KR102630344B1 - Perovskite photoelectrode and active-photoelectrochemical reaction system comprising same - Google Patents

Abstract

The present invention relates to a perovskite photoelectric composite electrode and an active solar electrochemical reaction system including the same, and more specifically, to a transparent electrode layer; and a photoelectrocatalyst layer formed on the transparent electrode layer. It includes, wherein the photoelectrocatalyst layer includes: an electrocatalyst layer including oxidized buckypaper (O-BP); and a light absorption layer including an organic-inorganic perovskite layer; It relates to a photoelectric composite electrode and an active solar electrochemical reaction system including the same.

Description

Perovskite photoelectric composite electrode and active solar electrochemical reaction system including the same {PEROVSKITE PHOTOELECTRODE AND ACTIVE-PHOTOELECTROCHEMICAL REACTION SYSTEM COMPRISING SAME}

The present invention relates to a perovskite photoelectric composite electrode and an active solar electrochemical reaction system including the same.

Hydrogen peroxide (H ₂ O ₂ ) is an eco-friendly oxidizing agent that produces only H ₂ O and O ₂ as by-products and is used in wastewater treatment, the paper industry, and pulp bleaching. The energy density of aqueous H ₂ O ₂ (60%; 3.0 MJ L ^-1 ) is the same as that of compressed H ₂ (2.8 MJ L ^-1 at 35 MPa) and is easy to store and transport. Currently, more than 95% of H ₂ O ₂ is produced commercially using the “anthraquinone oxidation” process, but the commercial process consists of complex reaction and separation processes that require significant energy and numerous organic chemicals. Additionally, the noble metal Pd-based catalyst and high pressure H ₂ used during the hydrogenation reaction can increase process costs and cause numerous safety issues.

In this regard, solar H ₂ O ₂ production through single-step reduction of O ₂ using a photocatalyst can provide a simple, safe, and sustainable alternative. It is important to increase the solar-to-chemical conversion efficiency (SCC; %) of compounds (e.g. H ₂ O ₂ ) in sunlight by improving photoelectrode performance and electrocatalyst selectivity. Currently, solar H ₂ O ₂ production applications only use inorganic-based photoelectrodes. These electrodes have inherently untunable band gaps and poor charge transfer properties depending on the band position, resulting in low performance. In connection with H ₂ O ₂ electrocatalysis, porphyrin-based materials containing 3d transition metals have been used due to their high selectivity for H ₂ O ₂ production, but these metals are Because the and N bonds are easily cleaved, it has low stability and is expensive.

In order to solve the above-mentioned problems, the present invention is a perovskite-based device that integrates oxidized buckypaper and can stably produce compounds (e.g., hydrogen peroxide) through an electrochemical reaction using active sunlight. It relates to photoelectric composite electrode.

The present invention includes a perovskite-based photoelectric composite electrode according to the present invention as a photocathode, and is used to produce a compound (e.g., hydrogen peroxide) through an electrochemical reaction using sunlight with unassisted selectivity. , to provide an active solar electrochemical reaction system.

However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to one embodiment of the present invention, a transparent electrode layer; and a photoelectrocatalyst layer formed on the transparent electrode layer. It includes, wherein the photoelectrocatalyst layer includes: an electrocatalyst layer including oxidized buckypaper (O-BP); And a light absorption layer containing an organic-inorganic perovskite; It relates to an opto-electric composite electrode comprising a.

According to one embodiment of the present invention, a protective layer including a fields metal between the electrocatalyst layer and the light absorption layer; It may further include, and the protective layer may be formed on one surface of the electrocatalyst layer.

According to an embodiment of the present invention, the fields metal may have a mass ratio (wt%) of bismuth: indium: tin of 31 to 33:50 to 52:16 to 17.

According to an embodiment of the present invention, the thickness of the electrocatalyst layer and the protective layer may be 1 μm to 3 mm, respectively.

According to an embodiment of the present invention, the thickness of the electrocatalyst layer and the protective layer may be 0.1 mm to 3 mm, respectively.

According to one embodiment of the present invention, the oxidized bucky paper may include CNTs that have been acid-treated at a temperature of 50°C to 100°C in an acid aqueous solution of 50 wt% or more.

According to an embodiment of the present invention, the photoelectric catalyst layer may further include at least one of a hole transport layer, an electron transport layer, and a charge collection layer.

According to one embodiment of the present invention, the hole transport layer is PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)), PANI:PSS (polyaniline:poly(4-styrenesulfonate)) nate), PANI:CSA (polyaniline:cappersulfonic acid), PDBT (poly(4,4'-dimethoxybithiophene), polyhiophenylenevinylene, polyvinylcarbazole, polyparaphenyl It may include at least one selected from the group consisting of poly-p-phenylenevinylene and their derivatives.

According to an embodiment of the present invention, the electron transport layer is fullerene (C60), fullerene (C70), fullerene (C80), PCBM ([6,6]-phenyl-C61 butyric acid methyl ester) (C60), PCBM (C70), PCBM (C80), ThCBM ((6,6)-thienyl-C61-butyric acid methyl ester; ThCBM) and PTCBI (3,4,9,10-perylenetetracarboxylic bisbenzimidazole) It may include

According to one embodiment of the present invention, the charge collection layer is PEI (Poly(ethyleneimine)), PEIE (Poly(ethyleneimine)-ethoxylated,) poly(ethyleneimine)-ethoxylated), and PFN (Poly[(9,9- It contains at least one selected from the group consisting of bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-o-dioctylfluorene)]) You can.

According to an embodiment of the present invention, the hole transport layer may be formed between the light absorption layer and the transparent electrode layer.

According to one embodiment of the present invention, the charge transport layer, the electron collection layer, or both may be formed between the light absorption layer and the protective layer.

According to one embodiment of the present invention, an optical cathode including an opto-electric composite electrode according to the present invention; anode; and membrane; It relates to an active solar electrochemical reaction system including.

According to one embodiment of the present invention, the photoanode includes tungsten (W), molybdenum (Mo), cobalt (Co), manganese (Mn), copper (Cu), iron (Fe), nickel (Ni), and iridium. It may include a photocatalyst for an oxidation reaction containing at least one selected from the group consisting of (Ir) and an oxide thereof.

According to one embodiment of the present invention, the catalyst may be coated on a carbon-based current collector.

