155 results about "Chemical reduction" patented technology

The invention discloses a preparation method of a high-elasticity low-thermal-impedance graphene thermal interface material, which comprises the following steps: vertically dripping graphene oxide slurry on a substrate to form a graphene oxide gel array with a pre-oriented structure, and finally depositing the graphene oxide slurry on the surface to obtain the high-elasticity low-thermal-impedance graphene thermal interface material. And drying to obtain a graphene oxide film with certain vertical orientation inside, and carrying out chemical reduction foaming and high-temperature graphitization to obtain the thermal interface material. In the foaming process, oxygen-containing functional groups on the surface of the graphene oxide are converted into gas, graphene sheets are expanded, physical crosslinking is formed at the edge lap joint positions of the graphene sheets due to the pi-pi conjugation effect, and a quadrilateral-like structure is formed. Compared with a horizontally formed graphene film, the material has the advantages that the proportion of the internal graphene sheets arranged along the vertical direction is higher, the horizontal heat conduction capability is improved, better compression resilience is provided, the thermal impedance is reduced, and the material has wide application potential in the field of thermal interface materials.

The invention discloses a preparation method of a transition metal phosphide catalyst anchored by using a carbon-based material as a carrier and application of the transition metal phosphide catalyst in the field of formic acid hydrogen production, and belongs to the technical field of formic acid hydrogen production catalysis. Transition metal phosphide is anchored on a carbon-based material carrier in situ by adopting a chemical reduction method to obtain a precursor, and the precursor is roasted and pickled in a nitrogen atmosphere to obtain the novel carbon-based material loaded transition metal phosphide catalyst. The catalyst has the advantages of simple preparation method, high catalytic efficiency, cheap non-noble metal raw materials and the like, shows the formic acid conversion rate of 100% and the hydrogen selectivity of 99% or above in the catalytic gas-phase formic acid hydrogen production reaction, and also has good catalytic stability.

The application discloses a copper-bismuth bimetallic catalyst and a preparation method and application thereof. The copper-bismuth bimetallic catalyst comprises a copper substrate and copper-bismuth nanowires grown on the copper substrate, the copper-bismuth nanowires comprise copper nanowires and a metal bismuth layer loaded on the copper nanowires, and the mass fraction of bismuth in the copper-bismuth nanowires is 40% to 60%. The preparation method of the catalyst comprises the following steps: after in-situ growth of copper hydroxide nanowires on the copper substrate, the copper-bismuth bimetallic catalyst is prepared through heat treatment, electrochemical reduction treatment and bismuth deposition. Meanwhile, the copper-bismuth bimetallic catalyst can not only make full use of the copper and bismuth bimetallic effect, effectively improve the activity, stability and selectivity of electrocatalytic reduction of carbon dioxide, but also has the advantages of simple and controllable preparation, wide application potential window and wide application environment.

The invention discloses a carbon-deficient wastewater nitrate removal method based on water flow power, and belongs to the technical field of water treatment and environment restoration. According to the method, NO3-containing wastewater flows through a porous medium reactor at a certain flow speed, and contact between water flow and the surface of a filling material is utilized; the method comprises the following steps: by taking NO3 as a raw material, separating and inducing a contact electric effect, generating hydrogen free radicals with strong reducibility in situ, and realizing efficient non-biological reduction by utilizing a chemical reaction of the hydrogen free radicals and NO3 under the condition of not depending on an external carbon source or a chemical reducing agent. The method is mild in reaction condition, can be operated at normal temperature and normal pressure, has the advantages of simplicity and convenience in operation, low cost, no secondary pollution, wide medium source, reusability and the like, and is particularly suitable for NO3 pollution treatment in underground water, agricultural drainage and other carbon source lacking scenes.

