44results about "Hydrogen peroxide" patented technology

The utility model discloses a gasified hydrogen peroxide supply device which comprises an evaporator, a hydrogen peroxide supply pipeline, a sterile air supply pipeline for atomization and a sterile hot air supply pipeline for gasification. The hydrogen peroxide supply pipeline and the sterile air supply pipeline for atomization are connected with the mist input end of the evaporator, the sterile hot air supply pipeline for gasification is connected with the hot air input end of the evaporator, and the gasified hydrogen peroxide supply device further comprises a descaling pipeline. The hydrogen peroxide evaporation path is covered with the descaling agent conveying path, it is guaranteed that the descaling agent makes contact with all dirt, the dirt is removed along the original gasified hydrogen peroxide generation path, the heat conduction efficiency of the evaporator is maintained, and the gasification quality of the whole gasified hydrogen peroxide supply device is guaranteed.

Decomposition apparatus for hydrogen peroxide, comprising at least one reaction chamber which, when used as intended, contains an immobilized catalyst, characterized in that the catalyst used can be separated from the reaction mixture by decantation.

The application provides high-crystalline carbon nitride, a preparation method thereof and application thereof in photocatalytic production of hydrogen peroxide. The preparation method of the high-crystalline carbon nitride comprises the following steps: S1: calcining melamine under a nitrogen atmosphere, and cooling, washing and drying after calcination to obtain bulk-phase carbon nitride; and S2: uniformly mixing potassium chloride, lithium chloride and the bulk-phase carbon nitride, and then calcining under a nitrogen atmosphere, and cooling, washing and drying after calcination to obtain high-crystalline carbon nitride. The high-crystalline carbon nitride has high crystallinity, a large surface area and more active sites, and has excellent photocatalytic performance, which is conducive to efficient photocatalytic production of hydrogen peroxide.

To provide a discharge device capable of discharging highly concentrated ejection product material.SOLUTION: A discharge device 1 ejects ejection product material into the air. The discharge device 1 comprises: a housing 11; a discharge electrode 131; and two protection portions 141 and 141. The discharge electrode 131 projects from the housing 11. The discharge electrode 131 ejects the ejection product material into the air by performing a discharge. Each protection portion 141 is one portion and the housing 11 is another portion. The two protection portions 141 and 141 are provided with the discharge electrode 131 interposed between the two protection portions. Each protection portion 141 includes: a pair of supporting portions 161 and 161; and an electrode protection portion 151. The pair of supporting portions 161 and 161 is provided in the housing. Each supporting portion 161 extends toward a direction separated from the housing 11. A terminal end portion of each supporting portion 161 is arranged at a position more separated from the housing 11 than a distal end portion 13A of the discharge electrode 131. The electrode protection portion 151 connects the terminal end side of one support portion 161 to the other support portion 161.SELECTED DRAWING: Figure 4

The invention relates to a composition comprising: an aqueous solution of hydrogen peroxide; one or more organic carbonates selected from dialkyl carbonates and alkylene carbonates or one or more lactones; and one or more organic acids selected from monocarboxylic acids comprising at least 10 carbon atoms and polycarboxylic acids. The invention also relates to the use of this composition for recycling a material comprising a polyepoxy matrix, as well as to a recycling process for such a material using this composition.

The present application relates to a kind of preparation of ion liquid modified carbon nitride composite and photosynthesis hydrogen peroxide.The present application provides a new type of ion liquid doped carbon nitride photocatalytic synthesis hydrogen peroxide, to solve the existing carbon nitride material photocatalytic synthesis hydrogen peroxide production low and the problem of not high visible light utilization rate.Method: one, the preparation of carbon nitride raw material;Two, the preparation of ion liquid doped carbon nitride sample.The preparation process of the present application is simple and effective, reagent consumption is less and the yield is high;And the photocatalyst provided by the present application can effectively improve the photosynthesis hydrogen peroxide efficiency.The present application is applied to the field of photocatalytic synthesis hydrogen peroxide, and experiment shows that the material has excellent photocatalytic synthesis hydrogen peroxide performance, and the synthesis hydrogen peroxide rate can reach 657 μmol·g ‑1 ·h ‑1 under visible light irradiation.

