole is consistent with the shape of the inner ring of the annular planar electrode, and the area of the single electrode of the other pole is smaller than or equal to the inner ring area of the annular planar electrode.

Preferably, at least one of the photoanode and the photocathode is a photocatalytic electrode. Preferably, the photoanode is a photocatalytic electrode or both the photoanode and the photocathode are photocatalytic electrodes.

Preferably, the photoanode includes a photoanode conductive substrate and an n-type semiconductor layer compounded on the surface of the photoanode conductive substrate, and the photocathode includes a photocathode conductive substrate and a p-type semiconductor layer compounded on the surface of the photocathode conductive substrate Semiconductor layer, the thickness of the pole piece of the photoanode is 0.1 μm to 50 cm, the thickness of the n-type semiconductor layer is 0.1 μm to 50 cm, and the thickness of the pole piece of the photocathode is 0.1 μm to 50 cm, and the thickness of the p-type semiconductor layer is 0.1 μm to 50 cm. The thickness of 0.1μm ~ 50cm.

Preferably, the preparation method of the photoanode is:

Coating or printing the paste containing n-type semiconductor on the surface of the photoanode conductive substrate, and drying to obtain the photoanode, the n-type semiconductor is selected from TiO ₂ , V ₂ O ₅ , WO ₃ , Hematite, CuWO ₄ , BiVO ₄ , SnNb ₂ O ₆ , S ₂ TiO ₄ , α-SnWO ₄ , LaTiO ₂ N, Ta ₃ N ₅ , BaTaO ₂ N, ZnO, FeS ₂ , one or more of CdS, CdSe, CdTe, ZnS and GaP , the photoanode conductive substrate is selected from one or more of ITO conductive substrates, FTO conductive substrates, titanium, platinum, stainless steel, aluminum, copper, and carbon materials;

The preparation method of the photocathode is:

The slurry containing p-type semiconductor is coated or printed on the surface of the photocathode conductive substrate, and after drying, a photocathode is obtained, the p-type semiconductor is selected from TiSi ₂ , and the photocathode conductive substrate is selected from ITO conductive substrate, FTO One or more of conductive substrates, titanium, platinum, stainless steel, aluminum, copper, and carbon materials.

Preferably, the coating method is selected from slit coating or blade coating; the printing method is selected from inkjet printing, spray coating, gravure printing, letterpress printing, screen printing, transfer printing, stroke method and 3D printing one or more of.

Preferably, it also includes a light-transmitting casing, an electrolyte disposed in the casing, and an electrochemical workstation for providing an applied voltage, wherein the photocathode and the photoanode are disposed in the electrolyte, and are in contact with the electrolyte. The flow directions are parallel, and the casing is provided with an electrolyte inlet, an electrolyte outlet and a gas outlet, and the gas outlet is connected with a gas recovery device.

Preferably, the electrolyte is selected from organic waste water containing organic pollutants, and the organic waste water containing organic pollutants is selected from urban domestic sewage, food processing and paper industry waste water, and one or more of oil and gas field waste water. ;

The transparent shell is selected from one or more of glass, quartz glass and plexiglass, and the material of the plexiglass is selected from PE, PET, PP, PI, PC, PMMA, PS, EVA, PBS, One or more of PA.

Compared with the prior art, the present invention provides a photoelectrochemical cell, comprising a photocathode and a photoanode, wherein the photocathode and the photoanode are arranged in parallel in space, and the photocathode and the photoanode are in parallel with the photocathode and the photoanode. The projections in the vertical direction of the plane do not overlap each other. The photocathode and the photoanode of the photoelectrochemical cell provided by the present invention can simultaneously receive vertical sunlight irradiation to the greatest extent, and the two poles of the photoelectrochemical cell designed with this structure can be prepared by techniques such as coating method and printing technology, and the process is simple, It has the function of patterning, is easy for industrialized continuous production, can receive light at the same time, does not need to use a proton membrane, can be made into a flexible device, and has a high utilization rate of sunlight. The photoelectrochemical cell provided by the invention can degrade organic pollutants at the photoanode, remove various heavy metal ions at the photocathode, and carry out hydrogen production reaction, so as to achieve the dual purposes of solar decontamination, removal of heavy metal ions, and solar hydrogen production, thereby solving environmental problems. Pollution and energy crisis issues.