This invention belongs to the field of SERS detection technology and relates to the application of an Ag / Bi4O5Br2 / Ni-Fe double hydroxide composite SERS substrate in the detection of CV in wastewater. First, a Bi4O5Br2 / Ni-Fe double hydroxide is prepared, and silver nanoparticles are loaded onto its surface using a liquid-phase chemical reduction method. This material combines the LSPR effect of silver nanoparticles with the interfacial coupling and multiple active sites of the Ni-Fe double hydroxide, enabling the regulation of interfacial charge transfer and enhancing molecular adsorption. Utilizing the excellent adsorption and enrichment properties of Bi4O5Br2, a highly efficient charge transport system is synergistically constructed from multiple components, improving the SERS chemical enhancement effect and amplifying the CV Raman signal. This invention overcomes the shortcomings of weak signals and insufficient stability of single substrates, achieving sensitive detection of trace CV in water. The substrate preparation process is simple, environmentally friendly, and highly practical, showing broad application prospects in the field of trace CV analysis in aquatic environments.

This invention provides a composite electrode for the comprehensive recovery of valuable metals, its preparation method, and its application. The composite electrode comprises a positive electrode active layer and a modified matrix layer. The modified matrix layer includes a tubular solid electrolyte body and a modified material layer disposed on the surface of the tubular solid electrolyte body; the modified material layer comprises a conductive polymer. The electrochemical lithium extraction combined with chemical reduction leaching of nickel, cobalt, and manganese using this composite electrode not only achieves high-efficiency recovery of valuable metals such as lithium, nickel, cobalt, and manganese, but also significantly reduces wastewater treatment costs and environmental risks.

This invention belongs to the field of composite material preparation technology, and provides an antibacterial activated carbon-silver ion composite photocatalyst and its preparation method. First, a nitrogen-doped titanium dioxide composite carbon dot core material is prepared using a hydrothermal method and high-temperature calcination, with titanium source, nitrogen source, and self-made carbon dots as raw materials. The core material is then surface-modified using a mercaptosilane coupling agent, and nano-silver is loaded in situ onto its surface via chemical reduction to obtain a multifunctional nanopowder. Simultaneously, activated carbon undergoes surface oxidation and amination treatment, and is grafted with the active ester polyethylene glycol maleimide, thereby constructing specific reaction sites on the activated carbon surface. Finally, the multifunctional nanopowder is covalently bonded to the activated carbon carrier surface using the Michael addition reaction between maleimide and mercapto groups. The resulting composite powder is then mixed with a dispersion medium and functional additives to obtain the antibacterial activated carbon-silver ion composite photocatalyst.

The invention discloses a chromium-containing wastewater treatment and recovery treatment line and a recovery treatment method thereof. The ion exchange system is used for carrying out ion exchange adsorption on the hexavalent wastewater; the alkali washing system is used for outputting alkali liquor to the ion exchange system; the washing system is used for outputting washing water to the ion exchange system; the pickling system is used for outputting acid liquor to the ion exchange system; the chromium recovery treatment branch line is used for receiving the hexavalent wastewater of the ion exchange system, mixing the hexavalent wastewater with sulfur powder and alkali liquor to prepare chromium hydroxide, then carrying out filter pressing on the chromium hydroxide, outputting a chromium hydroxide filter cake to the recovery calcination treatment line, and outputting a press filtrate to the press filtrate recovery branch line; the press filtrate recovery branch line is used for recovering sodium thiosulfate from the press filtrate; and the recycling and calcining treatment line is used for calcining the chromium hydroxide filter cake into Cr2O3. According to the scheme, the purposes of micro discharge and even zero discharge of the chromium-containing wastewater are achieved, and the problem that a large amount of chromium-containing hazardous waste sludge is generated by depending on a chemical reduction-precipitation method in traditional chromium-containing wastewater treatment is solved.

This invention discloses a method for preparing and applying a sodium borohydride-modified self-supporting anode for AEM water electrolyzers. Firstly, an amorphous ternary metal hydroxyl oxide precursor is grown in situ on a nickel substrate via room temperature liquid phase deposition. The process involves the presence of Co in solution. 2+ Fe 3+ Ni ions are introduced through slight corrosion of the nickel foam matrix. 2+ The ions, the three, and the OH- produced by hydrolysis ⁻ Co-deposition occurs under the influence of dissolved oxygen, leading to the self-assembly of amorphous nanosheet structures on the substrate surface. Subsequently, a mild chemical reduction treatment with sodium borohydride solution is used to obtain a structurally stable and high-performance self-supporting electrode. The method described in this embodiment is mild, simple, low-cost, and has good versatility.