The invention discloses a transition metal oxyhydroxide modified BiOCl photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of photocatalytic materials. According to the photocatalyst, a BiOCl nano-plate serves as a carrier, transition metal oxyhydroxide MOOH is loaded on the surface of the BiOCl nano-plate, M is at least one of Co, Fe, Mn and Ni, and the mass ratio of MOOH to BiOCl ranges from 1: 20 to 1: 5. The preparation method comprises the following steps: synthesizing a BiOCl nano-plate through a hydrothermal method, dispersing the BiOCl nano-plate in a solution containing sulfate radicals and transition metal ions, and growing MOOH on the surface of BiOCl in situ through a photo-induced deposition method under an alkaline condition. Through surface modification of MOOH, separation and migration of BiOCl photon-generated carriers are effectively promoted, attack of photo-generated holes to Cl in BiOCl crystal lattices is inhibited, photo-corrosion of BiOCl is remarkably reduced, and the structural stability and photocatalytic activity of BiOCl are improved. The catalyst shows excellent performance in the aspects of degradation of organic pollutants (such as glyphosate wastewater) and photocatalytic generation of H2O2, and has the advantages of low cost, simple process and easiness in large-scale production.

The invention discloses a donor-receptor type carbon nitride photocatalyst as well as a preparation method and application thereof, and the preparation method of the donor-receptor type carbon nitride photocatalyst comprises the following steps: mixing a carbon nitride precursor with molten salt, and calcining to obtain cyano-modified carbon nitride; and mixing the cyano-modified carbon nitride with 4, 4 '-diphenyldicarboxylic acid, and calcining to realize a covalent bonding reaction, thereby obtaining the donor-receptor type carbon nitride photocatalyst. According to the carbon nitride photocatalyst, an asymmetric donor-acceptor structure is constructed, a strong built-in electric field is induced, meanwhile, cyano serves as a proton / electron repository, the charge separation efficiency and the proton transmission capacity are remarkably improved, and therefore photocatalytic preparation of hydrogen peroxide is efficiently achieved.

This invention discloses a method for preparing hydrogen peroxide using ultra-low temperature photocatalysis. The method includes: adding a photocatalytic material to water or a solution and dispersing it completely, adjusting the pH to obtain a reaction solution; adding O2 to the reaction solution until saturation, and turning on a light source to initiate the photocatalytic reaction; after the reaction, detecting the concentration of H2O2 using potassium iodide-ammonium molybdate spectrophotometry; the photocatalytic material is a semiconductor metal oxide; and the temperature of the photocatalytic reaction is -5 to -60°C. This method significantly increases the reactant concentration by concentrating the catalyst and oxygen in micron-sized intercrystalline water at ultra-low temperatures. Furthermore, the ultra-low temperature allows for rapid desorption of the catalytically generated hydrogen peroxide, inhibiting its decomposition reaction, thereby significantly improving the production of hydrogen peroxide per unit mass and per unit time.

The invention relates to the field of porous materials, in particular to a method for loading metal nanoparticles on a functionalized metal organic framework and catalytic application. The conventional method for loading metal nanoparticles on a metal organic framework carrier is faced with the problem of serious agglomeration caused by high surface energy of atoms, so that the formed particles are large and non-uniform in size, the pore channels of the metal organic framework are blocked, the number of active sites is reduced, and the catalytic performance is seriously influenced. In order to solve the problems, different functionalization regulators are anchored at metal nodes of the metal organic framework, the nucleation and growth processes of metal nanoparticles are regulated and controlled by utilizing the unique coordination effect of the functionalization regulators, the dispersity of the metal nanoparticles is effectively improved, the size of the metal nanoparticles is controllably regulated, and the metal organic framework material is endowed with excellent performance in the aspect of photocatalysis.

The invention discloses a photocatalytic material with a heptazine-triazine structure as well as a preparation method and application of the photocatalytic material. Relates to the field of photocatalysis. The photocatalytic material with the heptazine-triazine structure comprises a boron-doped heptazine-triazine heterojunction structure, and the content of a triazine unit in the heptazine-triazine heterojunction structure is higher than that of a heptazine unit; the raw material of the boron-doped heptazine-triazine heterojunction structure comprises the following components: a boron-containing carbon nitride precursor and alkali metal salt, the raw materials of the boron-containing carbon nitride precursor comprise melamine and a boron source. The photocatalytic material shows excellent performance under visible light, the H2O2 yield can reach 2423 mol L <-1 > h <-1 > (44.1 times of that of traditional carbon nitride), and the hydrogen evolution rate is increased by 70 times; the apparent quantum yield of 450nm single wavelength reaches 14.4%, and the visible light absorption range is effectively expanded; and after continuous 24-hour illumination, the activity is not attenuated, and the stability is excellent.

