485 results about "Water splitting" patented technology

The invention discloses a preparation method of a rare earth element doped nickel-based selenide nano-material and application of the rare earth element doped nickel-based selenide nano-material in electro-catalysis water full-hydrolysis reaction. According to the method, nickel salt, cerium salt, selenium dioxide and potassium chloride are prepared into electrolyte, and the electrolyte is subjected to electro-deposition on a foamed nickel substrate to obtain Ce-doped Ni0.85Se nanoparticles growing on foamed nickel. The crystal structure and electron distribution of Ni0.85Se are optimized by doping trace rare earth element cerium, so that the HER and OER performances of the Ni0.85Se are greatly improved. The prepared catalyst is self-supporting closely-packed nanoparticles, the formed amorphous structure is easy to expose more active sites, the catalyst has good electrocatalytic hydrogen evolution and oxygen evolution performance under alkaline conditions, the overpotential in electrocatalysis of nickel-based selenide is greatly reduced, and the electrocatalytic performance of nickel-based selenide is improved. And excellent electro-catalytic activity is shown in electro-catalytic water full hydrolysis. And the self-supporting electrode is not easy to fall off due to generation of bubbles in the reaction process, so that the working stability of the catalyst is improved.

The invention relates to a catalyst for the hydrogen evolution reaction (HER) and methods for using the catalyst in a water-splitting process. A hydrogen evolution reaction (HER) electrocatalyst, and a method and use for preparing a HER electrocatalyst are disclosed. The method comprises the step of forming a two-dimensional electron gas (2DEG) interface at a heterojunction of at least one of two or more alternating layers of a first complex oxide and a second complex oxide, wherein the or each 2DEG interface exhibits a current density, corresponding to an intrinsic hydrogen evolution reaction (HER) activity that renders the 2DEG interface(s) suitable as an HER electrocatalyst for producing hydrogen (H2) from a water-based electrolyte by water electrolysis.

The invention belongs to the field of preparation of nano materials, and discloses a CoP / Co (OH) 2 sea urchin-shaped heterojunction catalyst growing on foamed nickel and a preparation method and application of the CoP / Co (OH) 2 sea urchin-shaped heterojunction catalyst. Alkali cobalt carbonate (CoCH) is used as a precursor, a crystalline phase CoP substrate is generated through a low-temperature phosphating method, then the surface of the crystalline phase CoP substrate is uniformly coated with an amorphous Co (OH) 2 layer through an electro-deposition process, and the self-supporting phosphating / hydroxyl heterogeneous structure catalyst (CoP / Co (OH) 2) is successfully constructed. The obtained CoP / Co (OH) 2 shows excellent complete water splitting performance, and is benefited from the high-activity specific surface area (Cdl = 44.66 mF cm <-2 >) and the interface rapid electron conduction characteristic (Rct = 0.43 omega) of a heterogeneous structure; when two electrodes are assembled to fully decompose water, the cell voltage is only 1.780 V when the current density is 250 mA cm <-2 >, and after continuous operation is carried out for 24 hours, the performance is basically kept unchanged, and the voltage fluctuation ratio is lower than 0.5%. CoP / Co (OH) 2 is prepared into a 2 * 2cm < 2 > self-supporting electrode to construct AEMWE, only 2.08 V cell voltage is needed under the ultrahigh current density of 1A cm <-2 >, the AEMWE can stably run for 250 hours, the attenuation rate is 80 mu V h <-1 >, meanwhile, the hydrogen production efficiency is calculated to reach 96.2% through gas metering and Faraday law, and the engineering potential of the AEMWE in large-scale hydrogen production application is verified.

