95results about How to "High reducing activity" patented technology

The invention discloses a silver plating copper powder, a chemical plating liquid and a method of chemical plating; wherein, the silver coating ratio of the silver plating copper powder is 10 to 95%; the silver plating layer comprises 0.5 to 1.2wt% rare-earth metal cerium and / or lanthanum and / or yttrium; the chemical plating liquid comprises three independent components of silver nitrate water solution, formaldehyde ethanol solution and rare-earth nitrate water solution. The method of chemical plating is characterized in that (1) the copper powder is washed and is processed by ultrasonic sensitization and ultrasonic activation in sequence, and (2) the three components of the chemical plating liquid are added in sequence and the ultrasonic chemical plating is processed. The method of chemical plating has the advantages of utilizing the modification effect of rare-earth, raising the stability of plating liquid, the catalytic activity of copper powder surface and the reduction activity of silver ion, adjusting the silver coating ratio from 10% to 95% according to different demands, and even distribution, smooth surface and high conductivity and oxidation resistance of silver plating layer.

The invention relates to the speeding up degradation of organic pollutant in the soil, which uses strong reduction feature of metal nulvalent, synthetic metal oxidation and hydro oxidation, effectively reducing organochlorine insecticide and other contaminating pollutant, improving the biological degradation feature of organic pollutant. The above pollutant can be further degraded with the participation of organic acid. It can effectively realize the original position restoring of contaminated soil, particularly for the control and restoring of heavy polluted soil.

A catalyst of removing the NOx, residual organic substance and CO from the oxygen-enriched tail gas from engine contains the porous inorganic carrier, silver, noble metal chosen from Au, Pt, Pd, Ph, Ir and Ru, and other metal chosen from Fe, Cu, Ti, Zr, Ba, Sn, W, Zn, Mo, Ce, Cs, La and Ca.

The invention provides a 7 Beta-Hydroxysteroid dehydrogenase mutant, a coding sequence, a recombinant expression vector, a genetically engineered bacterium and an application thereof. Mutation is carried out on the 7Beta-hydoxy alcohol dehydrogenase from Collins aerogenes, and the reductive activity and the ratio of reducing and oxidizing activity of the obtained mutant Ca7Beta-2 are respectivelyincreased by 7.6 times and 4 times; when incubated in 100mM UDCA for 1 hour, the activity is decreased by 8.4%; at 30 DEG C and Ph 8.0, UDCA and T-UDCA are catalyzed and synthesized, and the conversion time is shortened from 24 hours to 2 hours, and the molar conversion of the substrate 7-KLCA is 100%, and the molar conversion of the substrate T-7-KLCA is 99.5% and the 7Beta-HSDH after mutation greatly reduces the production cost, improves the production efficiency, and is more suitable for industrial application.

A method of removing nitrates from water by utilization of a zero-valent iron / oxidizing agent / zeolite synergetic system is provided. The zero-valent iron is common iron powder. The oxidizing agent is a common oxidizing agent used in water treatment. The zeolite is natural zeolite or artificial zeolite. The method is characterized in that: the oxidizing agent in the system oxidizes and strips a passivation layer formed on the surface of the zero-valent iron to allow electrons in the zero-valent iron to be transferred continuously to the outside, so that the zero-valent iron maintains high reduction activity to reduce the nitrates into ammonia nitrogen. Then efficient selective absorption of the zeolite to the ammonia nitrogen is utilized to remove the ammonia nitrogen in the water body. The method is environmental friendly, simple, feasible, low in cost, and capable of being efficiently used for treatment of waste water containing nitrates of industrial enterprises and nitrate restoration and removal for underground water.

The invention belongs to the field of electrochemistry and relates to an electro-catalysis oxygen reduction catalyst based on boron-nitrogen co-doped nano-diamond, and the nano-diamond contains 0-5% of nitrogen and 0-5% of boron. The boron-nitrogen co-doped nano-diamond disclosed by the invention can use B2H6, N2, H2 and CH4 to deposit for 6-20h for preparation through a plasma chemical vapor deposition method under the conditions that the temperature is 420-600 DEG C, the pressure is 4-8kPa, the volume fractions of N2 and CH4 are 0.5-2.5% and 0.8-3% respectively, and the concentration of B2H6 is 5000-25000ppm. The boron-nitrogen co-doped nano-diamond has the advantages of high electro-catalysis activity, good stability and the like against oxygen reduction reaction, is a non-metal oxygen reduction material with good performance and low cost, and can be widely applied to fuel cells, metal-air cells, corrosion resistance and biological sensing.