The invention relates to the technical field of inorganic and organic nano composite materials, and discloses preparation and application of a sulfur vacancy regulated Zn0. 5Cd0. 5S / MIL-68 (In)-NH2 composite material, firstly, MIL-68 (In)-NH2 microrods are synthesized, then the MIL-68 (In)-NH2 microrods are dispersed in deionized water, Zn (NO3) 2.6 H2O, Cd (NO3) 2.4 H2O and thioacetamide are sequentially added, sulfur vacancy is introduced through hydrazine hydrate, the sulfur vacancy regulated Zn0. 5Cd0. 5S / MIL-68 (In)-NH2 composite material is obtained, and the sulfur vacancy regulated Zn0. 5Cd0. 5S / MIL-68 (In)-NH2 composite material is prepared. The catalyst is used for converting light energy into chemical energy under sunlight to realize preparation of chemical energy H2O2 and treatment of MBT wastewater. The prepared composite material has good light absorption performance and light energy conversion activity.

The application discloses anthraquinone-based polysulfate and a preparation method and photocatalytic application thereof, and belongs to the field of polymer material synthesis and photocatalytic technology. The polysulfate takes 2,6-dihydroxyanthraquinone derivative as a core monomer, is connected through a sulfate bond to form a conjugated polymer, and has excellent visible light absorption capacity and electron transport performance. The preparation method takes 2,6-dihydroxyanthraquinone as a starting material, synthesizes a double silyl ether protected anthraquinone intermediate and a thiofluoride activated anthraquinone intermediate respectively, and finally performs polycondensation on the two intermediates under a potassium hydrogen fluoride / crown ether catalytic system. The material can catalyze hydrogen peroxide to be generated from water and oxygen under visible light irradiation, and the yield reaches 2667 μmol·h ‑1 ·g ‑1 , is a new type of efficient photocatalytic material, and has wide application prospects in the fields of green synthesis and environmental catalysis.

The application discloses a method for in-situ growth of perovskite quantum dots on carbon nitride nanosheets, and products and applications thereof. Perovskite quantum dot precursors are mixed and ground with graphite-phase carbon nitride nanosheets to realize mechanical chemical pre-reaction. Then, low-temperature freezing treatment is performed, and the mixture after the freezing treatment is calcined in an inert atmosphere to realize in-situ synthesis of perovskite quantum dots on the carbon nitride nanosheets. The calcined sample is sequentially subjected to water washing, alcohol washing, and then drying to obtain a perovskite quantum dot / graphite-phase carbon nitride nanosheet composite material. The synthesis of the quantum dots is directly synthesized under high-temperature solid-phase conditions without adding ligands, the quantum dots have few interface defects with the carbon nitride, which is beneficial to carrier transmission and eliminates the influence of ligands on photo-generated carriers.

The application discloses an olefin-connected pyridyl covalent organic framework material and a preparation method and application thereof, and belongs to the technical field of photocatalysis. The material is formed by olefin bridging of 2,4,6-trimethyl-1,3,5-triazine monomers and aromatic aldehyde monomers containing pyridine units and bipyridine units, and 2,4,6-trimethyl-1,3,5-triazine, pyridine-2,5-dimethyl formaldehyde or 2,2'-bipyridine-5,5'-dimethyl formaldehyde are heated and reacted under sealed conditions; after the reaction is completed, natural cooling to room temperature is carried out, vacuum filtration is carried out and filter residues are collected, washing is carried out, and vacuum drying is carried out, and the material is obtained. The pyridine and bipyridine units are used for constructing different oxygen adsorption modes of Pauling type and Yeager type respectively, the oxygen reduction reaction path is changed, a two-step single electron path and a one-step two electron path are realized, the photocatalytic efficiency is effectively improved, and the material has a wide application prospect as a photocatalyst for photocatalytic oxygen reduction and synthesis of hydrogen peroxide.