According to one embodiment of the present invention, the membrane may be Nafion.

According to an embodiment of the present invention, the photocathode may generate hydrogen peroxide through oxygen reduction, and the photoanode may oxidize water.

According to an embodiment of the present invention, the photocathode may reduce at least one of oxygen, nitrogen, and carbon.

The present invention fuses an existing organic-inorganic mixed perovskite light absorbing material (e.g. MAPbI ₃ ) with an active electrocatalyst (e.g. O-BP, oxidised buckypaper) accompanied by a protective layer (e.g. Fields metal). A photocatalyst-based photoelectric composite electrode that can effectively utilize light energy can be provided.

The present invention provides an active solar electrochemical reaction system by connecting a photocathode and anode (e.g., amorphous iron oxide/nickel composite (a- _NiFeO Conversion efficiency can be improved with compounds (e.g. hydrogen peroxide) and stable system operation can be realized. For example, the present invention can provide a solar hydrogen peroxide generation system capable of actively producing hydrogen peroxide.

1 is a conceptual diagram illustrating the configuration and operation of an active hydrogen peroxide generation system including the photoelectric composite electrode of the present invention, according to an embodiment of the present invention.
Figure 2 shows the analysis and performance of the hydrogen peroxide production catalyst of the photoelectric composite electrode according to an embodiment of the present invention, (a) scanning electron micrograph of O-BP, (b) O-BP A cross-sectional scanning electron micrograph (scale bar, 100 μm), and (c) Raman spectra of BP and O-BP, (d), (e), and (f) XPS (X-ray) of BP and O-BP. This is the result of photoelectron spectroscopy analysis.
Figure 3 shows the analysis and performance of the hydrogen peroxide production catalyst of the photoelectric composite electrode according to an embodiment of the present invention, (a) LSV (Capacitive current compensated linear sweep voltammetry) of BP and O-BP , (b) Faradaic efficiency (FE) of BP and O-BP, and (c) hydrogen peroxide production.
Figure 4 shows (a) a scanning electron microscope image and (b) a cross-sectional scanning electron microscope image of MAPbI ₃ PSK in the catalyst for the photoelectric composite electrode according to an embodiment of the present invention.
Figure 5 shows the performance and analysis of the convergence-type photoelectrocatalyst and the activity of the water oxidation catalyst in the catalyst of the photoelectric composite electrode according to an embodiment of the present invention, (a) JE response of the photocathode and (b) Wavelength-dependent spectral response, (c) JE response of the anode, and (d) temporal potentiometer test results.
Figure 6 is a confirmation of active hydrogen peroxide generation by the system according to the present invention, according to an embodiment of the present invention, and a comparison of the performance of active hydrogen peroxide generation systems reported to date. (a) Comparison of JE responses, (a) b) Comparison of H ₂ O ₂ production (n) and FE (%) and (c) conversion efficiency (solar-to-chemical conversion efficiency, SCC; %) of the compound (H ₂ O ₂ ) in sunlight. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In describing the present invention, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms used in this specification are terms used to appropriately express preferred embodiments of the present invention, and may vary depending on the intention of the user or operator or the customs of the field to which the present invention belongs. Therefore, definitions of these terms should be made based on the content throughout this specification. The same reference numerals in each drawing indicate the same members.

Throughout the specification, when a member is said to be located “on” another member, this includes not only cases where a member is in contact with another member, but also cases where another member exists between the two members.

Throughout the specification, when a part “includes” a certain component, this does not mean excluding other components, but rather means that it can further include other components.

Hereinafter, the photoelectric composite electrode and photoelectrochemical reaction system of the present invention will be described in detail with reference to examples and drawings. However, the present invention is not limited to these examples and drawings.

The present invention relates to a photoelectric composite electrode. According to one embodiment of the present invention, the photoelectric composite electrode actively carries out a photoelectrochemical reaction (e.g., oxidation and/or reduction) by sunlight using a photoelectric catalyst. It can be used to produce environmentally friendly and highly efficient compounds (e.g. hydrogen peroxide).

According to one embodiment of the present invention, the opto-electric composite electrode includes: a transparent electrode layer; And it may include a photoelectric catalyst layer.

According to one embodiment of the present invention, the transparent electrode layer is an electrode with high light transparency through which sunlight passes through, and can be applied without limitation as long as it is applicable to a photoelectrode, for example, ITO, Al on a transparent substrate. -doped ZnO(AZO), Ga-doped ZnO(GZO), In,Ga-doped ZnO(IGZO), Mg-doped ZnO(MZO), Mo-doped ZnO, Al-doped MgO, Ga-doped MgO, F- It may include at least one selected from the group consisting of doped SnO ₂ , Nb-doped TiO ₂ and CuAlO ₂ , but is not limited thereto.

According to one embodiment of the present invention, referring to FIG. 1, the photoelectrocatalyst layer is formed on the transparent electrode layer, includes a light absorption layer and an electrocatalyst layer, and has an organic, inorganic or organic layer between the light absorption layer and the electrocatalyst layer. It may include a hole/electron transfer layer containing these two.

In other words, the present invention proposes a technology that can be driven with high efficiency and high stability by combining a light-absorbing material and an active electrocatalyst, and uses this photoelectric composite electrode system to reduce not only oxygen, but also various reductions such as nitrogen reduction and carbon dioxide reduction. It may be possible to develop photocatalysts and systems for the reaction. In addition, in the present invention, in the case of a high-efficiency organic-inorganic perovskite light-absorbing material, it is very vulnerable to direct contact with water, but the electrocatalyst layer (e.g., Field's metal (FM)) and oxidized bucky paper are each used as a protective layer. and an active layer) and at the same time using a smooth hole/electron transfer layer, it is possible to effectively utilize light energy, show high stability, and efficiently produce compounds (e.g. hydrogen peroxide) through photoelectrochemical reactions.

According to one embodiment of the present invention, the light absorption layer may include a light absorption material layer including an organic-inorganic perovskite. The light-absorbing material is composed of a valence band and a conduction band and may have a band gap due to the difference between two energy levels.

The organic-inorganic perovskite has a longer charge carrier diffusion length, bandgap tunability, and improved optical absorption coefficient, so it can provide many advantages over inorganic-based photoelectrodes.

As an example of the present invention, the organic/inorganic perovskite layer corresponds to a high-efficiency light absorption material and may be an organic/inorganic hybrid perovskite compound represented by the following Chemical Formula 1.