The present invention discloses a preparation method and application of a MOF-on-MOF heterojunction metal-organic framework material rich in oxygen defects, belonging to the technical field of electrocatalytic oxygen evolution reaction. The present invention first grows Ni NDC nanosheets in situ on a carrier by a solvothermal method, and then grows Fe BDC nanosheets on the surface of the Ni NDC nanosheets by a solvothermal method to form Ni NDC@Fe BDC ultra-thin nanosheets. This method can synthesize a MOF-on-MOF type metal-organic framework under the premise of lattice mismatch. The synthesized Ni NDC@Fe BDC combines the advantages of multi-component material hybridization, ultra-thin nanosheets and defect induction, which can increase the number of active sites and promote the rapid transfer / redistribution of electrons in the catalytic process. The MOF-on-MOF heterojunction metal-organic framework has good electrocatalytic performance and excellent total water decomposition performance in alkaline oxygen evolution reaction.

The invention belongs to the technical field of water purification, and particularly discloses commercial filtering type magnetization water purification equipment which comprises a first magnetization body, a second magnetization body and a water purification device. And the plurality of magnets are arranged outside the magnetized body at intervals in the circumferential direction. When the water flow moves along the spiral flow channel, the water flow not only rotates along with the flow channel, but also continuously cuts the surrounding magnetic induction lines, compared with a traditional linear flow channel, the relative movement of the water flow and the magnetic induction lines is more complex, hydrogen bonds among water molecules can be more effectively broken, macromolecular group water is decomposed into micromolecular group water, and the permeability and solubility of the water are improved.

A nanocomposite catalyst for use as an electrode in water electrolysis includes a cobalt triazole (Co-Tri) metal-organic framework (MOF), carbon quantum dots (CQDs), carbon nanosheets (CNs), and an ionically conductive polymer binder. The mass ratio of the nanocomposite catalyst includes cobalt triazole metal-organic framework to the carbon quantum dots is in the range of 1:2 to 1:4, and the mass ratio of the cobalt triazole metal organic framework to the carbon nanosheets mass ratio is in the range of 1:4 to 1:6. The nanocomposite catalyst includes current density less than or equal to (≤) −5 milliampere per centimeter square (mA·cm−2) at an applied potential of −100 millivolts (mV) when catalyzing the hydrogen evolution reaction (HER) in water electrolysis.

The invention discloses a preparation method and application of a bimetallic sulfide / three-dimensional porous carbon catalyst, and relates to the technical field of electrolyzed water catalysts.The preparation method comprises the following steps that melamine sponge is cleaned, and the clean melamine sponge is obtained; the preparation method comprises the following steps: dissolving metal salt 1 and metal salt 2 in an ethanol aqueous solution, and adding alkali and an aniline monomer to obtain a precursor solution; completely soaking the clean melamine sponge in a precursor solution, carrying out constant-temperature hydrothermal reaction, and sequentially washing and drying to obtain the melamine sponge anchored with bimetal ions; introducing inert gas for protection, and performing high-temperature vulcanization treatment to obtain the three-dimensional porous carbon catalyst embedded with the bimetallic sulfide heterostructure. The catalyst comprises uniformly dispersed bimetallic sulfide nanoparticles and a spongy three-dimensional porous carbon carrier, shows excellent bifunctional catalytic activity and stability when being applied to an electro-catalytic water decomposition reaction, and has a wide application prospect.

The invention relates to a high-entropy perovskite material and a preparation method and application thereof, the chemical formula of the high-entropy perovskite material is ABO3, the A-site element is La element, and the B-site element is selected from 5-10 transition metal elements; the high-entropy perovskite material has a two-dimensional Tailing structure, nano-particles are arranged in a cross-linking manner, and gaps are formed among the particles. Compared with the prior art, the two-dimensional Turing structure high-entropy perovskite material is endowed with excellent electro-catalytic water decomposition hydrogen production performance due to unique morphology and components, is adaptive to fluctuation power of clean energy such as wind energy and solar energy, and has a wide industrial application prospect.