The application is a kind of continuous preparation method and application of core-shell type reduced Cu-based catalyst. The method uses membrane dispersion micro-reactor technology, adopts liquid phase chemical reduction method with potassium borohydride-hydrazine hydrate as double reducing agent, continuously prepares reduced Cu-based nanoscale catalyst, does not need high temperature calcination and hydrogen reduction, can be directly used as active catalyst for catalytic reaction, and realizes green and efficient preparation. The catalyst prepared by the application is used in the reaction of preparing N-butyl-2,2,6,6-tetramethyl-4-piperidinamine from 2,2,6,6-tetramethyl-4-piperidinone and n-butylamine through reductive amination, and excellent catalytic activity and stability are shown.

This invention belongs to the field of photoelectric active materials and photoelectric sensing analysis technology, specifically relating to a Z-type heterojunction composite material, its preparation method, and its application. The composite material uses Ti-MOF as a precursor, annealing to obtain carboxyl-functionalized p-type 2DTiO2@C nanocakes. Chemical reduction forms AuNPs in situ on the surface of the 2DTiO2@C nanocakes, obtaining p-type 2DTiO2@C / Au nanocakes. Amino-modified p-type 3D peony-shaped BiOI is added to the p-type 2DTiO2@C / Au nanocakes, and electrostatic interaction yields the 2DTiO2@C / Au / 3DBiOI Z-type heterojunction composite material. This invention uses a metal-organic framework template-assisted calcination method, chemical reduction, and electrostatic interaction to design and prepare the Z-type heterojunction composite material, improving photoelectric activity and achieving rapid, highly sensitive, accurate, and reliable detection of hexavalent chromium ions.

The disclosure relates to a catalyst suitable for electrochemical reduction reactions of one or more carbon oxides, comprising a nitride-doped multi-metallic material comprising a primary metal being copper and one or more secondary metals selected from silver, gold, platinum, palladium, ruthenium, iridium, osmium, and any mixture thereof, wherein the nitride-doped multi-metallic material comprises, as determined by XRD, copper, copper nitride and copper-Me alloy wherein Me is one of the secondary metals and to a gas diffusion electrode suitable for electrolysis of one or more carbon oxides comprising such a catalyst.

The invention discloses a preparation method and application of a cerium-doped CoTeO3 nano-cluster catalyst, and belongs to the technical field of chemical energy materials. The preparation process comprises the following steps: firstly preparing a metal salt solution and a NaHTe solution, dropwise adding the NaHTe solution into the metal salt solution, stirring, centrifuging, cleaning and drying to obtain the cerium-doped CoTeO3 nano-cluster catalyst. The cerium-doped CoTeO3 nano-cluster catalyst prepared by the invention is constructed by a chemical reduction method, the conductivity of the catalyst is remarkably enhanced by introducing transition metal telluride, and the electronic structure of active sites is further optimized by doping rare earth cerium. In an electrocatalytic oxygen evolution reaction (OER), the catalyst breaks through the energy barrier limitation of a catalytic reaction intermediate by introducing a lattice oxygen oxidation mechanism (LOM), shows excellent catalytic activity and stability, and shows a good industrial application prospect.

The invention discloses preparation and application of a multi-site copper-based nanocrystal loaded noble metal monatomic catalyst, which comprises the following steps: dispersing copper-based precursors such as copper, copper oxide, cuprous oxide, copper sulfide and the like in cyclohexane to obtain a precursor dispersion liquid, stirring and heating to 150-300 DEG C, injecting a noble metal salt solution, reacting for 20-60 minutes, cleaning, and drying to obtain the multi-site copper-based nanocrystal loaded noble metal monatomic catalyst. The multi-site copper-based nanocrystal loaded noble metal monatomic catalyst dispersed in cyclohexane is obtained, noble metal is loaded on copper-based nanocrystals in a monatomic form, and the catalyst has relatively high electro-catalytic activity and ethylene selectivity and can be used for preparing hydrocarbon products through electrochemical reduction of carbon dioxide.