[Formula 1]

A _{a M b}

In Formula 1, A is a monovalent cation, M is a divalent metal cation or a trivalent metal cation, and X and a monovalent anion are. Specifically, A may be a monovalent organic cation, a monovalent inorganic cation, or a combination thereof.

For example, monovalent organic cations include straight or branched C _1-24 alkyl, amine group (-NH ₃ ), hydroxyl group (-OH), cyano group (-CN), halogen group, nitro group (-NO), It may be straight or branched C _{1 to 24} chain alkyl substituted with a methoxy group (-OCH ₃ ) or an imidazolium group, or a combination thereof.

For example, the monovalent inorganic cation may be selected from Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Fr ⁺ , Cu(I) ⁺ , Ag(I) ⁺ and Au(I) ⁺ .

For example, M is Pb ²⁺ , Sn ²⁺ , Ge ²⁺ , Cu ²⁺ , Co ²⁺ , Ni ²⁺ , Ti ²⁺ , Zr ²⁺ , Hf ²⁺ , Rf ²⁺ , In ³⁺ , Bi ³⁺ , Co ³⁺ , Sb ³⁺ and Ni ³⁺ . Specifically, when M is a divalent metal cation, it may be a+2b=c, and when M is a trivalent cation, it may be a+3b=c.

For example, X can be selected from F ^- , Cl ^- , Br ^- and I ^- .

Preferably, the organic-inorganic hybrid perovskite compound is CH ₃ NH ₃ PbInCl _3-n , CH ₃ NH ₃ PbBr _n Cl _3-n , CH ₃ NH ₃ PbInBr _3-n , CH(NH ₂ ) ₂ PbInC _l3-n , CH(NH ₂ ) ₂ PbBr _n Cl _3-n , CH(NH ₂ ) ₂ PbInBr _3-n, MAPbCl ₃ (methylammonium lead chloride), MAPbI _{3 (} methylammonium lead iodide), MAPbBr ₃ (methylammonium lead bromide) ), FAPbI _{3 (} formamidinium lead iodide), MASnCl ₃ (methylammonium tin chloride), MASnBr ₃ (methylammonium tin bromide), MASnI ₃ (methylammonium tin iodide), FASnCl ₃ (formamidinium tin chloride), FASnBr ₃ (formamidinium tin bromide) and It may include at least one selected from the group consisting of FASnI ₃ (formamidinium tin iodide).

According to an embodiment of the present invention, the hole/electron transfer layer is such that when the light absorbing material receives light energy exceeding the band gap, electrons move from the valence band to the conduction band, and the valence band moves into holes (h ⁺ ) and the conduction band. Electrons (e ^- ) are created, and holes (h ⁺ ) and electrons (e ^- ) tend to move to the surface of the material. At this time, in order to effectively move holes and electrons, a hole transport layer (Hole Transfer) is created. It may include at least one of a layer (HTL), an electron transfer layer (ETL), and a charge collector layer.

As an example of the present invention, the hole transport layer includes PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)), PANI:PSS (polyaniline:poly(4-styrenesulfonate), PANI:CSA (polyaniline: cappersulfonic acid), PDBT (poly(4,4'-dimethoxybithiophene), polyhiophenylenevinylene, polyvinylcarbazole, polyparaphenylenevinylene (poly-p-phenylenevinylene) and their derivatives, but is not limited thereto.

As an example of the present invention, the electron transport layer is fullerene (C ₆₀ ), fullerene (C ₇₀ ), fullerene (C ₇₆ ), fullerene (C ₇₈ ), fullerene (C ₈₀ ), fullerene (C ₈₂ ), fullerene (C ₈₄ ), PCBM([6,6]-phenyl-C61 butyric acid methyl ester)(C ₆₀ ), PCBM(C ₇₀ ), PCBM(C ₈₀ ), ThCBM((6,6)-thienyl-C61- It may include at least one selected from the group consisting of fullerene derivatives such as butyric acid methyl ester (ThCBM), PTCBI (3,4,9,10-perylenetetracarboxylic bisbenzimidazole), carbon nanotubes, CdS, CdSe, CdTe, ZnSe, etc. However, it is not limited to this.

As an example of the present invention, the charge collection layer is PEI (Poly(ethyleneimine)), PEIE (Poly(ethyleneimine)-ethoxylated,) poly(ethyleneimine)-ethoxylated), and PFN (Poly[(9,9-bis(3) '-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-o-dioctylfluorene)]), but may include at least one selected from the group consisting of Not limited.

According to an embodiment of the present invention, referring to FIG. 1, the hole transport layer is formed between the organic-inorganic perovskite layer and the transparent electrode layer, and the electron transport layer and the charge collection layer are formed of an organic-inorganic perovskite layer. It is laminated on a skite layer and may be disposed between the electrocatalyst layer and the organic-inorganic perovskite layer.

According to an embodiment of the present invention, the electrocatalyst layer may include a reduction-active electrocatalyst and, for example, may have reduction activity of at least one of oxygen, nitrogen, and carbon. Preferably, it may be oxygen reduction activity. For example, the electrocatalyst layer can generate hydrogen peroxide by reducing oxygen using electrons that move from the light-absorbing material to the surface of the oxygen reduction-active electrocatalyst.

According to one embodiment of the present invention, the electrocatalyst layer may include oxidised buckypaper (O-BP), which provides effective and stable reduction activity by electrons transferred from the light-absorbing material. And, the production efficiency of compounds using sunlight can be improved through photoelectrochemical reactions. For example, it contains a catalyst of the oxidized carbon nanotube (O-CNT) series for effective hydrogen peroxide generation, and catalysts from powder series to sheet series (O-CNT) are used to increase physical stability and adhesion to light-absorbing materials. -BP) can be applied. A composite photoelectrocatalyst can be provided through bonding the oxidized bucky paper and the perovskite material.

According to one embodiment of the present invention, when the electrocatalyst layer has a hydrophilic surface, the surface contact angle with water is 30° or less; Below 25°; Or it may be 10° or less.

As an example of the present invention, the oxidized carbon nanotubes contain 50 wt% or more; Alternatively, it may be acid treated at a temperature of 50°C to 100°C in an aqueous acid solution of 60 wt% or more. The acid aqueous solution may include at least one of nitric acid, sulfuric acid, and hydrochloric acid. This acid treatment induces oxidation of the CNT surface, generating many functional groups with disordered binding sites, which can simultaneously increase the reducing activity (e.g., ORR activity for H ₂ O ₂ ) and selectivity of the oxidized bucky paper. there is.