The application discloses a preparation method and application of a ferroelectric full water-splitting photocatalyst. The preparation method comprises the following steps: S1: pretreating a ferroelectric material to obtain a pretreated ferroelectric material; S2: after atomic layer deposition of the pretreated ferroelectric material and a metal organic complex source material, non-active gas I is introduced to perform blowing I, water is introduced, non-active gas II is introduced again to perform blowing II, and the first deposition is completed; and S3: according to the thickness of the ferroelectric full water-splitting photocatalyst, the step S2 is circularly performed to obtain the ferroelectric full water-splitting photocatalyst. The ferroelectric material can efficiently photocatalyze full water splitting through accurate regulation and modification of the surface of the ferroelectric material by the atomic layer deposition technology. The method not only provides an experimental basis for researching the limiting factors of the ferroelectric material in a photocatalytic reaction, but also provides a new idea for constructing an efficient photocatalyst by using efficient charge separation and depolarization electric field of the ferroelectric material.

A nanocomposite material including iron sulfide (FeS2) nanoparticles, iron oxide (α-Fe2O3) nanoparticles, titanium dioxide (TiO2) nanoparticles, and graphitic carbon nitride (C3N4) nanosheets and a method of its preparation. The nanocomposite is used in a method of forming oxygen gas from water using an applied voltage and photoirradiation, a method of forming hydrogen gas from water using an applied voltage and photoirradiation, and a method of photodegrading organic pollutants using visible light photoirradiation.

The invention relates to the technical field of photo-anodes, in particular to a composite photo-anode with transition metal ions embedded into phosphoric acid small organic molecules and a preparation method of the composite photo-anode. The preparation method comprises the following steps: S1, soaking a bismuth vanadate photo-anode in a phosphoric acid small organic molecule solution, and then performing annealing treatment to obtain a phosphoric acid small organic molecule / photo-anode; and S2, soaking the phosphoric acid small organic molecule / photo-anode in a transition metal salt solution to obtain the composite photo-anode. According to the invention, hole storage and transmission functions of polyphosphoric acid small organic molecules and surface rapid water oxidation reaction kinetics of metal ions are synergistically utilized, on one hand, the electron-hole separation efficiency of bismuth vanadate is improved through hole storage, and on the other hand, surface hydroxyl groups of the polyphosphoric acid small organic molecules and transition metal ions are anchored; bismuth vanadate surface electron-hole separation and water oxidation kinetics are synergistically enhanced, charge recombination is synergistically inhibited, charge transfer power is promoted, and the photocurrent density and the water decomposition hydrogen production capacity of the photoanode are improved.

To provide a carbon dioxide recovery desorption concentration device and a carbon dioxide recovery desorption concentration method capable of efficiently recovering and concentrating carbon dioxide with low energy consumption by separating carbon dioxide from water decomposition products in recovery of carbon dioxide from carbon dioxide-containing gas utilizing electrochemical reactions.SOLUTION: A carbon dioxide recovery desorption concentration device 1 performs recovery of carbon dioxide from carbon dioxide-containing gas and desorption of the recovered carbon dioxide using intermittently progressed water electrolysis reactions to concentrate carbon dioxide.SELECTED DRAWING: Figure 1

The invention belongs to the field of nano material preparation, and discloses a nickel-molybdenum-iron compound growing on foamed nickel and a preparation method and application of an anion exchange membrane. The difunctional electrocatalyst Ni2P / MoOx / Fe2P with an amorphous MoOx and crystal Ni2P / Fe2P heterogeneous structure is prepared through a hydrothermal-etching-phosphating method. Ni2P / MoOx / Fe2P is used as a cathode and an anode, an overall water decomposition (OWS) performance test is carried out in an electrolyte containing 1M of KOH, and the required voltage is only 1.815 V when the current density reaches the large current density of 250mA cm < 2 >. This is attributed to sufficient active sites, abundant phase interfaces and a unique nanorod array structure in the nickel-molybdenum-iron compound. The material still has excellent stability under the ultrahigh constant current density of 500 mA cm < 2 >. The PVA / PDDA-OH <-> membrane with anion selectivity is prepared through physical crosslinking of PVA and PDDA, and the PVA / PDDA-OH <-> membrane has good OH <-> conductivity. The anion exchange membrane water electrolyzer assembled by using the Ni2P / MoOx / Fe2P catalyst and PVA / PDDA-OH <-> stably operates for 250 hours under the current density of 1 A cm <-2 >, the hydrogen production Faraday efficiency is about 94.8% through calculation, and the potential of the anion exchange membrane water electrolyzer in the actual application of large-current hydrogen production is highlighted.