The invention provides a precious metal platinum-doped nano zinc oxide photocatalyst, a preparation method and application, and relates to the technical field of catalyst synthesis. The method specifically comprises the following steps: pretreating a natural biological material with a hierarchical porous structure as a soft template, and freeze-drying to obtain a Zn < 2 + > supported biological template; placing the template in a mixed solvent, performing microwave hydrothermal synthesis to obtain a ZnO (at) biological template, and performing centrifugal washing; preparing a doping solution containing noble metal ions, dissolving the ZnO (at) biological template in the doping solution containing noble metal ions, and irradiating under ultraviolet light; calcining in an air atmosphere, and then immersing a product into a citric acid solution to obtain the catalyst. By combining a natural biological template with microwave-assisted hydrothermal and in-situ photochemical reduction technologies, uniform doping of ultralow noble metals (Pt, Pd, Au and the like) in a ZnO hierarchical porous structure is realized, and material morphology regulation and control and active site construction are synchronously completed.

The invention provides a metallurgical furnace for multi-stage smelting and dilution of copper-nickel sulfide ore, and belongs to the technical field of non-ferrous metal pyrometallurgy equipment. The device is provided with a first-stage space smelting area, a second-stage molten pool smelting area, a third-stage molten pool reduction smelting area and a fourth-stage depletion smelting area which are communicated in sequence; a feeding nozzle and a spray gun are arranged at the top of the first-stage space smelting area to realize material pre-oxidation and impurity volatilization, and a side-blowing spray gun is arranged in the second-stage molten pool smelting area to finish deep smelting and slag-matte separation; a third-stage molten pool reduction smelting area is provided with a spray gun to create a reducing atmosphere, and impurities such as lead and zinc are selectively reduced and volatilized to be removed; a controllable polarity electrode and a sulfuration reducing agent feeding hole are arranged at the top of the fourth-stage depletion smelting area, so that electromagnetic stirring, chemical reduction sulfuration and the like are realized. Through multi-zone collaborative design and functional coupling, the problems that in the existing copper-nickel sulfide ore pyrogenic process, the smelting strength is improved, the adaptability to raw materials is poor, the slag dilution efficiency is low, and impurity valuable metal elements are difficult to enrich are solved.

The invention discloses an electrochemical catalyst for carbon dioxide reduction and a synthesis method and application thereof. The catalyst comprises a carrier and cuprous oxide, the cuprous oxide is in a spherical shape; the carrier is a titanium carbide MXene multilayer nanosheet. The catalyst is used in the electrochemical reduction reaction of carbon dioxide, and has the advantages of simple and non-toxic preparation process and high current density generated in the reaction process.

The invention provides an ex-situ chemical reduction stabilization remediation method for hexavalent chromium contaminated soil, which comprises the following steps: collecting soil from a contaminated land parcel, airing, crushing, screening and uniformly mixing to obtain pretreated contaminated soil; testing the content of hexavalent chromium in the polluted soil, then adding solid calcium polysulfide into the polluted soil according to the molar ratio of the solid calcium polysulfide to the hexavalent chromium of (12-16): 1, and uniformly mixing; and after uniform mixing, spraying water into the polluted soil according to 15-20% of the total solid mass, and carrying out static maintenance. According to the stable remediation method, the remediation target value (the hexavalent chromium in the soil is lower than 5.7 mg / kg) is achieved on the third day of maintenance, the remediation effect is continuous and good, and rebounding does not occur.

The application discloses activated carbon for reducing content of chlorate in water and a preparation method thereof, and belongs to the technical field of wastewater treatment. The application sequentially constructs a chlorinated glycidyl trimethyl ammonium cation layer for electrostatic adsorption of chlorate and a nano zero-valent iron functional layer for chemical reduction of the chlorate on the coconut shell activated carbon through bridging action and chemical grafting of polydopamine, forms a unique 'adsorption-degradation' integrated structure, greatly improves the treatment efficiency, ensures stability of functional components through chemical bonding, avoids secondary pollution, and has remarkable social, economic and environmental benefits.