The invention relates to a catalyst, in particular to phosphorus-doped graphene oxygen reduction electro-catalyst and a preparation method and application thereof. The phosphorus-doped graphene oxygen reduction electro-catalyst contains oxidized graphene substrate and active phosphorus doped or attached to the surface and inside of the oxidized graphene substrate. The preparation method includes the steps of 1, preparing the oxidized graphene; 2, mixing the oxidized graphene with phosphorus-bearing precursor; 3, drying; 4, performing pyrolysis. The phosphorus-doped graphene oxygen reduction electro-catalyst is good oxygen reduction electro-catalyst, is high in catalytic activity and resistant to methanol poisoning and carbon monoxide poisoning, good in stability and capable of serving as electro-catalyst for fuel cells and metal-air cells and serving as electrode active material for electrochemical energy storage and conversion devices such as lithium ion cells, sodium ion cells, lithium-sulfur cells and supercapacitors, and is also applicable to the fields such as electrochemistry / biosensors.

The invention provides a copper-nitrogen co-doped carbon nanotube catalyst and a preparation method and application thereof. The preparation method comprises the following steps of: (1) adopting carbon nanotubes as a substrate, performing reflux in an acidic solution, performing washing with water until neutrality is achieved, and performing drying; (2) adding a copper salt solution and dispersantinto the carbon nanotube powder obtained in the step (1), performing stirring, and adding a pH adjusting agent until a neutral state is achieved during stirring; (3) performing ultrasonic dispersionon the suspension obtained in the step (2), then performing stirring, and carrying out drying; (4) calcining the dried powder in the step (3) successively in an inert gas atmosphere and a reducing gasatmosphere so as to obtain copper-doped carbon nanotubes; (5) transferring the copper-doped carbon nanotubes obtained in the step (4) to a hydrothermal reaction kettle, adding a nitrogen source, andperforming a reaction; and (6) washing the suspension obtained in the step (5) to neutral, and performing drying. The preparation method has low cost, and is simple and easy to control, and the catalyst has high reduction activity in an electrocatalytic process of CO2.

The invention belongs to the technical field of ecological remediation, and discloses a method for remediating chromium polluted soil by enabling super fine iron powder to cooperate with microorganisms. The method comprises the following step of: sufficiently mixing the super fine iron powder and mixed bacteria with the chromium polluted soil to culture, thereby completing remediation of chromiumpolluted soil, wherein the mixed bacteria comprise chromium reducing bacteria, iron reducing bacteria and sulphate reducing bacteria. According to the method disclosed by the invention, the characteristic of corroding and releasing H2, in a remediation process, of the super fine iron powder is sufficiently utilized, and the microorganisms which take H2 as an electron donor are induced to grow andbreed on the surface, so that the microorganisms obtain energy, high-valence-state high-toxicity hexavalent chromium is reduced to be low-valence-state low-toxicity trivalent chromium, and the low-valence-state low-toxicity trivalent chromium is converted into occurrence forms, which are difficult in bioavailability, such as an iron-manganese combined form, an organic combined form and a residualform from a water-soluble form, an exchangeable form and a carbonate combined form, and therefore, transfer ability and bioavailability, in the soil, of chromium are reduced.

The invention relates to a 'catalyst used for ammonia selective catalytic reduction of nitrogen oxides to nitrogen gas and a preparation method thereof', and belongs to the catalyst technical filed. The catalyst consists of V2O5-WO3 / TiO2 / BaO / gamma-Al2O3. The catalyst takes gamma-Al2O3 as a carrier, which increases specific surface area of the catalyst and lowers the catalyst carrier cost; BaO is added to protect the carrier against sulfation, reduce oxidization activity on sulfur dioxide and prolong service life of the catalyst; and titanium dioxide is highly dispersed on surface of the carrier, thus improving utilization rate of the titanium dioxide. The catalyst is characterized by low cost, high catalytic activity and very low activity to oxidize sulfur dioxide to sulfur trioxide.