The present invention provides an oxygen-dominated supra-nano dual-phase catalytic reaction material, which includes a uniform oxygen-enriched amorphous shell and a core encapsulated within the uniform oxygen-enriched amorphous shell. This invention exhibits ultrahigh HER performance, a critical reaction in water splitting, making it suitable for application in hydrogen production industries, battery companies, new energy vehicle enterprises, and large power stations.

The invention relates to an island energy system based on deep reinforcement learning. The island energy system comprises an energy device, an electrolysis device, an energy storage battery, a hydrogen storage device, an oxygen storage device, a pressure swing adsorption device, an ammonia synthesis device, a seawater desalination device and a scheduling device, the energy device inputs electric energy to the electrolysis device, the energy storage battery, the pressure swing adsorption device and the seawater desalination device; the electrolysis device is used for decomposing water provided by the seawater desalination device into hydrogen and oxygen; the pressure swing adsorption device provides nitrogen; the hydrogen storage device stores hydrogen, and then the hydrogen and nitrogen are input into the ammonia synthesis device; the oxygen storage device stores oxygen; the scheduling device constructs the real-time operation state of the system into a multi-dimensional state vector, forms an electricity-hydrogen-oxygen-ammonia-water multi-energy flow coupled balance constraint system, makes a decision on the multi-dimensional state vector based on a near-end strategy optimization algorithm, and outputs an optimal strategy parameter. According to the system, the electrolysis device serves as a hub, the global relation between electrolysis hydrogen production and multi-energy combined supply is optimized, and the low-carbon energy supply, ecological restoration and load requirements are met.

The invention provides a preparation method of a cobalt-based intermetallic carbide material and application of the cobalt-based intermetallic carbide material in a preparation method of an electrocatalytic nitrate reduction electrolytic tank or a zinc-nitrate battery. The preparation method of the cobalt-based intermetallic carbide material comprises the following steps that cobalt chloride hexahydrate, indium chloride tetrahydrate, dicyandiamide and ketjen black are ground and mixed and then put into a tubular furnace for thermal annealing reduction, and the cobalt-based intermetallic carbide material is obtained. According to the method, cobalt-based intermetallic carbide material Co3InC0.75 powder is prepared into slurry, the slurry is dropped on carbon paper to be used for an electro-catalysis reaction, the material strengthens nitrate adsorption and water decomposition and inhibits a hydrogen evolution reaction, and therefore the performance of electro-catalysis of nitrate reduction to produce ammonia is improved.

The invention relates to a composite catalyst for hydrogen evolution of an anion exchange membrane electrolytic cell and a preparation method of the composite catalyst, and belongs to the technical field of electrocatalysts. A transition metal M1-M4 precursor and a Pt precursor are impregnated and adsorbed to a carbon carrier loaded with a rare earth oxide, then the carbon carrier is placed in an inert atmosphere for annealing, the carbon-loaded platinum-based high-entropy cluster / rare earth oxide nanoparticle composite catalyst PtM1M2M3M4 / ReOX / C is prepared, and M1-M4 is any combination of transition metal Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, W or Mo. By utilizing the characteristic that the rare earth oxide can promote water decomposition and anchor clusters under the alkaline condition, the prepared catalyst can remarkably improve the hydrogen evolution reaction (HER) electrocatalytic activity and long-term stability under the alkaline condition, shows excellent performance in an anion exchange membrane electrolytic cell and keeps long-term stable operation under the industrial-grade current density.