The application discloses an X2H2 nano-catalyst rich in oxygen vacancies and a preparation method and application thereof in electrocatalytic reduction of carbon dioxide. The preparation method comprises the following steps: firstly, adding monohydrate citric acid into a solution containing copper salt and cerium salt, evaporating and concentrating the solution to form a sol, and then drying the gel to obtain a gel which is placed in a tube furnace for annealing, so as to obtain the X2H2 nano-catalyst rich in oxygen vacancies. The catalyst can be applied to electrocatalytic reduction of carbon dioxide to generate high-carbon products. The application has the characteristics of simple preparation operation, low cost and excellent performance (the selectivity is as high as 100%) in electrochemical reduction of carbon dioxide to ethylene and ethanol.

The invention discloses a foam metal substrate photo-thermal catalyst and a preparation method and application thereof.The preparation method comprises the steps that a foam metal substrate is subjected to low-temperature etching, and hydroxide nanowires are formed on the surface of the substrate; immersing the etched substrate into a mixed solution formed by an alkaline pH reagent, a reducing agent and an antioxidant to carry out wet chemical reduction reaction, and converting the substrate into vacancy-rich oxide nanowires; spraying a salt solution containing loaded metal ions on the surface of the substrate subjected to the wet chemical reduction reaction, and then carrying out heat treatment, so that a metal-loaded seed crystal is deposited on the surface of the substrate containing the vacancy-rich oxide nanowire; and immersing the substrate subjected to heat treatment into a salt solution containing loaded metal ions, adding a crystal growth regulator, and carrying out hydrothermal reaction to obtain the foam metal substrate photo-thermal catalyst. By introducing controllable strategies such as low-temperature etching, mild wet chemistry and normal-pressure growth, the process conditions are mild, and uniform, controllable and large-scale preparation of the large-area photo-thermal catalyst is successfully realized.

The application discloses an oxygen-enriched vacancy CeOx@Cu catalyst, a preparation method thereof and application of the catalyst in nitrate reduction, and belongs to the technical field of electrochemical catalytic materials and preparation thereof. The application solves the problems of slow kinetics of conversion of nitrite into ammonia and insufficient supply of active hydrogen species in the existing electrochemical reduction process of nitrate in water. In the application, CeO2 nanoparticles are uniformly loaded on a copper substrate by an electrodeposition method, and a composite catalyst CeOx@Cu with high-density oxygen vacancies is formed through calcination treatment, overflow of oxygen vacancy-mediated *H from CeOx to the copper surface significantly accelerates the reduction kinetics of nitrate, and side reactions are inhibited, thereby excellent ammonia generation performance (404.08 mu mol h ‑1 cm ‑2 ) and high Faraday efficiency (FE reaches 94.6%) are exhibited, and nitrate in wastewater can be effectively converted into ammonia, and electric energy can be recovered.

The invention is applicable to the technical field of nano material preparation, and provides a preparation method and application of a Mn < 2 + >-MoS2-Ag surface enhanced Raman spectrum substrate, the method comprises the following steps: synthesizing a Mn < 2 + >-doped MoS2 nano material through a hydrothermal method, and loading Ag nano particles on the surface of the Mn < 2 + >-doped MoS2 nano material by using an ultrasonic-assisted chemical reduction method to obtain the Mn < 2 + >-MoS2-Ag surface enhanced Raman spectrum substrate. The substrate combines a chemical enhancement effect brought by Mn < 2 + > doping and an electromagnetic enhancement effect provided by Ag nanoparticles to form a synergistic enhancement system. When being applied to SERS (Surface Enhanced Raman Scattering) detection of trace ofloxacin in a water environment, the sensor shows excellent sensitivity and specificity, and the detection limit can reach 10 <-11 > M. The method is simple in preparation process and mild in condition, the prepared substrate is good in stability and remarkable in enhancement effect, and an effective tool is provided for rapid and high-sensitivity detection of antibiotic pollutants in the environment.