The utility model belongs to the technical field of hydrogenation devices, and particularly relates to a catalytic hydrogenation continuous production device which comprises a hydrogenation tank, an installation frame is arranged on the front side of the hydrogenation tank, a hydrogen storage tank is arranged on the right side of the hydrogenation tank, and a hydrogen pump is arranged between the hydrogenation tank and the hydrogen storage tank. Hydrogen in reaction tail gas and steam in a product are separated step by step through the hydrogen backflow assembly, so that the hydrogen is prevented from carrying moisture to influence the purity, the treated hydrogen is pressurized by the hydrogen compressor and then returns to the hydrogen storage tank to be mixed with fresh hydrogen for recycling, the hydrogen recovery rate is improved, and the energy consumption is reduced. Raw material consumption is remarkably reduced, tail gas emission is reduced, the environment-friendly requirement is met, uniform, quantitative and uninterrupted addition of a catalyst is achieved through the dosing assembly, shutdown operation is not needed, a pressure gauge at the top of the hydrogenation tank monitors pressure in real time, hydrogen inlet amount is adjusted in a linkage mode, constant reaction is maintained, the stable reaction rate is ensured, and continuous production is achieved.

This invention discloses a TiO2-based photocatalytic material derived from a metal-organic framework (MOF), its preparation method, and its applications, belonging to the field of photocatalysis. Using a titanium-based MOF as a template, a heterojunction photocatalytic material of TiO2 and ZnIn2S4 was prepared via a one-pot method in a ZnIn2S4 synthesis precursor solution. The MOF-derived TiO2 possesses extremely high specific surface area and porosity, significantly promoting O2 capture. Furthermore, the heterojunction material prepared via the one-pot method exhibits excellent interfacial contact between monomers, facilitating the separation of photogenerated carriers and further promoting the photocatalytic reaction. This photocatalytic material, used for the photocatalytic reduction of O2 to H2O2 under visible light, offers advantages such as simple preparation and high visible light catalytic activity, providing a green and sustainable pathway for oxygen reduction to H2O2.

The utility model discloses an oxidizing tower for producing and preparing hydrogen peroxide, which relates to the technical field of hydrogen peroxide production and comprises a tower body mechanism, a spraying mechanism is arranged in the tower body mechanism, and an oxidizing mechanism is arranged below the spraying mechanism and on the inner wall of the tower body mechanism. The oxidation mechanism comprises an oxygen supply pipe externally connected with oxygen supply equipment, and an oxygen supply branch pipe is arranged on the surface of the oxygen supply pipe. Through the arrangement of the oxidation mechanism, when a reaction liquid is oxidized, oxygen in the oxygen supply pipe is introduced into the microporous aeration stone through the oxygen supply branch pipe, and under the action that the interior of the microporous aeration stone is provided with micropores, the oxygen is divided into fine airflow, so that the contact area with the reaction liquid is increased; the reaction liquid can be differentiated into fine liquid drops through the spraying micropores in the surface of the flow dividing pipe and then sprayed out, so that the contact area of the liquid and the gas is increased again, the oxidation effect is improved, and the oxidation is more comprehensive.

The present invention relates to metal halide perovskite (CsPbBr3) nano / microcrystals. Specifically, the present invention relates to a method for the synthesis of metal halide perovskite (CsPbBr3) nano / microcrystals. The present invention uses an easy, scalable low temperature growth of metal halide nanoparticles like CsPbBr3. The method uses a clever play on the solubility and ion exchange mechanism to precipitate nano and microcrystals of metal halide perovskites. The synthesis resulted in stable perovskite crystals with high photo- luminescence, ultralow dark current and control over their morphology. The combination of ultralow dark current, high responsivity, exceptional detectivity, and broad-band photon detection capabilities makes these crystals an excellent choice for upcoming sensors and detector technologies.

The invention discloses a metamaterial optical fiber and a preparation method and application thereof.The metamaterial optical fiber comprises an optical fiber body and a coating, the coating is located on at least part of the surface of the optical fiber body, the coating comprises skeleton particles and photocatalytic active particles, and the average particle size of the skeleton particles is larger than that of the photocatalytic active particles. According to the application, the small-particle-size photocatalytic active particles and the large-particle-size skeleton particles are combined and formed on at least part of the surface of the optical fiber body, so that the loading capacity and the adhesion firmness of the photocatalytic active particles on the optical fiber body are improved, and the photocatalytic efficiency of a system is improved.