According to one embodiment of the present invention, the thickness of the electrocatalyst layer is 1 μm or more; 10 μm or more; 50 μm or more; 100 μm or more; 300 μm or more; 10 μm to 200 μm; Or it may be 0.1 mm to 3 mm. If it is within the above range, it can provide a protection function for the light absorption layer and improve the stability and performance of the opto-electric composite electrode.

According to one embodiment of the present invention, a protective layer containing a fields metal may be further included between the electrocatalyst layer and the light absorption layer. The protective layer induces adhesion of the electrocatalyst layer and the light absorption layer and protects the light absorption layer from being damaged by water, etc., thereby increasing the driving stability of the photocathode (e.g., a photoelectrochemical system including a photocathode). , the light absorption layer can efficiently utilize light energy and facilitate electron/hole movement, providing stable work performance over a long period of time.

According to one embodiment of the present invention, the protective layer is formed on one surface of the electrocatalyst layer, and the mass ratio of bismuth (Bi): indium (In): tin (Sn) in the fields metal is 31 to 33:50. to 52:16 to 17. For example, Bi:In:Sn=32.5:51:16.5 (w:w:w).

According to one embodiment of the present invention, the thickness of the protective layer is 1 μm or more; 10 μm or more; 50 μm or more; 100 μm or more; 200 μm or more; 1 μm to 100 μm; Or it may be 0.1 mm to 3 mm. If it is within the above range, the electrocatalyst layer and the light absorption layer can be connected and integrated to form a fusion photoelectrocatalyst, and the stability and performance of the photoelectric composite electrode can be improved by providing a protection function for the light absorption layer.

The present invention relates to a photoelectrochemical reaction system including a photoelectric composite electrode according to the present invention, and according to one embodiment of the present invention, a photocathode including the photoelectric composite electrode according to the present invention; anode; and a membrane.

According to an embodiment of the present invention, the anode may include an electrocatalyst with oxidation activity, for example, an electrocatalyst with water oxidation activity, and oxidation treatment capable of efficiently generating hydrogen peroxide through oxygen reduction. By combining oxidized buckypaper (O-BP) and organic-inorganic mixed perovskite that can efficiently utilize light energy, an active solar electrochemical reaction system (e.g., active hydrogen peroxide generation system) can be provided. You can.

According to one embodiment of the present invention, the anode is tungsten (W), molybdenum (Mo), cobalt (Co), manganese (Mn), copper (Cu), iron (Fe), nickel (Ni), and iridium ( It may include a photocatalyst for an oxidation reaction containing at least one selected from the group consisting of Ir) and at least one of its oxides. _For example _{, it} may be _iridium oxide (IrO No. Preferably, an amorphous iron nickel oxide complex can be applied for effective water oxidation.

As an example of the present invention, the anode may include a catalyst coated on a carbon-based current collector. The carbon-based current collector may be carbon, graphite, carbon nanotubes, activated carbon, etc., but is not limited thereto. The carbon-based current collector is a porous carbon current collector, and the catalyst is loaded on the current collector using ink to ensure wide catalyst distribution.

According to one embodiment of the present invention, the membrane is applicable to a photoelectrochemical reaction system and can be applied without limitation as long as it can compartmentalize them with a membrane function for the operation of the cathode and anode, for example, sulfonic acid It may be a perfluorosulfonic acid-based ion exchange membrane with a group (-SO ₃ H), and more specifically, it may be a Nafion membrane, Gore membrane, Flemion membrane, or Aciplex membrane. Preferably, it may be a Nafion film. For example, the reaction at the anode and the reaction at the cathode can induce redox reactions in independent spaces through a Nafion separator.

According to one embodiment of the present invention, the photoelectrochemical reaction system may further include additional components for operation and obtaining desired products, for example, a supply pipe for supplying oxygen to the photocathode for generation of hydrogen peroxide. It may further include.

According to an embodiment of the present invention, the photoelectrochemical reaction system may provide reduction activity of at least one of oxygen, nitrogen, and carbon in the photocathode. For example, hydrogen peroxide can be generated through the oxygen reduction activity. That is, referring to Figure 1, oxidized buckypaper (O-BP), which can efficiently generate hydrogen peroxide through oxygen reduction, and organic-inorganic mixed perovskite that can efficiently utilize light energy. It is an active hydrogen peroxide generation system that includes a photocathode fused with , and the anode region in the opposite region can balance oxidation and reduction charges by oxidizing water in the amorphous iron oxide/nickel complex (a-NiFeO _x ). The oxidation/reduction charge is balanced by oxidizing water in the amorphous iron/nickel oxide complex (a- _NiFeO Holes that move to the surface can oxidize water and generate oxygen.

According to one embodiment of the present invention, the photoelectrochemical reaction system is 0.740 μmol min ^-1 cm ^-2 or more; 0.750 μmol min ^-1 cm ^-2 or more; or H ₂ O ₂ production rate of more than 0.751 μmol min ^-1 cm ^-2 and more than 1.45%; 1.46% or more; It can provide an SCC of 1.463% or more.

Although the present invention is described with reference to preferred embodiments, the present invention is not limited thereto, and is to be understood without departing from the spirit and scope of the present invention as set forth in the following claims, the detailed description of the invention, and the accompanying drawings. The present invention can be modified and changed in various ways.

Example

Preparation of oxidized CNTs (O-CNTs)

Multi-walled CNTs (MWCNTs) were oxidized by acid treatment according to a commonly known method. MWCNTs (400 mg) and nitric acid (60 wt%, 400 mL) were added to a 500 mL three-neck round bottom glass flask. Next, the flask was equipped with a magnetic stirrer and thermometer and placed on a temperature controller in the reflux system. After maintaining the temperature at 80 °C for 48 h, the slurry was cooled to room temperature (~25 °C), poured, filtered, and washed several times with distilled water until neutral pH was reached. Finally, the samples were dried in a vacuum oven at 60 °C overnight.