The invention relates to the technical field of all-vanadium redox flow batteries, and discloses a mixed acid-based electrolyte and a preparation method and application thereof.The preparation method at least comprises the following steps that a sulfuric acid-based vanadium electrolyte is prepared through a chemical reduction-electrolysis method, the sulfuric acid-based vanadium electrolyte is poured into a rotary container of a rotary evaporator, rotary evaporation operation is conducted, and the mixed acid-based electrolyte is obtained; adding a barium chloride solution into the sulfuric acid-based vanadium concentrated solution, fully stirring to obtain a sulfate acid-based vanadium crude solution, filtering the sulfate acid-based vanadium crude solution by using a microfiltration membrane to obtain a filtrate, namely the sulfate acid-based vanadium concentrated solution, adding deionized water into the sulfate acid-based vanadium concentrated solution, diluting the concentrated solution, and filtering to obtain the sulfate acid-based vanadium sulfate. The mixed acid group vanadium electrolyte has the advantages of being high in energy density, wide in use temperature range and good in vanadium stability, and the problems that the hydrochloric acid concentration is difficult to control accurately and the environment is polluted due to hydrochloric acid volatilization and chlorine evolution during electrolysis in a conventional method are solved.

The invention discloses a preparation method of a functionalized palladium quantum dot loaded bismuth ferrite nanorod piezoelectric catalytic hydrogen evolution material, and belongs to the technical field of new energy catalytic materials. According to the invention, a palladium quantum dot loaded bismuth ferrite nanorod (Pd-BFO) cocatalyst is constructed by a simple method of electrostatic spinning and chemical reduction. The material can be used as a mechanical energy and chemical energy conversion platform and is used for efficient piezoelectric catalytic hydrogen evolution reaction. Under ultrasonic irradiation, the strong piezoelectric response of bismuth ferrite can induce ferroelectric polarization, and a built-in polarization field is formed to separate charges. Palladium quantum dots serve as a cocatalyst, transfer and enrichment of polarized charges can be promoted, the charge separation efficiency is improved, meanwhile, water adsorption and hydrogen desorption energy barriers are optimized, and therefore the piezoelectric catalytic hydrogen evolution activity is remarkably improved. The 0.5 wt% Pd-BFO material obtained through optimization can achieve the excellent hydrogen evolution rate of 4253.44 [mu] mol.g <-1 >. H <-1 >, and the performance of the Pd-BFO material is superior to that of most reported piezoelectric catalysts at present.

The application discloses a system and method for preparing CO gas by CO2 carbon-free deoxidation, a steelmaking induction furnace is transformed into a closed gas making furnace, CO2 or industrial tail gas containing high concentration CO2 is taken as raw gas and is introduced into an oxygen-saturated iron-based melt at 1600-1800 DEG C through a bottom blowing element, high concentration CO gas is prepared, FeO deoxidation product of CO2 is migrated to a slag phase and oxygen removal and iron reduction regeneration are realized through an external electric field mode, a new method for preparing CO by CO2 carbon-free deoxidation is constructed with the oxygen-saturated iron-based melt solute iron element as an oxygen transfer medium, meanwhile, the energy required by CO2 decomposition endothermic and molten slag electrochemical reduction can be generated through photovoltaic, wind, hydraulic or nuclear power generation devices, green electricity is used as an energy carrier to realize efficient quality-energy conversion of CO2 and CO under the condition of no additional carbon input, a carbon neutral cycle process of steel-chemical cogeneration coupling is opened up, and the application has good application and development prospect.

The application discloses solar positive silver powder with high dispersity and high tap density, which is prepared by decomposing silver iodide under blue light and inducing silver single element, has high dispersity and high tap density, and can well meet the fine line and low resistance requirements of solar positive electrodes. The application also discloses a manufacturing method of the solar positive silver powder, which comprises the following steps: preparing a system A solution, adding a solution, preparing a system B solution after blue light irradiation, mixing the system A solution and the system B solution, adding a flocculating agent to obtain silver powder precipitation, washing, drying and crushing the silver powder after solid-liquid separation, and obtaining the solar positive silver powder. Only the characteristics of silver iodide decomposition under light are used, silver single element is directly obtained through physical light irradiation, nucleation sites are provided for subsequent solar positive silver powder growth, and compared with chemical reduction, silver nucleus is obtained, so that the method is more simple and efficient.