An improved method for reducing and preventing healthcare associated infections is provided, comprising attaching one or more dry hydrogen peroxide (DHP) generators to a medical procedure area, generating DHP, and maintaining a concentration of between 1.0 parts per billion (ppb) and 200 ppb.

This invention discloses a method for preparing a hollow double-shell structured material composed of transition metal sulfides and covalent organic frameworks (COFs). The method includes the following steps: adding a hollow transition metal sulfide, a COF precursor, a first organic solvent, and an aqueous solution of an inorganic acid to a Schlenk tube; ultrasonically treating the resulting mixture for 10-60 minutes to remove air; and reacting at 100-200°C for 3-7 days; washing and vacuum drying the resulting solid powder to obtain a hollow double-shell structured material formed by the composite of transition metal sulfides and COFs. The hollow double-shell structured material obtained by this invention effectively integrates the advantages of COFs and transition metal sulfides, enhancing the visible light absorption range, accelerating the separation and migration of photogenerated carriers, and increasing the number of active sites for proton reduction, thereby improving the performance of photocatalytic reactions.

The invention discloses a preparation method of a high-activity porous carbon ORR catalyst without transition metal doping. The preparation method comprises the following steps: adding sodium citrate, urea and ZnCl2 into absolute ethyl alcohol for ultrasonic treatment, and then stirring and drying in a water bath to obtain N-rich gel coated solid-phase sodium citrate; the preparation method comprises the following steps: carrying out stepped temperature-programmed pyrolysis on a porous carbon precursor under the protection of an inert atmosphere, sequentially carrying out acid washing, water washing and alcohol washing on a pyrolysis product, carrying out suction filtration to collect the product, and drying to obtain the porous carbon ORR catalyst without transition metal doping. According to the method, sodium citrate is used as a carbon source, urea is used as a nitrogen source, ZnCl2 is introduced as a pore forming agent and an active agent, and the metal-free porous carbon material with high catalytic activity and stability is successfully constructed through stepped pyrolysis. Experiments show that the catalyst shows ORR catalytic activity and excellent electrochemical stability which are equivalent to those of commercial 20% Pt / C in an alkaline environment.

A method of making a mesoporous single metal atom catalyst is provided, the method comprising: (a) forming a layer of silica on surfaces of a zeolitic imidazolate framework (ZIF) material to provide a silica coated ZIF material; (b) pyrolyzing the silica coated ZIF material to provide a pyrolyzed silica coated ZIF material; removing the layer of silica from the pyrolyzed silica coated ZIF material to provide an etched ZIF material; and oxidizing the etched ZIF material to provide a mesoporous single metal atom catalyst. The mesoporous single metal atom catalysts and electrolyzers and cascade systems comprising the catalysts are also provided. Methods of using the electrolyzers and cascade systems are also provided.

The application relates to a preparation method and application of a cerium monatomic-anchored polyhydroxyl porphyrin covalent organic framework-based photocatalyst, and relates to a preparation method and application of a photocatalyst. The application aims to solve the problems that the existing technology has low light-generated carrier separation efficiency, lacks oxygen adsorption sites and catalytic active centers for oxygen reduction in preparation of a porphyrin-based covalent organic framework photocatalyst. In the application, a ligand 5, 10, 15, 20-tetrakis(4-aminophenyl) porphyrin and a linker 2, 5-dihydroxy terephthaldehyde are selected in a preparation stage, an imine condensation reaction is carried out under the action of an acetic acid initiator to form an imine bond, and the introduction of a carboxyl group is realized through a Doebner three-component reaction of pyruvic acid. The pyruvic acid serves as a nucleophilic reagent, attacks a carbon atom in the imine bond, and nucleophilic addition-cyclization-aromatization are carried out to produce a 4-carboxy quinoline bond, so that a polyhydroxyl porphyrin COF catalyst is formed. The polyhydroxyl porphyrin COF is adsorbed with cerium atoms in methanol in which nitric acid cerium is dissolved, stirring is carried out, and finally, a cerium monatomic-anchored polyhydroxyl porphyrin COF photocatalytic material is formed.