Description of drawings

1 is a schematic structural diagram of a single electrode of an annular planar electrode provided by the present invention;

2 is a schematic diagram of an electrode structure with a parallelogram in the secondary shape obtained by combining six equilateral triangle rings;

3 is a schematic diagram of an electrode structure with a rectangular secondary shape obtained by combining six square rings;

4 is a schematic diagram of the electrode structure with a honeycomb-shaped secondary shape obtained by combining seven regular hexagonal rings;

5 is a schematic diagram of the shape and structure of the other pole of the two electrodes;

Fig. 6 is the top view after the photocathode and photoanode of three different structures are combined respectively;

Fig. 7 is the structural representation of the photoelectrochemical cell provided by the present invention;

8 is a schematic structural diagram of the photocathode and the photoanode provided in Example 1 being compounded on the surface of one side inside the light-transmitting glass casing;

9 is a schematic disassembly diagram of the structure of the photocathode and the photoanode compound provided in Example 2 on the surface of one side inside the light-transmitting glass casing;

10 is a schematic structural diagram of the composite structure of the photocathode and the photoanode provided in Example 2, which are composited on the surface of one side inside the light-transmitting glass shell;

Fig. 11 is the curve of the current density of the photoelectrochemical cell under simulated sunlight and 1V voltage with time;

Fig. 12 is the change curve of the removal rate of organic pollutant-phenanthrene with electrolysis time.

Detailed ways

The invention provides a photoelectrochemical cell, comprising a photocathode and a photoanode, the photocathode and the photoanode are arranged in parallel in space, and the projection of the photocathode and the photoanode in a direction perpendicular to the plane where the photocathode and the photoanode are located do not overlap each other.

In some specific embodiments of the present invention, one of the photocathode and the photoanode is a ring-shaped planar electrode or formed by connecting a plurality of ring-shaped planar electrodes in series, and the other electrode is arranged perpendicular to the inner ring of the ring-shaped planar electrode. One or more electrodes of any position and shape in the projection on the direction are connected in series. Wherein, at least one of the two electrodes is a photocatalytic electrode, in some embodiments of the present invention, the photoanode is a photocatalytic electrode; in other embodiments of the present invention, both the photoanode and the photocathode are photocatalytic electrodes .

Wherein, the present invention does not limit the shape of the annular plane of the annular plane electrode. Preferably, the shape of the outer ring of the annular plane is consistent with the shape of the inner ring; further preferably, the center of the outer ring and the inner ring coincide. Further preferably, the shape of the annular plane is an equilateral triangle ring, a square ring or a regular hexagonal ring. Referring to FIG. 1, FIG. 1 is a schematic structural diagram of a single electrode of the annular plane electrode provided by the present invention. A square ring electrode, a regular hexagonal ring electrode and a regular triangle ring electrode, the pole piece formed by a plurality of annular planes in series is a secondary shape obtained by combining a plurality of annular planes, and the secondary shape is selected from the group consisting of triangle, Trapezoid, parallelogram, square, rectangle, cross or honeycomb.

Wherein, when the secondary shape is a triangle, the secondary shape may be obtained by combining several equilateral triangle rings;

When the secondary shape is a trapezoid, the secondary shape can be obtained by combining several equilateral triangle rings;

When the secondary shape is a parallelogram, the secondary shape can be obtained by combining several equilateral triangle rings; referring to Fig. 2, Fig. 2 shows that the secondary shape obtained by combining six equilateral triangle rings is a parallelogram. Schematic diagram of the electrode structure.

When the secondary shape is a square, the secondary shape can be obtained by combining several square rings;

When the secondary shape is a rectangle, the secondary shape may be obtained by combining several square rings; refer to FIG. 3 , which is a schematic diagram of an electrode structure with a rectangular secondary shape obtained by combining six square rings.

When the secondary shape is a cross, the secondary shape can be obtained by combining several square rings;

When the secondary shape is a regular hexagon, the secondary shape can be obtained by combining several regular hexagonal rings; referring to FIG. 4 , the secondary shape obtained by combining seven regular hexagonal rings is: Schematic diagram of the honeycomb electrode structure.