The invention belongs to the field of detection application, and particularly relates to an Ag-coated SnS composite material, a preparation method of the Ag-coated SnS composite material and deep application of the Ag-coated SnS composite material in the field of dye molecule detection.The preparation method comprises the steps that firstly, tin trifluoromethanesulfonate and sodium thiosulfate serve as a tin source and a sulfur source respectively, and stannous sulfide is prepared through a hydrothermal method; then silver nitrate and sodium borohydride are utilized to attach silver to the surface of stannous sulfide through a chemical reduction method to obtain the Ag-coated SnS composite material, the obtained mixed material of the precious metal and the semiconductor utilizes the SERS technology to detect dye molecules in a trace mode, and the method has important significance in application to actual life.

The present invention provides an apparatus (10j) and method for separating different chemical species from each other when they are suspended or entrained in liquid metal as solid particles. The apparatus (10j) comprises a vessel (2) for containing liquid metal. The vessel (2) is continuously axially symmetric about a longitudinal axis (Z), and at least part of it tapers to an apex. The vessel (2) comprises an inlet (4) for the liquid metal having suspended or entrained therein, particles of a plurality of different chemical species of respectively different densities each in solid phase, an underflow outlet (5) for the liquid metal with a majority of particles of a first, denser one of the plurality of different chemical species suspended or entrained therein, and an overflow outlet (6) for the liquid metal with a majority of particles of a second, less dense one of the plurality of different chemical species suspended or entrained therein. The underflow outlet (5) is nearer to the apex of the vessel (2) than the overflow outlet (6). The apparatus (10j) also comprises a first electrode (12) coaxial with the longitudinal axis (Z) of the vessel (2), one or more second electrodes (14) spaced apart from the first electrode (12), and a source (17) of a magnetic field. The first and one or more second electrodes (12, 14) each have a magnetic susceptibility with an absolute value of less than 10-2 to avoid disturbing the magnetic field. They are arranged within the vessel (2) to be immersed in the liquid metal when the vessel (2) contains the same, thereby allowing an electrical current (I) to flow through the liquid metal between the first and one or more second electrodes (12, 14). The magnetic field has a major component which is substantially perpendicular to the flow of electrical current (I) through the liquid metal between the first and one or more second electrodes (12, 14). This generates a Lorentz force acting on the liquid metal, causing it to rotate around the longitudinal axis (Z) of the vessel (2). The method may be conducted using such an apparatus. The speed of rotation of the liquid metal is varied by altering the Lorentz force acting on it until the liquid metal forms a vortex inside the vessel (2), which separates the particles of the different chemical species from each other and directs them to a respective one of the underflow or overflow outlets according to their different densities. If the different chemical species also have different magnetic susceptibilities from each other, the magnetic field can act directly on the particles as well in different manners according to their different susceptibilities, thus enhancing their separation according to their different densities. For example, the liquid metal may comprise liquid sodium and the solid particles may comprise the insoluble reaction products from a redox reaction between the liquid sodium and an ore of iron and / or of manganese, in which the liquid sodium acts on the ore as a chemical reducing agent and excess unreacted liquid sodium acts as a transport medium for the insoluble reaction products.

The invention discloses a preparation method of a photoelectric catalytic membrane, and belongs to the technical field of collaborative treatment and directional conversion of flue gas pollution and carbon reduction and wastewater denitrification. The Cu / Cu2O / CF / PTFE catalytic membrane is prepared by adopting wet chemical reduction and electrostatic spinning methods, and is used for coupling CO2 in flue gas and NO3 <-> in wastewater and producing high-added-value chemicals. The catalytic membrane has the advantages of high dust aerosol filtering efficiency, low gas resistance and the like. According to the preparation method, the catalyst is prevented from falling off in a blending electrostatic spinning mode, the conductivity of the fiber membrane is enhanced by the carbon nano tubes, the carbonized catalytic membrane has good conductivity, and meanwhile, the Cu / Cu2O catalyst nano particles forming a Schottky heterogeneous interface in situ can effectively improve the photo-generated charge separation efficiency and promote coupling of CO2 and NO3 <-> to form urea. Due to the characteristics, the prepared catalytic membrane can realize efficient interception of dust aerosol, and also has efficient and stable synthesis of urea.