Carbon material sheet preparation

Carbon powder (50 mg) and 150 mL of DMF (150 mL, Sigma-Aldrich, anhydrous, 99%) were placed in a 250 mL chemical storage bottle, tip sonicated at 25% amplitude for 15 minutes, and then dispersed by bath ultrasonication for 2 hours. I ordered it. The dispersion was filtered through a polytetrafluoroethylene membrane (0.45 μm pore size) and washed three times with acetone (600 mL). Next, the as-formed carbon sheet was carefully peeled off from the membrane and dried in a vacuum oven at 60 °C overnight.

Catalytic electrode preparation

To prepare the electrode, a carbon sheet (approximately 1.0 × 0.7 cm ² ) was cut and placed on FM-covered glass, interfaced with insulating copper wire and silver conductive paint, and covered with epoxy resin to form a geometrical area of 0.25 cm ² .

Fabrication of perovskite photocathode

The PbI ₂ (Sigma-Aldrich, approximately 1 M, >99% purity) precursor was prepared by dissolving PbI ₂ powder (exactly 462 mg) in 9:1 (v:v) DMF and DMSO (Sigma Aldrich, anhydrous, 99%). Manufactured. A PCBM solution (20 mg mL ^-1 ) dissolved in chlorobenzene (Sigma-Aldrich, anhydrous, 99%) was maintained at 70°C overnight with constant stirring, and the MAI (10 mg mL ^-1 ; a great solar cell) was 2. -Dissolved in propanol (Sigma Aldrich, anhydrous, 99%). The inverse structure of the mixed halide perovskite film was fabricated using a previously reported two-step spin coating method. That is, PEDOT:PSS was spin-coated on a 1 × 1.5 cm ² FTO glass substrate at 4,000 rpm for 60 seconds and annealed at 120 °C for 20 minutes to form HTL.

Relative humidity was maintained at ~20%. The sample was then immediately transferred to a glove box filled with N ₂ . Samples were each preheated to 146 ± 4 °C on a hot plate for approximately 5 min, dispensed with 150 μL of hot PbI ₂ ink (150 μL), and spin-coated at 2,200 rpm for 20 s with an acceleration of 440 rpm s ^-1 ; Next, it was placed in an airtight Petri dish for 7 minutes. Next, the film was annealed at 70 °C for 15 minutes and then cooled to glove box temperature (approximately 27-29 °C). The dark brown MAPbI ₃ film was activated by dispensing MAI (0.063 M, 350 μL) at 0 rpm for 40 s and 2,700 rpm for 20 s to wash away the remaining propanol from the FTO. After spin coating, the film was annealed at 85 °C for 10 minutes. Then, PCBM-chlorobenzene solution (80 μL) was deposited at 2,000 rpm for 30 seconds to obtain the completed structure. For better electron extraction by the catalyst, a thin layer of PEIE solution (0.1 mL in 5 mL of 2-propanol) was spin-coated at 3,000 rpm for 30 s. To protect the perovskite from deterioration, an FM sheet (1.0 × 0.7 cm ² ) was melted on the perovskite layer at a temperature below ≤ 70 °C and dried by storing it in a glove box overnight.

Perovskite device integration

To prepare the photocathode, O-BP sheets (approximately 1.0 × 0.7 cm ² ) were precisely bonded to the molten FM/PSK photocathode and epoxy coated to provide a geometric area of 0.25 cm ² on the back of the electrocatalyst and FTO substrates. covered simultaneously with resin. Finally, the insulated copper wire was connected to the FTO board to complete device manufacturing.

a -NiFeO _x /CP anode

The a-NiFeOx/CP anode was composed of iron (III) ethylhexanoate (0.0358 g, 50% w/w in mineral spirits, Strem Chemicals) and nickel (II) ethylhexanoate ( II) ethylhexanoate (0.0169 g, 78 % (w/w) in 2-ethylhexanoic acid, Strem Chemicals) was placed in a vial and mixed with hexane (0.1520 g). Next, a portion (0.1 mL) of the formed solution was diluted with hexane (dilution 1:10). Next, a portion of the precursor solution (exactly 2.5 μL) was drop-cast directly onto the CP (0.25 cm ² ). After drying in air for 5 minutes, the electrode was annealed in an oven at 100°C for 1 hour. Finally, the exposed wire area was encapsulated with JB Weld epoxy-steel resin and the copper wire was connected to the anode to secure an area of 0.25 cm ² .

Electrochemical measurements

Electrochemical measurements were performed in a standard three-electrode system with cathode and anode separated by a Nafion 117 membrane (DuPont). Nafion proton exchange membrane was selected to concentrate HO ₂ ^- anions, and Pt mesh (1 × 1 cm ² ), Hg/HgO, and carbon sheet were used as counter electrode, reference electrode, and working electrode, respectively. In this experiment, all potentials were measured relative to the Hg/HgO electrode and converted to the RHE reference scale by the equation E (V vs. RHE) = E (V vs. Hg/HgO) + 0.0592 × pH + 0.118. Before testing, the Nafion 117 membrane was soaked with distilled water for ~2 hours to sufficiently swell. Before electrolysis, the electrolyte was purged with high purity O ₂ (99.995%) for at least 10 minutes to remove residual air in the reaction system. During electrolysis, high purity O ₂ (99.995 %) was fed continuously (at a rate of 50 cc min ^-1 ) to the cathode compartment with magnetic stirring. For comparison, electrolysis tests were also performed in high purity Ar (99.999%) saturated electrolyte under the same experimental conditions. All current densities were normalized to the geometric area of the electrode.

PEC measurement

Photoelectrochemical measurements to determine activity (particularly JV curve) were performed in a standard three-electrode system using a half-cell reactor. Pt mesh (1 × 1 cm ² ), Hg/HgO (1 M NaOH), and O-BP/FM/PSK photocathode were used as counter, reference, and working electrodes, respectively.

All potentials in this experiment were measured relative to the Hg/HgO reference electrode and converted to the RHE reference scale by the equation E (V vs. RHE) = E (V vs. Hg/HgO) + 0.0592 × pH + 0.118. PEC measurements to confirm performance (especially to visualize long-term stability) were performed in a standard two-electrode system in a two-compartment reactor. A two-compartment reactor containing 0.1 M KOH solution (7.5 mL) in both the amod chamber and the cathode chamber was separated by a Nafion 117 membrane and activated by maintaining it in deionized water for 2 hours before reaction. a -NiFeO _x /CP anode and O-BP/FM/PSK photocathode were used as counter electrode and working electrode, respectively.