The invention relates to a method for removing complex-state heavy metals from a magnetic iron-based material through reduction decomplexing. The method comprises the following steps: weighing ferrite, dissolving ferrite into water which does not contain dissolved oxygen, adding Fe3O4 nano-particles, gradually adding an anaerobic NaOH solution into the solution, and simultaneously stirring to react for 10-30 minutes, so as to obtain black green turbid liquid; regulating the pH value of wastewater containing heavy metals to be more than 5.0, and controlling oxidation reduction potential ORP of the wastewater to be less than 100mV in an nitrogen aeration manner; adding a Na2CO3 solution according to the primary concentration of CO3<2-> in the wastewater so as to regulate the concentration CO3<2-> in the wastewater to be more than 500mg / L; adding the black green turbid liquid according to the type and concentration of heavy metal ions in the wastewater, and slowly stirring to react for 30-60 minutes; after the reaction is finished, introducing the wastewater into a magnetic separator, carrying out solid-liquid separation so as to finish the treatment of the wastewater, and separating magnetic seeds for later use. The method has the advantages that the preparation method is simple, conditions are mild, the cost is low, the effluent quality is good, and the reaction flow is short.

The invention relates to an amino compound-supported composite denitration catalyst, and a preparation method and an application thereof. The catalyst is prepared from 50-90 wt% of a carrier, 5-25 wt% of metal oxide and 5-25 wt% of an amino compound. The method comprises the following steps: weighing the carrier and a metal inorganic salt precursor, impregnating the carrier in an aqueous solution of a metal inorganic salt through an isopyknic impregnation technology, stirring the obtained solution, drying the stirred solution, introducing nitrogen, calcining the dried solution, weighing and dissolving the amino compound, impregnating the obtained calcined solid sample in the aqueous solution of the amino compound, and standing and drying the obtained solution to obtain the composite denitration catalyst. A fixed bed reactor is filled with the prepared composite catalyst, and normal pressure smoke is introduced and is denitrated. The catalyst has the characteristics of good economic property, energy saving, environmental protection, high denitration efficiency, and realization of repeated use of the recovered support amino compound, and is extremely suitable for the field of low temperature denitration of fixed sources.

The invention discloses a silver plating copper powder, a chemical plating liquid and a method of chemical plating; wherein, the silver coating ratio of the silver plating copper powder is 10 to 95%;the silver plating layer comprises 0.5 to 1.2wt% rare-earth metal cerium and / or lanthanum and / or yttrium; the chemical plating liquid comprises three independent components of silver nitrate water solution, formaldehyde ethanol solution and rare-earth nitrate water solution. The method of chemical plating is characterized in that (1) the copper powder is washed and is processed by ultrasonic sensitization and ultrasonic activation in sequence, and (2) the three components of the chemical plating liquid are added in sequence and the ultrasonic chemical plating is processed. The method of chemical plating has the advantages of utilizing the modification effect of rare-earth, raising the stability of plating liquid, the catalytic activity of copper powder surface and the reduction activity ofsilver ion, adjusting the silver coating ratio from 10% to 95% according to different demands, and even distribution, smooth surface and high conductivity and oxidation resistance of silver plating layer.

The invention belongs to the technical field of environmental engineering, and particularly relates to a preparation method and application of a polyhydroxy ferrous complex reduction system. The preparation method comprises the following steps: dropwisely adding an alkaline matter into an oxygen-free ferrite aqueous solution, stirring to react, and combining ferrous ions with all hydroxyl ions byregulating different ferrous ion / hydroxyl ion mol ratios and the type and content of anions, thereby forming a polyhydroxy ferrous complex (FHC); and adding a silver nitrate solution, a dispersant and a protective agent to form an Ag / FHC reduction system, thereby greatly enhancing the reducibility of the FHC. The Ag / FHC reduction system has the advantages of high reduction activity and high reaction rate, is convenient to add, and can be used for treating wastewater containing multiple nondegradable pollutants.