The invention discloses a foamed nickel loaded cross cluster-shaped multi-metal phosphide. NiCoFeP is obtained by compounding Ni2P, CoP and FeP. The invention further discloses a preparation method of the foamed nickel loaded cross cluster-shaped multi-metal phosphide. The preparation method comprises the following steps: preparing Ni (OH) 2 / NF which is vertically arranged on the surface of foamed nickel NF in situ through a nickel source and has a nano lamellar structure thickness of 30-40nm, then preparing NiCoFe-LDH / NF with a cross-cluster-shaped structure thickness of 160-180nm in situ through a cobalt source and an iron source, and finally, phosphorizing through a phosphorus source to prepare NiCoFeP / NF with a cross-cluster-shaped structure thickness of 30-50nm. When the catalyst is used as a water electrolysis OER / HER bifunctional catalyst, the OER overpotential is 210-220 mV under the condition that the current density is 50 mA cm <-2 >, and the HER overpotential is 140-150 mV under the condition that the current density is 20 mA cm <-2 >. When the catalyst is used as a complete water splitting catalyst, the current density can be 10mA cm <-2 > under the condition that the potential is 1.51 V; under the condition that the current density is 50mA cm <-2 >, the operation time is 96 hours, and the potential is 1.81 V; and compared with the initial potential, the potential is only reduced by 5%, namely, the performance attenuation can be ignored.

The invention belongs to the field of electro-catalytic materials, and particularly relates to a bifunctional electro-catalytic water decomposition material and preparation and application thereof.The preparation method includes the steps that a first MOF precursor material is subjected to a first-stage coordination reaction in a solution containing an auxiliary a and an auxiliary b, and a first MOF is obtained; the first MOF is used as a substrate, a second-stage coordination reaction is carried out on a second MOF precursor material in a solution of an auxiliary c, the second MOF is deposited on the first MOF, and a core-shell double-MOF material is prepared; performing heat treatment on the core-shell dual-MOF material to obtain a heat-treated material; and mixing the heat treatment material with a phosphorus source, carrying out phosphating roasting treatment, and putting a phosphating product into a liquid-phase cooling medium while the phosphating product is hot, and carrying out quenching treatment, so as to obtain the bifunctional electro-catalytic water decomposition material. The bifunctional electro-catalytic water decomposition material prepared by the preparation method disclosed by the invention has excellent HER and OER dual catalytic activity.

An electrode includes a transparent substrate, and a layer of a nanostructured material at least partially covering a surface of the transparent substrate. The nanostructured material includes defective perovskite nanostructures (DPNSs) in the form of nanoplates having an average particle size in a range of 10 to 100 nanometers (nm), an interplanar spacing d(101) of the (101) plane in a range of 0.3 to 0.4 nm, and an interplanar spacing d(104) of the (104) plane in a range of 0.2 to 0.3 nm. A method of making the electrode.

The invention relates to the technical field of photoelectrocatalysis, in particular to a Mn (II) coordination polymer photoelectrode crystalline material and a preparation method and application thereof. The Mn (II) coordination polymer {[Mn2 (H2O) 6 (DODDA)]. 4H2O} n is obtained from an H4 (DODDA) organic ligand and manganese salt through a solvothermal method, an asymmetric unit comprises two Mn (II) ions in different coordination modes, adjacent Mn2 ions are bridged through carboxyl oxygen of the ligand to form straight chains, and two adjacent Mn2 straight chains are further bridged with Mn1 through the H4 (DODDA) ligand to form a transverse trapezoidal one-dimensional chain. A three-dimensional supramolecular structure is formed among the one-dimensional chains through the interaction of a large number of intermolecular hydrogen bonds. The Mn (II) coordination polymer shows better photoelectric property, has the potential of serving as a photoelectrode material, has good optical and electrical characteristics, can be used for constructing an efficient photoelectrocatalysis water decomposition system, and has application prospects in the aspects of photocatalytic hydrogen production, solar energy conversion and the like.