Before photoelectrolysis, the electrolyte was purged with high purity O ₂ (99.995%) for at least 30 minutes (flow rate 50 cc min ^-1 ) to remove residual air in the reaction system. Additionally, mass transfer limitations were overcome by continuously supplying high-purity O ₂ with magnetic stirring from near the electrocatalyst surface to the cathode compartment during photoelectrolysis. For comparison, electrolysis experiments were also performed in high purity (99.999%) Ar-saturated electrolyte under the same experimental conditions. All current densities were normalized to the geometric area of the photoelectrode, and the scan rate was maintained at 5 mV s ^-1 during measurements. A 300 W xenon lamp was used to generate simulated 1-sun radiation with a water filter. A silicon reference cell (certified by Newport Corporation; PEC-SI01, Peccell Technologies) was placed parallel to the beam light of the xenon lamp to adjust the light intensity to 1-sun on the FTO side (backside illumination).

PEC H ₂ O ₂ Detection and Quantification

The H ₂ O ₂ concentration was determined by collecting aliquots of the desired volume from the catholyte at regular intervals and storing them in the refrigerator before measurement. Using the commonly used N,N -diethyl-1,4-phenylene-diamine sulfate (DPD, N , N -diethyl-1,4-phenylene-diamine sulphate)-peroxidase (POD) method Concentration was determined at 551 nm. That is, DPD (50 mg, ≥98.0%, Sigma-Aldrich) and POD (5 mg, horseradish, Sigma-Aldrich) were dissolved in 0.1 NH ₂ SO ₄ (5 mL) and deionized water (5 mL), respectively, and stored at 5 °C. It was stored in a dark room. Finally, 0.1 M sodium phosphate buffer (2.7 mL, ~pH 6.0), a portion of DPD (0.05 mL) and POD (0.05 mL) solutions, and catholyte (0.2 mL) were mixed. Depending on the concentration of H ₂ O ₂ produced, the sample was diluted with 0.1 M KOH to ensure that it did not exceed the detection limit. For quantification, a standard calibration curve was plotted against concentration and absorbance (Supplementary Fig. 29a,b), and the value of the resulting concentrated H ₂ O ₂ was determined as a function of time. IPCE measurements were performed using a 300 W xenon lamp as the light source and a monochromator with a bandwidth limit of 20 nm. The intensity of the reference light was calibrated before IPCE measurements.

Development of oxygen reduction electrocatalyst and active hydrogen peroxide generation system using it

Figure 1 shows a conceptual diagram of an active hydrogen peroxide production system using an oxidized buckypaper-perovskite fusion photoelectrocatalyst, according to an embodiment of the present invention.

a _{-NiFeO _} -iron oxide) is connected for bias-free H ₂ O ₂ production. The embedded copper wire connects the photocathode and anode to allow photogenerated hole-electron pairs to flow in a closed circuit. Dissolved O ₂ is reduced to H ₂ O ₂ by photocathode-equipped O-BP. The oxygen evolution reaction (OER) occurs in a -NiFeO _x /CP. The red arrow indicates the direction of electron movement, and the blue arrow indicates the direction of simultaneously generated holes. In Figure 1, they are PCBM ([6,6]-phenyl C ₆₁ butyric acid methyl ester), PEIE (polyethyleneimine), and FTO (fluorine-doped tin oxide).

Figure 2 shows the analysis and performance of the hydrogen peroxide production catalyst.

(a) This is a scanning electron micrograph of O-BP, and the inset photo shows O-BP removed from the polytetrafluoroethylene membrane (scale bar, 1 μm). (b) This is a cross-sectional scanning electron micrograph of O-BP (Scale bar, 100 μm). In other words, a large surface area can be secured through the porosity of the sheet-based catalyst (Figures 2 (a) and (b)).

(c) Raman spectra of BP and O-BP.

(d) XPS (X-ray photoelectron spectroscopy) analysis results of BP and O-BP. Deconvoluted carbon 1 s spectra of BP(e) and O-BP(f).

In other words, active sites that are more advantageous for oxygen reduction than general CNTs can be identified (Figure 2 (c), (d), (e), and (f)).

Figure 3 shows the analysis and performance of the hydrogen peroxide production catalyst.

Figure 3 (a) is the LSV (capacitive current compensated linear sweep voltammetry) of BP and O-BP evaluated at a scan rate of 10 mV s ^-1 .

(b) (c) Quantity produced (n) and Faradaic efficiency (FE) of BP and O-BP during 12 h of controlled potential electrolysis (CPE), where error bars represent standard deviation.

(ac) -0.6 V vs. Long-term CPE testing of O-BP in RHE, all experiments were performed in 0.1 M KOH solution (pH ca. 13.17) with stirring in O ₂ and ambient conditions. In other words, it is possible to secure oxygen reduction ability superior to that of general CNTs (Figure 3 (a), (b), and (c)).

In Figure 2 (a), O-CNTs were synthesized by acid treating CNTs in nitric acid (60 wt%) at 80°C for 48 hours. Buckypaper (BP) and O-BP are synthesized by filtration of CNTs and O-CNTs, respectively, and scanning electron micrographs (SEM) and images (inset) of BP and O-BP are randomly self-aligned and closely linked to each other. CNTs and O-CNTs are shown.

As shown in Figure 2(b), BP and O-BP are densely packed but have high surface areas with many mesopores. Raman and X-ray photoelectron spectroscopy (XPS) analyzes were performed to investigate the chemical structure. The Raman spectrum ((c) in FIG. 2) has a D (about 1350 cm ^-1 )-to-G (about 1580 cm ^-1 ) peak ratio of 1.08 and 1.14 for BP and O-BP, respectively. Acidic treatment of CNTs caused structural disorder, creating many defects in O-CNTs, and XPS analysis was also performed to further investigate the detailed surface structure (Figures 2(d) to (f)).

Figure 2(d) indicates that CNTs are oxidized during acid treatment, as the oxygen to carbon ratio increases for O-BP compared to BP samples. Carbon materials due to desorption of functional groups of functionalized carbon materials (O-BP and O-CNT) in thermogravimetric analysis (TGA) analysis; Their weight loss occurs when the temperature increases to 500 °C. The carbon 1s spectra of BP (and O-BP) are 284.6 eV (and 284.7 eV), 285.5 eV (and 285.4 eV), 286.4 eV (and 286.7 eV), and 289.1 eV (and 289.1 eV), respectively; The characteristic shakeup line of carbon is identified at 291.1 eV (and 291.1 eV, Figure 2 (e) and Figure 2 (f)), where the shakeup line is the excitation of the ground level electron (π-π* transition) ) occurs due to the immediate energy loss of photoelectrons emitted.