In some specific embodiments of the present invention, the shape of the single electrode of the other pole of the two electrodes is consistent with the shape of the inner ring of the annular planar electrode and its shape covers the entire plane, and the single electrode of the other pole The area of the electrode is less than or equal to the area of the inner ring of the annular planar electrode. The shape of the other pole of the two electrodes is shown in FIG. 5 . FIG. 5 is a schematic diagram of the shape and structure of the other pole of the two electrodes. In Fig. 5, from left to right, the square, the regular hexagon and the regular triangle cover the entire plane respectively.

After the photocathode and the photoanode are combined, an electrode of the photoelectrochemical cell is formed. Referring to FIG. 6 , FIG. 6 is a top view of the combination of the photocathode and the photoanode with three different structures.

In other specific embodiments of the present invention, the photocathode and the photoanode are arranged in isolation, that is, one pole of the photocathode and the photoanode is arranged on the side of the other pole. Preferably, the single electrodes of the photocathode and the photoanode have the same shape and structure, and the single photocathodes are arranged in an array and connected in series to form a photocathode, and the individual photoanodes are arranged in an array and connected in series to form a photoanode.

The photoanode includes a photoanode conductive substrate and an n-type semiconductor layer compounded on the surface of the photoanode conductive substrate, the photocathode includes a photocathode conductive substrate and a p-type semiconductor layer compounded on the surface of the photocathode conductive substrate, The thickness of the pole piece of the photoanode is 0.1 μm˜50 cm, preferably 1 μm˜10 cm. The thickness of the n-type semiconductor layer is 0.1 μm to 50 cm, preferably 1 μm to 10 cm, the thickness of the pole piece of the photocathode is 0.1 μm to 50 cm, and the thickness of the p-type semiconductor layer is 0.1 μm to 50 cm.

In the present invention, the above technical solutions are only preferred technical solutions, and the shapes and structures of the photocathode and photoanode are not limited to the above solutions, as long as they can ensure that the photocathode and photoanode can be simultaneously and receive vertical sunlight to the greatest extent. Electrolytic structures and shapes are within the scope of the present invention.

In the present invention, the preparation method of the photoanode is:

Coating or printing the paste containing n-type semiconductor on the surface of the photoanode conductive substrate, and drying to obtain the photoanode, the n-type semiconductor is selected from TiO ₂ , V ₂ O ₅ , WO ₃ , Hematite, CuWO ₄ , BiVO ₄ , SnNb ₂ O ₆ , S ₂ TiO ₄ , α-SnWO ₄ , LaTiO ₂ N, Ta ₃ N ₅ , BaTaO ₂ N, ZnO, FeS ₂ , one or more of CdS, CdSe, CdTe, ZnS and GaP , preferably TiO ₂ , and the photoanode conductive substrate is selected from one or more of ITO conductive substrates, FTO conductive substrates, titanium, platinum, stainless steel, aluminum, copper, and carbon materials;

The preparation method of the paste containing the n-type semiconductor is:

The n-type semiconductor is dispersed in a solvent containing a binder to obtain a slurry, and the solvent is selected from chloroform, NMP, dichloromethane, toluene, ethanol, isopropanol, ethylene glycol, distilled water, DMF, and ether. One or more of them, preferably chloroform-ethylene glycol-ethanol mixed solvent. The binder is selected from one or more of PVA, PVDF, PMMA, PS and PTFE, preferably PVA.

The preparation method of the photocathode is:

The slurry containing p-type semiconductor is coated or printed on the surface of the photocathode conductive substrate, and after drying, a photocathode is obtained, the p-type semiconductor is selected from TiSi ₂ , and the photocathode conductive substrate is selected from ITO conductive substrate, FTO One or more of conductive substrates, titanium, platinum, stainless steel, aluminum, copper, and carbon materials.

The preparation method of the paste containing p-type semiconductor is:

The p-type semiconductor is dispersed in a solvent containing a binder to obtain a slurry, and the solvent is selected from chloroform, NMP, dichloromethane, toluene, ethanol, isopropanol, ethylene glycol, distilled water, DMF, and ether. One or more of them, preferably chloroform-ethylene glycol-ethanol mixed solvent. The binder is selected from one or more of PVA, PVDF, PMMA, PS and PTFE, preferably PVA.

In the preparation of photocathode and photoanode, the coating method is selected from slit coating or blade coating; the printing method is selected from inkjet printing, spraying, gravure printing, letterpress printing, screen printing, transfer printing, One or more of stroke method and 3D printing.