The invention relates to the technical field of catalysts, in particular to a layered transition metal doped composite structure alkaline electrolytic water hydrogen production efficient catalyst and a preparation method and application thereof.The catalyst is of a layered nickel-cobalt-iron-phosphorus doped composite structure, the chemical formula of the catalyst is Ni1-x-yCoxFeyPa (OH) 2-a / rGO (wherein x is larger than or equal to 0.1 and smaller than or equal to 0.3, y is larger than or equal to 0.05 and smaller than or equal to 0.2, a is larger than or equal to 0.02 and smaller than or equal to 0.1, and the mass ratio of rGO is 5%-15%), the structure is characterized in that layered Ni (OH) 2 is used as a main body, Co < 2 + > and Fe < 3 + > replace part of Ni < 2 + > to form active sites, P is embedded between layers in the form of PO4 < 3-> to form a pillar effect, and the layered structure and rGO are combined through Van der Waals force to form the composite heterojunction. The preparation method comprises the following steps: metal salt dissolution, dispersion of a phosphorus source and GO, pH adjustment, hydrothermal reaction and post-treatment. The catalyst has excellent hydrogen evolution and oxygen evolution dual-function activity in an alkaline water electrolysis reaction, the HER overpotential is smaller than or equal to 75 mV, the OER overpotential is smaller than or equal to 245 mV and the overall water decomposition voltage is smaller than or equal to 1.55 V in 1 mol / L KOH under the current density of 10 mA / cm < 2 >, and the overpotential amplification is only 4.7% in a 100 h stability test.

This invention belongs to the field of electrocatalytic materials, specifically relating to bifunctional electrocatalytic water splitting materials and their preparation and application. The preparation steps include: performing a first coordination reaction on a first MOF precursor material in a solution containing promoter a and promoter b to obtain a first MOF; using the first MOF as a substrate, performing a second coordination reaction on a second MOF precursor material in a solution containing promoter c to deposit the second MOF onto the first MOF, thus obtaining a core-shell bifunctional MOF material; subjecting the core-shell bifunctional MOF material to heat treatment to obtain a heat-treated material; then mixing the heat-treated material with a phosphorus source for phosphating and calcination, and rapidly cooling the phosphating product while hot in a liquid-phase cooling medium to obtain the bifunctional electrocatalytic water splitting material. The bifunctional electrocatalytic water splitting material prepared by the method of this invention exhibits excellent dual catalytic activity for both HER and OER.

The application provides a one-dimensional iron oxide nanorod heterojunction composite material and a preparation method and application thereof, and belongs to the technical field of photoelectrocatalytic water splitting hydrogen production. The composite material provided by the application comprises: one-dimensional iron oxide nanorods, cuprous sulfide nanoparticles loaded on the one-dimensional iron oxide nanorods, and cobalt hydroxide nanosheets coated on the surfaces of the one-dimensional iron oxide nanorods and the cuprous sulfide nanoparticles. On one hand, the Fe2O3 / Cu2S p-n heterojunction is introduced to accelerate the separation of photo-generated carriers in the Fe2O3 nanorod array, and on the other hand, the Co(OH) x The surface OECs accelerate the kinetics process of interfacial water oxidation, the rapid depletion of photo-generated holes further improves the charge separation of the photoanode surface, and the synergistic effect between the Fe2O3 / Cu2S p-n heterojunction and the OECs significantly improves the PEC water splitting performance of the iron oxide nanorod array composite material.

Low-cost and earth abundant, Ni1-xMox alloy nanocrystals, with sizes ranging from 18-43 nm and varying Mo composition (0.0-11.4%), were produced by a colloidal chemistry method for alkaline HER reactions. For a water splitting current density of −10 mA / cm2, these alloys demonstrate over-potentials of −62 to −177 mV, which are comparable to commercial Pt-based electrocatalysts (−68 to −129 mV). The cubic Ni0.934Mo0.066 alloy nanocrystals exhibit the highest activity as alkaline HER electrocatalysts, outperforming commercial Pt / C (20 wt %) catalyst.

An electrocatalyst that includes a carbon cloth (CC) substrate including carbon fibers having a mean diameter of 2.5 to 25 micrometer (μm), and a catalyst disposed on the CC substrate, the catalyst including a conductive metal-organic framework (MOF) including a metal and triazole structural units, and a metal sulfide including the metal disposed on the conductive MOF. The catalyst is present as structures having a mean size of 2.5 to 25 μm and a surface texture having projections having a mean size of 100 to 500 nanometer (nm). The electrocatalyst is used in a method of forming hydrogen via the HER and a method of forming oxygen via the OER.