The invention discloses a method for manufacturing a fuel cell capable of synthesizing acetic acid simultaneously, which comprises the following main steps of: adding ethylene diamine tetraacetic acid (EDTA) serving as a complexing agent, formaldehyde serving as a reducing agent and solution of PdCl2 or PdCl2 and RuCl3 into a hydrothermal reactor, performing heating reaction, and cooling to obtain PdRu or Pd nanometer catalyst particles; mixing the PdRu or Pd nanometer catalyst particles and VulcanXC-72 to obtain carbon-loaded PdRu or Pd catalyst particles; mixing the carbon-loaded catalyst particles and polytetrafluoroethylene uniformly in ethanol, and performing ultrasonic dispersion to form paste; coating the paste on a stainless steel mesh uniformly, drying and pressurizing to obtain Pd and PdRu nanometer porous electrode plates; and assembling the fuel cell by using the Pd electrode plate as a cathode and the PdRu electrode plate as an anode, wherein electrolyte of an anode chamber and electrolyte of a cathode chamber are respectively sodium hydroxide solution of the ethanol and sulfuric acid solution of hydrogen peroxide and are separated by a positive ion membrane. The method is simple and has readily available materials, and the acetic acid can be synthesized while the fuel cell is used.

This invention relates to a method of preparing metal material using complex compounds. Electrolysis is carried out in the electrolyte under the protection of inert gas or air containing M3Y with composite compounds of M1M2X combine with the collector as a cathode and carbon, metal or conductive ceramic as anode. Controlling electrolysis voltage, so that M2 reduction reaction is the dominated reaction, and M1 and X is partly or all dissolved in the electrolyte as electrolysis going on. When M1 is H, M1 can be reduced to gas leaving away the cathode. At the end of electrolys, M2 alone or with part of the M1 and X-stay is left on the cathode, which is the corresponding metal. Since M1X part or all leave away cathode in this invention during electrolysis process, the reactivity and ability of cathode is enhanced, the reaction rate and the current efficiency are effectively improved and energy consumption is reduced.

The invention provides a method for preparing a cathode catalyst of a proton exchange membrane fuel cell, and relates to the preparation of a cathode catalyst of a Pt based unary proton exchange membrane fuel cell. The method is characterized in that: a carbon nanometer pipe is loaded with Pt to generate the catalyst; and by adjusting the initial concentration of a precursor, the ratio of a reducer to the precursor, the ratio of the reducer to OH- and the adding mode of the precursor, lowering the reduction temperature and the like, the Pt / CNTs cathode catalyst, of which the metallic particles are highly dispersed, nanometer-scaled and uniform in size, is prepared. In the method, the pretreatment on the metallic precursor and any surfactant or other protectants are unnecessary, and the catalyst can be directly reduced at a low temperature, so that the reducing activity of the catalyst on oxygen is greatly improved, and the utilization rate of the catalyst is further improved; moreover, the preparation process is easily operated, and the prepared products can be used as the cathode catalyst and the anode catalyst of other fuel cells, and also can be applied in the fields of gas reforming, cracking of organic matters, treatment of pollutants and the like.

The invention discloses a catalyst for a diesel engine on the basis of a composite main catalyst and a hydrotalcite-derived oxide, wherein a perovskite composite oxide and a modified molecular sieve are adopted as main catalysts, CeO2-ZrO2 is adopted as a cocatalyst, a modified hydrotalcite-derived oxide and gamma-Al2O3 are adopted as basic materials of a coating, and cordierite honeycomb ceramicis adopted as a carrier. A preparation process comprises the following steps of: determination of the use amount of raw materials; preparation of the perovskite composite oxide, the modified molecularsieve and the modified hydrotalcite-derived oxide, and preparation and coating of coating slurry. The catalyst and the preparation process disclosed by the invention have the beneficial effects thatby cyclic change of lean / rich condition of the diesel engine, the catalyst can catalyze adsorbing-reducing purifying reaction of NOx in exhaust by high efficiency; the composite main catalyst replacesthe noble-metal main catalyst of the traditional LNT (Lean NOx Trap) catalyst, so that the cost of raw materials is reduced, and the sulfur resistance and the heat stability are improved; the modified hydrotalcite-derived oxide replaces Al2O3 and BaO in the traditional LNT catalyst, so that the NOx adsorbing capability of the catalyst is obviously improved.