The photoelectrochemical cell provided by the present invention further comprises a light-transmitting casing, an electrolyte disposed in the casing, and an electrochemical workstation for providing an applied voltage, wherein the photocathode and the photoanode are disposed in the electrolyte, and are connected with the electrolyte. The flow direction of the electrolyte is parallel, and the casing is provided with an electrolyte inlet, an electrolyte outlet and a gas outlet, and the gas outlet is connected with a gas recovery device.

In some specific embodiments of the present invention, the photocathode and the photoanode are in the same plane, and the conductive substrates of the photocathode and the photoanode are combined on one side of the inside of the light-transmitting housing.

Preferably, the electrolyte is selected from organic waste water containing organic pollutants, and the organic waste water containing organic pollutants is selected from urban domestic sewage, food processing and paper industry waste water, and one or more of oil and gas field waste water. ;

The transparent shell is selected from one or more of glass, quartz glass and plexiglass, and the material of the plexiglass is selected from PE, PET, PP, PI, PC, PMMA, PS, EVA, PBS, One or more of PA.

The structure of the photoelectrochemical cell provided by the present invention will be described in detail below with reference to the accompanying drawings. Referring to FIG. 7, FIG. 7 is a schematic structural diagram of the photoelectrochemical cell provided by the present invention.

The photoelectrochemical cell provided in FIG. 7 includes a closed light-transmitting casing, and an electrolyte inlet (sewage inlet), an electrolyte outlet (sewage outlet) and a gas outlet are provided on the shell of the light-transmitting casing, and the gas outlet is connected to There is a gas recovery device. In addition, the inside of the light-transmitting casing is filled with an electrolyte, the photocathode and the photoanode are arranged inside the light-transmitting casing, and are immersed in the electrolyte, and the positive electrode and the negative electrode are connected to the electricity supplying the applied voltage through the wire respectively. ChemStation is connected.

The working principle of the photoelectrochemical cell provided by the present invention is:

The function of the photoelectrode is to absorb light energy and convert the light energy into holes or electrons that can participate in chemical reactions. The oxidation reaction occurs at the anode, and the organic matter is oxidized and degraded; the reduction reaction occurs at the cathode, and the heavy metal ions are reduced. A variety of heavy metals such as Ni, Cu, Pb, Fe, Ca, Mg, Na, etc. are deposited on it, and hydrogen can also be generated.

The photocathode and the photoanode of the photoelectrochemical cell provided by the present invention can simultaneously receive vertical sunlight irradiation to the greatest extent, and the two poles of the photoelectrochemical cell designed with this structure can be prepared by techniques such as coating method and printing technology, and the process is simple, It has the function of patterning, is easy for industrialized continuous production, can receive light at the same time, does not need to use a proton membrane, can be made into a flexible device, and has a high utilization rate of sunlight. The photoelectrochemical cell provided by the invention can degrade organic pollutants at the photoanode, remove various heavy metal ions at the photocathode, and carry out hydrogen production reaction, so as to achieve the dual purposes of solar decontamination, removal of heavy metal ions, and solar hydrogen production, thereby solving environmental problems. Pollution and energy crisis issues.

In order to further understand the present invention, the photoelectrochemical cell provided by the present invention is described below with reference to the examples, and the protection scope of the present invention is not limited by the following examples.

Example 1

1. The patterning of the conductive substrate: a conductive substrate layer (material is titanium Ti) with a desired pattern is prepared on the surface of one side inside the light-transmitting glass shell, wherein the photocathode and the photoanode are isolated and arranged, The shape, size and number are the same, and the shape is a rectangle, the length of the rectangle is 20cm, the width is 10cm, the thickness is 50μm, and the number is 1.

2. Printing preparation of photoelectrode layer:

Disperse 0.5g of photoanode catalyst _TiO2 in 5ml of chloroform-ethylene glycol-ethanol (volume ratio 5:3:2) mixed solvent containing PVA binder (0.05g), grind for 1h, and prepare The paste is printed on the surface of the conductive substrate by screen printing technology. The drying temperature of the solvent in the paste is below 350°C, and after drying, an n-type semiconductor layer with a thickness of 10 μm is obtained;

Disperse 0.5 g of photoanode catalyst TiS ₂ in 5 ml of chloroform-ethylene glycol-ethanol (volume ratio 5:3:2) mixed solvent containing PVP binder (0.05 g), grind for 1 h, and prepare The paste is printed on the surface of the conductive substrate by screen printing technology, and the drying temperature of the solvent in the paste is below 350° C. After drying, a p-type semiconductor layer with a thickness of 10 μm is obtained.