These XPS results show that O-BP undergoes a two-electron oxygen reduction reaction (ORR, two-electron It shows that it has more defect sites than BP, including structural disorders such as sp3 carbon, which is known to be a highly active H ₂ O ₂ generation site for oxygen reduction reaction, and functional groups such as O-adhering carbon. Additionally, due to the increase in O-adhering carbon, O-CNTs are more dispersible in deionized water and N,N-dimethylformamide (DMF), indicating that O-BP has a more intimate interaction with water than BP. The contact angles of O-BP and BP are 25° and 134°, respectively, indicating that O-CNT is more hydrophilic than CNT. O-CNTs also exhibit a more negative zeta potential in 0.1 M KOH aqueous solution than CNTs, leading to easier product separation (O ₂ + H ₂ O + 2e ^- →HO ₂ ^- + OH ^- ) and improved H ₂ O ₂ indicates the formation of (HO ₂ ^- in alkaline solution).

Capacitive compensated linear sweep voltammetry (LSV) curves of BP and O-BP in aqueous solution (0.1 M KOH, pH approximately 13.17) under continuous O ₂ flow (50 cc min ^-1) to evaluate the ORR performance of BP and O-BP. was obtained (Figure 3(a)). O-BP shows a higher onset potential and higher current density than BP. The onset potential of O-BP is higher than the standard reduction potential ((E° = 0.74 V vs. RHE; possible initially by the Nernst equation).

Here, the onset potential is defined as the potential at 0.1 mA cm ^-2 . Moreover, the selectivity of O-BP for H ₂ O ₂ production is close to 100%, which is higher than that observed for BP at potentials above 0.6 V (Figure 3(b)).

In particular, O-BP generates a higher absolute amount of H ₂ O ₂ than BP at all applied potentials (FIG. 3(b)). As described above, acid treatment can induce oxidation of the CNT surface to generate many functional groups with disordered defect sites, thereby improving both the activity and selectivity of ORR for H ₂ O ₂ . Current density and FE are 0.6 V vs. It is stable for 12 hours with 100% selectivity in RHE, where O-BP shows the highest selectivity and H ₂ O ₂ amount (Figure 3(c)).

Figures 4 and 5 show the performance and analysis of the fusion photo-electrocatalyst and the activity of the water oxidation catalyst, and are related to the characterization and ORR activity of the O-BP fusion PSK photocathode.

Figure 4(a) and (b) are scanning electron micrographs of the surface and cross-section of the formed MAPbI ₃ PSK showing the thickness of the individual layers. That is, the surface and cross-sectional structure of the light-absorbing material can be confirmed (Figures 4 (a) and (b)).

Figure 5(a) shows the JE response of the O-BP electrocatalyst, Fields Metal (FM)/PSK photocathode, and composite O-BP/FM/PSK photocathode device showing anodic shift. . A composite O-BP/FM/PSK photocathode device was simulated under 1-sun and an air mass of 1.5 G, and average cyclic voltammogram (Avg. CV) scans were performed in the absence of light with O ₂ supply and without light irradiation. (red arrow indicates the scan direction during the experiment).

In other words, when oxygen is reduced using a fusion photo-electrocatalyst, an initiation voltage of about 1 V is secured, showing an oxygen reduction initiation voltage of 1.77 V (Figure 5(a)).

Figure 5(b) shows the wavelength-dependent spectral response (i.e., IPCE (incident-photon-to-current efficiency)) and 0 V vs. is the corresponding integrated photocurrent density of the fused device in RHE. In other words, using organic and inorganic perovskite, it shows excellent photocurrent conversion efficiency even in the visible light range.

Figure 5 (c) is the JE reaction of a -NiFeO _x /CP anode without stirring, and the inset shows the exact overpotential for OER.

Figure 5 (d) is the result of a chronopotentiometry test of a -NiFeO _x /CP anode performed in a three-electrode setting.

In (a-d) of Figure 5, the experiment was performed under ambient conditions with a scan rate of 5 mV s ^-1 in 0.1 M KOH solution (pH about 13.17), and all scale bars are equal to 1 μm. That is, in the case of the water oxidation catalyst, high stability can be confirmed at an initiation voltage of 1.52 V (Figures 5 (c) and (d)).

Figure 6 compares the performance of confirmed and reported active hydrogen peroxide generation systems, according to one embodiment of the present invention. It can be confirmed through the starting voltage that active hydrogen peroxide generation is possible by connecting a fusion photo-electrocatalyst and a water oxidation catalyst. Active hydrogen peroxide generation is confirmed and the performance of the reported active hydrogen peroxide generation system is compared.

Figure 6 (a) shows that the operating point obtained from the overlap of the integrated system of a -NiFeO _x /CP anode and O-BP/FM/PSK photocathode for the generated solar H ₂ O ₂ is Provides a photocurrent of ~2.51 mA cm ^-2 for the production of solar H ₂ O ₂ .

Figure 6 (b) shows that the unassisted H ₂ O ₂ production (n) of the fusion O-BP/FM/PSK device in the two-electrode setup under simulated 1-sun conditions is approximately without degradation at 0 V for 12 days. 442 ± 15.2 μmol cm ^-2 of H ₂ O ₂ can be continuously generated. Error bars represent standard deviation based on average data from five fusion devices _representing nH2O2 and FE (%). In other words, it was experimentally proven that active hydrogen peroxide production is possible by connecting a fusion photo-electric catalyst and a water oxidation catalyst (FIG. 6 (a) and (b)).

In Figure 6 (c), a graph showing the production rate of solar H ₂ O ₂ on the left y-axis, and the conversion efficiency (Solar to chemical efficiency, SCC); %) from the corresponding solar light to chemical substances on the right y-axis. displayed. The highest SCC efficiency peaks after 2 hours of reaction. In other words, the active hydrogen peroxide generation system developed through this study shows the highest fuel conversion efficiency among systems developed to date (Figure 6(c)).