The invention relates to a method for removing a pollutant in water by a palladium-catalyzed polyhydroxy ferrous-reduced method, which is characterized in that a palladium chloride solution is added in a polyhydroxy ferrous (FHC) system, a chemical deposition mode is used to form a Pd / FHC redox system, the reduction performance of FHC is increased, a sodium hydrosulphite solution and a cobaltous chloride solution are added, so that the activity state of ferroporphyrin in the system can be kept, the concerted catalysis effect of Pd and Co can be performed, and the capability of FHC for reducing and conversing the pollutant can be increased. Compared with the prior art, the method for removing pollutant in water is in favor of increasing the reduction activity of FHC, and the prepared FHC system particles are uniform and stable, the reduction performance of FHC can be performed, more pollutant can be reduced and conversed by FHC, and an application of the FHC in treatment of difficultly degraded waste water can be promoted.

The invention relates to ferroboron alloy electroless plating solution, ferroboron alloy plating material of the ferroboron alloy electroless plating solution and a method for preparation thereof. The electroless plating solution contains ferrous sulfate 15-30g, potassium sodium tartrate 70-90g, sodium hydroxide 25-40g, potassium borohydride 1-5g and rare earth compound 0.1-1.2g in distilled water each liter. The ferroboron alloy plating material is the ferroboron alloy plating material which contains rare earth elements, a plating layer contains the rare earth elements 0.8-1.6wt% and boron 0.9-1.4wt%, and the allowance is ferric, the method comprises following steps: hanging a copper substrate into the electroless plating solution whose temperature is 40-60DEG C after pickling, washing with water, drying, sensitizing with ultrasound and activating with the ultrasound, and using aluminum wires or aluminium sheets with high purity to couple with workpieces. The method of the invention utilizes pretreatment (sensitizing and activating with the ultrasound) and the modification effect of the rare earth elements to solve the stability problem of the electroless plating solution and to form a qualified electroless plating Fe-B-RE alloy plating layer, and the performance of the reproducibility of the alloy plating layer is good.

The invention relates to a method for preparing metal iron from copper slag, belongs to the technical field of comprehensive utilization of metallurgical resources and solves the problems of the priorart that the molten iron prepared from copper slag has relatively high content of Cu, S and As and cannot meet the using requirements. The method for preparing metal iron from copper slag comprises the following steps: (A), performing alkaline-process and vulcanizing separation of the copper slag to obtain a sulfonium phase and a slag phase, enriching copper and FeO in the sulfonium phase, and enriching As in the slag phase; (B), performing smelting reduction separation of the sulfonium phase to realize separation of iron and sulfonium phase to obtain molten iron of metal while keeping the copper in the sulfonium phase. According to the method provided by the invention, the prepared molten iron contains less than 0.1% of copper, less than 0.3% of sulfur and less than 0.03% of As and meetsthe requirements on the molten iron for steelmaking.

The invention provides a borohydride reduction stabilizing system and a method for reducing ester into alcohol. The borohydride reduction stabilizing system comprises a borohydride reducing agent anda stabilizer for stabilizing the borohydride reducing agent, wherein the borohydride reducing agent is sodium borohydride or potassium borohydride, and the stabilizer is an alkali metal salt of alcohol. On the basis of an existing sodium borohydride / potassium reducing agent, an alcohol alkali metal salt (such as sodium alcoholate or potassium alcoholate) is added, and then the sodium borohydride / potassium reducing agent can keep stable and is not decomposed under a heating condition, so that on one hand, reduction activity is maintained in a relatively high state and the situation of excessiveuse is reduced, and on the other hand, generation of hydrogen is reduced and the process risk is reduced.