The photocathode and the photoanode are respectively connected by wires.

Referring to FIG. 8 , FIG. 8 is a schematic structural diagram of the photocathode and the photoanode provided in Example 1 being compounded on the surface of one side inside the light-transmitting glass casing.

Example 2

1. The patterning method of the conductive substrate is the same as that in Example 1

2. Printing preparation of photoelectrode layer:

Preparation of _TiO photoanode by combining 500 mg WO (purchased from Sigma _– Aldrich, ≤20 μm, ≥99% purity), 0.5 mL anhydrous ethylene glycol and 50 μL polyethylene glycol octyl phenyl ether (Triton X-100) A uniform _TiO2 photoanode slurry was prepared; 400 μL of the uniform slurry was applied to the conductive substrate (1.5cm X 1.5cm X 1.5cm) on which Ti had been deposited, dried at 60 °C overnight, and finally heated at 200 °C for 30 min to The remaining ethylene glycol was removed to obtain a photoanode with an n-type semiconductor layer having a thickness of 10 μm.

Preparation of TiSi photocathode, 500 _mg TiSi (purchased from Sigma _– Aldrich), 0.5 mL anhydrous ethylene glycol, and 50 μL polyethylene glycol octyl phenyl ether (Triton X-100) _were prepared into a uniform TiSi photocathode Slurry; take 400 μL of this homogeneous slurry and apply it to a conductive substrate (1.5cm X 1.5cm X 1.5cm) on which Ti has been deposited by screen printing technology, dry at 60°C overnight, and finally heat at 200°C for 30min to remove the remaining ethylene glycol to obtain a photocathode with a p-type semiconductor layer having a thickness of 10 μm.

Example 3

1. Patterning of the conductive substrate: deposit a layer of conductive substrate with the desired pattern on the surface of one side inside the light-transmitting glass shell, and the material is carbon fiber.

2. Printing preparation of photoelectrode layer:

Disperse 0.5g of photoanode catalyst _TiO2 in 5ml of chloroform-ethylene glycol-ethanol (volume ratio of 5:3:2) mixed solvent containing PVP binder (0.05g), and grind for 1h to prepare The paste is printed on the surface of a conductive substrate with a thickness of 50 μm by screen printing technology, and the drying temperature of the solvent in the paste is below 350 ° C, and the n-type semiconductor layer with a thickness of 10 μm is obtained after drying;

Disperse 0.5 g of photoanode catalyst TiS ₂ in 5 ml of chloroform-ethylene glycol-ethanol (volume ratio 5:3:2) mixed solvent containing PVP binder (0.05 g), grind for 1 h, and prepare The paste is printed on the surface of a conductive substrate with a thickness of 50 μm by screen printing technology, and the drying temperature of the solvent in the paste is below 350° C. After drying, a p-type semiconductor layer with a thickness of 10 μm is obtained.

The photocathode and the photoanode are respectively connected by wires.

Wherein, the photoanode is a rectangular photoanode formed by combining and connecting the single electrodes of six square rings in series, wherein the six square rings are combined to form two rows, and the sides of adjacent square rings are arranged adjacent to each other. The side length of the outer ring of the square ring is 2 cm, the side length of the inner ring is 1.5 cm, and the centers of the inner ring and the outer ring are coincident.

The photocathode is six square sheets with the same size, and the side length is 2cm. The six square sheets with the same size are respectively nested inside the six square rings of the photoanode, and the center of the photocathode is connected to the photoanode. the center coincides.

Referring to FIG. 9 and FIG. 10, FIG. 9 is a schematic disassembly diagram of the structure of the photocathode and the photoanode provided in Example 2 being compounded on the surface of one side inside the light-transmitting glass casing, and FIG. 10 is the photocathode and the photoanode provided in Example 2. A schematic diagram of the composite structure after the anode is composited on the surface of one side inside the light-transmitting glass shell.