According to the low-carbon ironmaking system and method based on chemical-looping water splitting, in the low-carbon ironmaking system based on chemical-looping water splitting, an oxygen-enriched blast furnace-converter ironmaking module can treat and process iron ore into steel products, and generated steel gas can be used by the system subsequently; the steel gas electrolysis and mixing module is used for treating blast furnace gas by using a high-temperature carbon dioxide electrolytic tank, and recycling the treated mixer to a tuyere at the bottom of the furnace to reduce fossil fuel consumption, and the residual steel gas is mixed after being pretreated; and the chemical-looping water splitting combined heat and power generation module adopts the mixed steel gas to generate high-purity carbon dioxide and hydrogen under the action of a chemical looping. The carbon dioxide is stored after being compressed and dehydrated, and the hydrogen realizes cogeneration in the fuel cell and supplies energy to the whole system. The system reduces the dependence of a low-carbon ironmaking process on green electricity, and has the advantages of high efficiency, low emission and the like.

This invention provides a three-dimensional carbon nitride photocatalyst with an advanced structure, its preparation method, and its application, relating to the field of photocatalyst technology. The preparation method includes: obtaining graphitic carbon nitride through thermal condensation and nitrogen-rich precursor polymerization; mixing the graphitic carbon nitride in a polyphenol solution, then adding Tris-HCl solution dropwise and stirring to react, causing the polyphenols to polymerize in situ on the surface of the graphitic carbon nitride to form a polyphenol coating; separating and drying the coating to obtain a composite intermediate; mixing and grinding the composite intermediate with molten salt, then calcining it under a protective atmosphere at 400-650℃ to obtain the three-dimensional carbon nitride photocatalyst with an advanced structure. The preparation method provided by this invention is green and environmentally friendly, using readily available and inexpensive raw materials. Simultaneously, the reaction conditions are mild, requiring no template agent. The resulting catalyst has an advanced structure and exhibits extremely high photocatalytic activity for water splitting to produce hydrogen and excellent stability at room temperature and pressure, showing promising application prospects and economic benefits.

The invention discloses a vector calculation-based water meter water quantity and water rate calculation method, and aims to solve the technical problems of I / O bottleneck, high calculation delay and poor expansibility in existing large-scale water meter charging. The method comprises the following steps: constructing a water meter data column vector, calculating an original difference vector based on a current-period reading vector and a previous-period reading vector, and performing Boolean mask processing to obtain a meter reading water volume vector; actual water consumption accounting, total and score table allocation and allocated water amount calculation are achieved through vector operation; a billing water volume vector is obtained in combination with a preferential strategy, and an actual water fee is finally obtained through mixed water splitting, stepped billing matrix operation and water fee preferential adjustment. According to the method, vectorization and matrix operation are adopted to replace traditional line-by-line calculation, so that the operation efficiency can be improved through parallel calculation, the vector algorithm is designed to adapt to complex water affair billing logic, the processing performance is effectively improved, efficient and large-scale billing is achieved, the intelligent water affair development requirement is met, and practicability and popularization value are achieved.

A method for preparing and applying an iron hydroxyl oxide-metal-organic framework heterostructure alkaline water electrolysis catalyst is disclosed, belonging to the technical field of electrochemical energy storage materials. The preparation method involves: firstly, anolysing iron foam under constant current; then dissolving 2,5-dihydroxyterephthalic acid and nickel nitrate hexahydrate in a mixed solvent of N,N-dimethylformamide / ethanol / deionized water; transferring the mixture to a reaction vessel, tilting the iron foam into the vessel, sealing and heating the reaction, and then naturally cooling to room temperature; removing the iron foam, rinsing it with deionized water and ethanol (both sides), and finally vacuum drying. This method is simple and reproducible, requiring no cumbersome high-temperature pyrolysis or etching processes, and is suitable for large-scale preparation. In a standard three-electrode system, the prepared electrocatalyst is directly used as the working electrode in a 1 M KOH electrolyte for electrocatalytic reaction; the electrocatalyst exhibits excellent water splitting activity and cycling stability at high current densities.