The present invention provides an oxidized-bucky paper (O-BP), which, when combined with Field's Metal (FM) to prevent water ingress, acts as a protective layer and a selective electrocatalyst for H ₂ O ₂ production. , oxidised buckypaper) was used to successfully passivate high-performance inorganic-organic perovskite (PSK) photoelectrodes. The H ₂ O ₂ production selectivity of the O-BP electrocatalyst was close to 100% (Faradaic efficiency, FE = 100%), and it showed excellent stability for 100 hours by periodically supplying new electrolyte to the reaction system. Additionally, we demonstrated unassisted solar H ₂ O ₂ production using a two-electrode system consisting of an O-BP/FM/PSK photocathode and an a-NiFeOx anode, which is the highest value reported for a photoelectrode system to date. It represents an SCC of approximately 1.463%. Additionally, this system is stable for 45 hours under 1-sun illumination with 100% H ₂ O ₂ production selectivity. By optimizing PSK, ETL, HTL and electrocatalyst components, the SCC (%) and stability of the overall system can be further improved. Additionally, this passivation strategy can be applied to various reactions, such as CO ₂ and N ₂ reduction, by simply changing the electrocatalyst of the PSK photoelectrode. Accordingly, the present invention may provide a strategy for efficiently producing other valuable solar chemicals for carbon-based fuel applications and NH ₃ .

The present invention is a highly efficient inorganic-organic perovskite that is passivated by selective and stable oxidized buckypaper (O-BP) and Field's Metal (FM) as an electrocatalyst for H ₂ O ₂ production. A photocathode based on perovskite (PSK) (e.g. MAPbI ₃ ) can be provided.

In the present invention, inorganic-organic perovskite (PSK) can be efficiently protected by FM coupled O-BP electrocatalyst. O-BP can be produced by filtering oxidised carbon nanotubes (O-CNT), which are known efficient H ₂ O ₂ electrocatalysts, and the cross-linked O-CNT structure of O-BP provides selective and efficient electricity. It can act as a catalyst. FM (melts at approximately 65 °C and solidifies at room temperature) is used to securely adhere the PSK film to the O-BP, but can also facilitate charge transfer between them and provide a protective layer for the PSK film against moisture penetration. You can. This composite system shows stability over long periods of time compared to the non-passivated PSK layer, which loses its activity within a few minutes. Additionally, a H ₂ O ₂ production rate of approximately 0.751 μmol min ^-1 cm ^-2 and an SCC of approximately 1.463% were achieved, which are among the highest values for solar H ₂ O ₂ production via a photoelectrocatalytic system reported to date. It applies.

As described above, although the embodiments have been described with limited examples and drawings, various modifications and variations can be made by those skilled in the art from the above description. For example, even if the described techniques are performed in a different order than the described method, and/or the described components are combined or combined in a different form than the described method, or are replaced or substituted by other components or equivalents. Adequate results can be achieved. Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the claims described below.

Claims (16)

Transparent electrode layer; and
A photoelectric catalyst layer formed on the transparent electrode layer;
Including,
The photoelectrocatalyst layer is,
An electrocatalyst layer containing oxidized buckypaper (O-BP); and
A light absorption layer including an organic-inorganic perovskite layer;
which includes,
Optoelectric composite electrode.
According to paragraph 1,
a protective layer containing fields metal between the electrocatalyst layer and the light absorption layer;
It further includes,
The protective layer is formed on one side of the electrocatalyst layer,
Optoelectric composite electrode.
According to paragraph 2,
The mass ratio (w/w) of bismuth: indium: tin among the Fields metals is,
31 to 33:50 to 52:16 to 17,
Optoelectric composite electrode.
According to paragraph 1,
The oxidized bucky paper is,
Comprising CNTs acid-treated at a temperature of 50 ° C to 100 ° C in an aqueous acid solution of 50 wt% or more,
Optoelectric composite electrode.
According to paragraph 1,
The photoelectrocatalyst layer is,
At least one of a hole transport layer, an electron transport layer, and a charge collection layer
which further includes,
Optoelectric composite electrode.
According to clause 5,
The hole transport layer is,
PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)), PANI:PSS (polyaniline:poly(4-styrenesulfonate), PANI:CSA (polyaniline:cappersulfonic acid), PDBT (poly(4,4'-dimethoxybithiophene), polythiophenylenevinylene, polyvinylcarbazole, poly-p-phenylenevinylene and their derivatives Containing at least one selected from the group consisting of,
Optoelectric composite electrode.
According to clause 5,
The electron transport layer is,
Fullerene (C60), fullerene (C70), fullerene (C80), PCBM ([6,6]-phenyl-C61 butyric acid methyl ester) (C60), PCBM (C70), PCBM (C80), ThCBM ((6, 6) -thienyl-C61-butyric acid methyl ester; ThCBM) and PTCBI (3,4,9,10-perylenetetracarboxylic bisbenzimidazole),
Optoelectric composite electrode.
According to clause 5,
The charge collection layer is,
PEI (Poly(ethyleneimine)), PEIE (Poly(ethyleneimine)-ethoxylated) and PFN (Poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt -2,7-(9,9-o-dioctylfluorene)]), which contains at least one selected from the group consisting of
Optoelectric composite electrode.
According to clause 5,
The hole transport layer is,
Formed between the light absorption layer and the transparent electrode layer,
Optoelectric composite electrode.
delete An optical cathode comprising the photoelectric composite electrode of claim 1;
anode; and
membrane;
Including,
Active solar electrochemical reaction system.
According to clause 11,
The anode is,
At least one selected from the group consisting of tungsten (W), molybdenum (Mo), cobalt (Co), manganese (Mn), copper (Cu), iron (Fe), nickel (Ni), and iridium (Ir) and an oxide thereof Containing a photocatalyst for an oxidation reaction containing at least one selected from the group consisting of,
Active solar electrochemical reaction system.
According to clause 12,
The photocatalyst is,
Coated on a carbon-based current collector,
Active solar electrochemical reaction system.
According to clause 11,
The membrane is,
Nafion,
Active solar electrochemical reaction system.
According to clause 11,
The optical cathode is,
Reducing at least one of oxygen, nitrogen and carbon,
Active solar electrochemical reaction system.
According to clause 11,
The photocathode generates hydrogen peroxide by oxygen reduction,
The anode oxidizes water,
Active solar electrochemical reaction system.