Example 4

1. The patterning method of the conductive substrate is the same as that in Example 2

2. Printing preparation of photoelectrode layer:

Preparation of _TiO photoanode by combining 500 mg WO (purchased from Sigma _– Aldrich, ≤20 μm, ≥99% purity), 0.5 mL anhydrous ethylene glycol and 50 μL polyethylene glycol octyl phenyl ether (Triton X-100) A uniform _TiO2 photoanode slurry was prepared; 400 μL of the uniform slurry was applied to the conductive substrate (1.5cm X 1.5cm X 1.5cm) on which Ti had been deposited, dried at 60 °C overnight, and finally heated at 200 °C for 30 min to The remaining ethylene glycol was removed to obtain a photoanode with an n-type semiconductor layer having a thickness of 10 μm.

Preparation of TiSi photocathode, 500 _mg TiSi (purchased from Sigma _– Aldrich), 0.5 mL anhydrous ethylene glycol, and 50 μL polyethylene glycol octyl phenyl ether (Triton X-100) _were prepared into a uniform TiSi photocathode Slurry; take 400 μL of this homogeneous slurry and apply it to a conductive substrate (1.5cm X 1.5cm X 1.5cm) on which Ti has been deposited by screen printing technology, dry at 60°C overnight, and finally heat at 200°C for 30min to remove the remaining ethylene glycol to obtain a photocathode with a p-type semiconductor layer having a thickness of 10 μm.

The photocathode and the photoanode are respectively connected by wires.

Wherein, the photoanode is a rectangular photoanode formed by combining and connecting the single electrodes of six square rings in series, wherein the six square rings are combined to form two rows, and the sides of adjacent square rings are arranged adjacent to each other. The side length of the outer ring of the square ring is 2 cm, the side length of the inner ring is 1.5 cm, and the centers of the inner ring and the outer ring are coincident.

The photocathode is six square sheets with the same size, and the side length is 2cm. The six square sheets with the same size are respectively nested inside the six square rings of the photoanode, and the center of the photocathode is connected to the photoanode. the center coincides.

Example 5

According to the schematic structural diagram of the photoelectrochemical cell provided in FIG. 7 of the specification of the present invention, the photocathode and the photoanode prepared in Examples 1 to 4 are assembled into the photoelectrochemical cell, and the photoelectrochemical cells I to IV are obtained respectively, wherein the composition of the electrolyte used is See Table 1, which is the composition of the electrolyte of the photoelectrochemical cell.

The composition of the electrolyte of table 1 photoelectrochemical cell

Example 6

The photoelectrochemical cell V having the structure shown in the photoelectrochemical cell II is made by the method of Example 5. The photoanode is the same as the preparation of the photoanode in Example 2. The difference from the photoelectrochemical cell II is the photocathode. Pt is plated on the conductive substrate to form a Pt cathode (size 1.5cm X 1.5cm X 1.5cm), and finally a photoelectrochemical cell V is made.

Example 7

Performance test of photoelectrochemical cells II and V: Chronoamperometry was used to measure the current density versus time curve of the two cells under simulated sunlight and a voltage of 1V. The results are shown in Figure 11. Figure 11 shows the photoelectrochemical cells in simulated sunlight And the change curve of its current density with time at 1V voltage. The instrument used was a multi-channel potentiostat; UV spectrophotometry was used to determine the change curve of the content of organic pollutants-phenanthrene with electrolysis time. The results are shown in Table 2 and Figure 12, and Figure 12 is the removal rate of organic pollutants-phenanthrene. Variation curve with electrolysis time. From the results, it can be seen that both photoelectrochemical cells II and V can be used to degrade organic pollutants. The difference between photoelectrochemical cells II and V is that both electrodes of II are photocatalytic electrodes, while the V cell is a photoanode and a non-photocathode; the current of photoelectrochemical cell II in Figure 11 is higher than that of photoelectrochemical cell V, resulting in a photoelectric The phenanthrene removal rate of organic pollutants in chemical cell II was higher than that of photoelectrochemical cell V, as shown in Figure 12. The results show that when both electrodes are photocatalytic electrodes, the utilization efficiency of sunlight is higher and the degradation effect of organic matter is better.

Table 2 Comparison of removal rates of phenanthrene in two photoelectrochemical cells under different electrolysis times

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as It is the protection scope of the present invention.