The invention provides a strong-reducing-property visible light response photocatalyst with urea and ferric chloride as raw materials and a preparation method of the strong-reducing-property visible light response photocatalyst and belongs to the field of photocatalysis and environmental protection. The prepared strong-reducing-property visible light response photocatalyst is prepared by adopting prepared g-C3N4 as a carrier, adopting sodium borohydride as a reducing agent, and loading nano-iron to a g-C3N4 chip. The prepared catalyst can utilize active nano-iron for reducing heavy metal ions in water, sedimentation is further generated, meanwhile, g-C3N4 can be utilized for oxidizing organic pollutants in water under the illumination condition, and effective combined treatment on the heavy metal ions and the organic pollutants is achieved. The preparation method is simple, raw materials are easy to obtain, cost is low, water treatment efficiency is high, good economic benefits and environmental benefits are achieved, and the strong-reducing-property visible light response photocatalyst can be well put into large-scale production.

The invention provides a preparation method of a Bi4O5Br2 self-assembled hollow flower-like sphere, which comprises the following steps: by using ethylene glycol and ethanol as solvents, bismuth nitrate pentahydrate as a bismuth source and potassium bromide as a bromine source, keeping the reactants in a hydrothermal reaction kettle for a certain time at a certain temperature to obtain the Bi4O5Br2 self-assembled hollow flower-like sphere. According to the preparation method, the bismuth-rich Bi4O5Br2 hollow flower-like sphere with novel appearance is prepared by adjusting the ratio of reaction raw materials by utilizing a simple solvothermal method; the bismuth enrichment strategy improves the position of the bottom of the conduction band, so that Bi4O5Br2 has stronger reducing capacity,and meanwhile, due to the hybridization of Br 4p and O 2p, the energy band of Bi4O5Br2 is more discrete, thereby promoting charge transfer in the photocatalysis process. By means of the hollow structure, unique characteristics of large specific surface area, multiple active sites, enhanced light absorption and carrier separation efficiency and the like are realized in Bi4O5Br2; and due to the unique structure and composition characteristics of the hollow flower-like sphere Bi4O5Br2, the hollow flower-like sphere Bi4O5Br2 has higher photocatalytic CO2 reduction activity than BiOBr and solid Bi4O5Br2 under irradiation of sunlight.

The invention provides an indium phosphide-indium oxide p-n junction porous microsphere composite material as well as a preparation method and application thereof. The preparation method comprises thesteps: performing air oxidation on a corresponding In2S3 precursor through a simple hydrothermal reaction technology to synthesize nano-scale porous layered In2O3 microspheres, and performing partialphosphorization by taking sodium hypophosphite as a phosphorus source and adopting a gas-solid reaction to prepare the indium phosphide-indium oxide p-n junction porous microsphere composite material. The indium phosphide-indium oxide p-n junction porous microsphere composite material has more active sites and is stable in structure, the porous p-n junction can accelerate transfer and transmission of photo-generated carriers, and the indium phosphide-indium oxide p-n junction porous microsphere composite material has obvious advantages in photocatalytic carbon dioxide reduction.

The invention discloses a preparation method of polyethylene glycol repaired graphene reinforced aluminum-based composite material, and relates to the preparation method of graphene reinforced aluminum-based composite material. The preparation method aims to solve a problem that grinding aid is residual in an aluminum alloy matrix, and realize self-repairing of the graphene. The preparation methodcomprises the step 1 of weighing the graphene, the polyethylene glycol and aluminum metal powder; the step 2 of putting the material obtained in the step 1 into a ball milling tank for ball milling;the step 3 of cold pressing; and the step 4 of preparing the composite material after the cold pressing. The grinding aid, polyethylene glycol is subjected to thermal decomposition to generate activeC atoms, and the C atoms can adsorb on the pits of the graphene, so that integrity of the graphene structure is greatly improved, good interface connection is formed, and overall performance of the material is greatly improved; the polyethylene glycol is beneficial to flake formation of the aluminum metal powder, so that a problem of high dispersion difficulty of the single-layer or few-layer graphene in the aluminum-based composite material is solved, and cold welding between the aluminum metal powders is reduced; polyethylene glycol is easy to remove, and the prepared few-layer graphene reinforced aluminum-based composite material is excellent in comprehensive performance. The method is suitable for preparing the graphene reinforced aluminum-based composite material.