The invention relates to modified carbon nitride as well as a preparation method and photocatalytic application thereof, and the modified carbon nitride is prepared by grafting 2, 5-dibromobenzene-1, 4-dimethyl into g-C3N4 molecules or fragments. According to the modified g-C3N4 provided by the invention, green and efficient synthesis of H2O2 by g-C3N4 series catalysts can be realized under the conditions of no sacrificial agent and no aeration, the generation rate of H2O2 is increased by the modified g-C3N4 provided by the invention, the generation rate of H2O2 is not obviously reduced after the modified g-C3N4 is recycled for multiple times, and the modified g-C3N4 has excellent stability, is wide in application range, and is suitable for industrial production. The method can be suitable for a wide pH value range and various complex water quality, and can achieve an extremely high removal rate for degradation of pollutants.

The utility model relates to a vaporized hydrogen peroxide generating device which comprises an air input mechanism (1), a vaporized hydrogen peroxide loading mechanism (2) and a dehumidification cracking mechanism (3), the air input mechanism (1) is provided with an air input port, and the vaporized hydrogen peroxide loading mechanism (2) is provided with an air output port; the air input mechanism (1) is connected with the vaporized hydrogen peroxide loading mechanism (2) and the dehumidification cracking mechanism (3) through the three-way valve (4), and the dehumidification cracking mechanism (3) is connected with the hydrogen peroxide loading mechanism (2) and the discharge pipe (6) through the three-way discharge valve (5). Compared with the prior art, the device disclosed by the utility model has the advantages that carrier gas containing vaporized hydrogen peroxide can be generated, and switching between sterilization and degradation functions can be realized.

The invention relates to the field of catalyst materials, in particular to a catalyst for efficient catalytic synthesis of hydrogen peroxide as well as a preparation method and application thereof. A catalyst for efficient catalytic synthesis of hydrogen peroxide comprises a porous carrier and alloy sites loaded on the surface of the functional carrier, and the alloy sites are Pd-Cu bimetallic monatomic alloy sites. Pd-Cu bimetallic monatomic alloy sites are adopted, and through the synergistic effect of two metal atoms, the electron density and coordination environment of an active center can be precisely regulated and controlled, the oxygen reduction reaction path is optimized, and side reactions are inhibited; meanwhile, the monatomic alloy structure can maximize the exposure degree of active sites and improve the catalytic efficiency. According to the scheme, starting from the composition and structural design of an active center, aiming at the core defects that the activity and selectivity of the existing catalyst are difficult to consider and the dispersity is poor, through the synergistic effect of a bimetallic monatomic alloy and the bearing effect of a porous carrier, the catalyst is prepared.

The present application relates to the field of photocatalyst, discloses a carbon and nitrogen coated transition metal cluster photocatalyst and its preparation method and application, the method comprises the following steps: in the presence of organic solvent, mixing transition metal nitrate and diamino maleonitrile, then the mixture is hydrothermally reacted to obtain a solid product; the transition metal nitrate is selected from at least one of cobalt nitrate, iron nitate and copper nitrate; the molar ratio of transition metal nitrate and diamino maleonitrile is 1:1-3; the hydrothermal reaction conditions include: temperature is 120-140 DEG C, time is 8-15h; under the protection of inert gas, the solid product is calcined, and then the calcined product is pickled; the calcination conditions include: the temperature rising rate is 3-10 DEG C / min, the temperature is 450-700 DEG C, and the time is 1-4h. The photocatalyst obtained by the method can catalyze the production of hydrogen peroxide and catalyze 1,5-dihydroxynaphthalene oxidation to produce juglone, and the yield of the product is higher.

The invention relates to a preparation method of a piezoelectric electro-catalyst easy to recycle, the prepared catalyst and application, and belongs to the technical field of piezoelectric electro-catalysis. The method comprises the following steps: preparing KNbO3 powder through a molten salt method; then, the nano Fe3O4 is pinned into the KNbO3 powder through plasma ball milling; then carrying out hydrogenation treatment to obtain KNbO3-Fe3O4 composite powder; and finally, controllably depositing a layer of photocatalytic film on the surface by adopting an atomic layer deposition technology so as to obtain the composite catalyst with a core-shell structure. The prepared piezoelectric photocatalyst has excellent piezoelectric catalysis and photocatalytic activity, and is easy to realize rapid separation and recovery through magnetic separation. The catalyst can be applied to sewage treatment, hydrogen production, hydrogen peroxide production or carbon dioxide reduction.