Claims (10)

1. A photoelectrochemical cell comprising a photocathode and a photoanode, wherein the photocathode and the photoanode are spatially arranged in parallel, and projections of the photocathode and the photoanode in a direction perpendicular to a plane in which the photocathode and the photoanode are located do not overlap with each other;

one of the photocathode and the photoanode is an annular plane electrode or is formed by connecting a plurality of annular plane electrodes in series, and the other one of the photocathode and the photoanode is formed by connecting one or a plurality of electrodes which are arranged at any position in the projection in the vertical direction of the inner ring of the annular plane electrode and have any shape in series.

2. The photoelectrochemical cell of claim 1, wherein the annular plane is selected from a regular triangular ring, a square ring, or a regular hexagonal ring, and the pole piece formed by connecting a plurality of annular planes in series is a secondary shape obtained by combining a plurality of annular planes, and the secondary shape is selected from a triangular shape, a trapezoidal shape, a parallelogram shape, a cross shape, or a honeycomb shape.

3. The photoelectrochemical cell of claim 1, wherein the shape of the individual electrode of the other pole conforms to the shape of the inner annulus of the annular planar electrode, and the area of the individual electrode of the other pole is less than or equal to the area of the inner annulus of the annular planar electrode.

4. The photoelectrochemical cell of claim 1, wherein at least one of the photoanode and the photocathode is a photocatalytic electrode.

5. The photoelectrochemical cell of claim 1, wherein the photo-anode is a photocatalytic electrode or both the photo-anode and the photo-cathode are photocatalytic electrodes.

6. The photoelectrochemical cell according to claim 1, wherein the photoanode comprises a photoanode conductive substrate and an n-type semiconductor layer compounded on the surface of the photoanode conductive substrate, the photocathode comprises a photocathode conductive substrate and a p-type semiconductor layer compounded on the surface of the photocathode conductive substrate, the thickness of a pole piece of the photoanode is 0.1 μm to 50cm, the thickness of the n-type semiconductor layer is 0.1 μm to 50cm, the thickness of a pole piece of the photocathode is 0.1 μm to 50cm, and the thickness of the p-type semiconductor layer is 0.1 μm to 50 cm.

7. The photoelectrochemical cell of claim 1, wherein the photoanode is prepared by a method comprising:

coating or printing the slurry containing the n-type semiconductor on the surface of the conductive substrate of the photo-anode, and drying to obtain the photo-anode, wherein the n-type semiconductor is selected from TiO₂，V₂O₅，WO₃，Hematite, CuWO₄, BiVO₄, SnNb₂O₆, S₂TiO₄, α-SnWO₄, LaTiO₂N, Ta₃N₅, BaTaO₂N, ZnO，FeS₂The photo-anode conductive substrate is selected from one or more of an ITO conductive substrate, an FTO conductive substrate, titanium, platinum, stainless steel metal, aluminum, copper and carbon material;

the preparation method of the photocathode comprises the following steps:

coating or printing the slurry containing the p-type semiconductor on the surface of a photocathode conductive substrate, and drying to obtain the photocathode, wherein the p-type semiconductor is selected from TiSi₂The photocathode conductive substrate is selected from one or more of an ITO conductive substrate, an FTO conductive substrate, titanium, platinum, stainless steel metal, aluminum, copper and a carbon material.

8. The photoelectrochemical cell of claim 7, wherein the coating is performed by a method selected from the group consisting of slot coating or knife coating; the printing method is selected from one or more of ink-jet printing, spray coating, gravure printing, letterpress printing, screen printing, transfer printing, pen drawing and 3D printing.

9. The photoelectrochemical cell of claim 1, further comprising a light permeable housing, an electrolyte disposed within the housing, and an electrochemical station for providing an applied voltage, wherein the photocathode and the photoanode are disposed within the electrolyte in a direction parallel to a flow direction of the electrolyte, wherein the housing is provided with an electrolyte inlet and an electrolyte outlet and a gas outlet, and wherein the gas outlet is connected to a gas recovery device.

10. The photoelectrochemical cell of claim 9, wherein the electrolyte is selected from organic wastewater containing organic contaminants selected from one or more of municipal sewage, wastewater from food processing and paper industry, wastewater from oil and gas fields;

the light-permeable shell is selected from one or more of glass, quartz glass and organic glass, and the material of the organic glass is selected from one or more of PE, PET, PP, PI, PC, PMMA, PS, EVA, PBS and PA.

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