Disclosed is a method for preparation of a photocatalyzer of high catalytic reduction activity, belonging to the art of photocatalysis. In order to decompose effectively the persistence contaminant to the environment such as the perfluorine compounds, the invention discloses a method for preparation of a photocatalyzer: firstly, pretreating the supported base material by deoiling, coating on the surface with a even Cu buffer layer of thicken of more than 5 nano, then, preparing Ni even buffer layer, and the supported substrate material being prepared. At last, preparing TiO2 precursor film on the supported substrate material, and burning by at least 20min in heat treatment device in a random temperature among 300- 600Deg. C, then the supported TiO2- CuO- NiO photocatalyzer of reducing power being prepared. The photocatalyzer prepared with said technique is characterized in that: the reducing activity is high, it is easy to separate and reclaim, the technique is simple, and it is totally suit for batch production.

The invention discloses a preparation method of modified nano-iron and application of the modified nano-iron in antibiotic drug manufacture wastewater treatment. The modified nano-ion is prepared through a reaction solution in a microemulsion state by adopting a liquid phase reduction method. The preparation method comprises the following steps that a surface modifier is added in an ethanol water solution of ferrous salt under the nitrogen condition, and the solutions are stirred and mixed to be uniform; a prepared aqueous alkaline solution of borohydride is dropwise added into the ethanol water solution of the ferrous salt, and after dropwise adding is completed, reacting is continuously performed for 20-30 min to generate a black precipitate; the black precipitate is filtered, washed, centrifuged, separated and dried to obtain the modified nano-iron. The preparation cost of the modified nano-iron is low and lower than that of commercial nano-iron, and the operation procedure is simple; the prepared modified nano-iron is large in specific surface area, uniform in particle size, good in dispersion and high in reduction activity and can quickly and efficiently degrade pollution when the modified nano-iron is applied to antibiotic drug manufacture wastewater treatment.

The invention provides a method for electrochemical reduction treatment of chloramphenicol. The method comprises the following steps: S1) preparation of a sulfur-doped oxygen-vacancy-containing molybdenum trioxide material: carrying out high-pressure reaction in an ethanol solvent by using molybdenum powder as a raw material and hydrogen peroxide as an oxidant to synthesize a lamellar oxygen-vacancy-containing molybdenum trioxide material, mixing sulfur powder serving as a sulfur source with the lamellar oxygen-vacancy-containing molybdenum trioxide material, and carrying out high-temperature vapor deposition to obtain S-Mo-O<3-x>; S2) uniformly loading S-Mo-O<3-x> on the surface of carbon paper to obtain a sulfur-doped oxygen-vacancy-containing molybdenum trioxide electrode; and S3) with the sulfur-doped oxygen vacancy-containing molybdenum trioxide electrode as a cathode, carrying out an electrochemical dechlorination reaction in a chloramphenicol-containing electrolyte. The sulfur-doped oxygen-vacancy-containing molybdenum trioxide material is obtained by introducing oxygen vacancy and the sulfur element, so the effects of dechlorination and detoxification are achieved in a short time, and the material is applicable to a wide pH range.

The invention relates to the technical field of catalysts, and discloses a preparation method and application of a NiFe-LDH catalyst for reducing nitrate to ammonia, wherein the preparation method comprises the following steps: dissolving nickel nitrate hexahydrate and alkali in a mixed solution of water and an organic solvent, stirring, adding ferric trichloride hydrate, continuously stirring, and carrying out a hydrothermal reaction; and after the reaction is finished, sequentially washing and drying to obtain the NiFe-LDH catalyst. The NiFe-LDH catalyst comprises a Ni(OH)2 nanosheet loaded with nano iron; the Ni(OH)2 nanosheet loaded with the nano iron forms a nano-layer structure. According to the invention, synergistic active sites composed of transition metal and oxyphilic metal hydroxides are utilized to improve the reaction efficiency of reducing nitrate into ammonia, and the reduction activity and the reaction selectivity are improved; and the NiFe-LDH catalyst can also be used as a bifunctional catalyst for a cathode and an anode at the same time.