33results about How to "Avoid leaching" patented technology

The invention provides a stable multivalent metal surface doped ruthenium oxide catalyst, a preparation method thereof and application of the stable multivalent metal surface doped ruthenium oxide catalyst in a proton exchange membrane water electrolysis device, and belongs to the technical field of catalysts and preparation thereof. According to the prepared multivalent metal such as molybdenum, niobium, tungsten, tantalum and chromium doped ruthenium oxide catalyst, the active center electronic structure is effectively stabilized due to the flexible valence change of the multivalent metal in the oxygen evolution process, meanwhile, a surface layer can be constructed through surface doping, separation of the active center Ru and lattice oxygen is effectively inhibited, and the stability of the catalyst is improved. The prepared catalyst shows excellent catalytic activity and electrochemical stability in an acidic oxygen evolution reaction, has the advantages of low cost and good catalytic stability, and in addition, can stably operate under relatively high current density as a proton exchange membrane electrolyzed water anode catalyst.

The invention belongs to the field of planting nutrient soil, and particularly relates to a functional vegetable seedling substrate based on vegetable straw modification. The substrate is prepared from the following components in parts by weight: 6 to 7 parts of peat, 3 to 4 parts of tomato straw decomposed base material, 1.5 to 2 parts of perlite, 0.1 to 0.3 part of nutrient element loaded biochar, 0.1 to 0.2 part of mineral source potassium humate and 0.01 to 0.03 part of diatomite. According to the invention, a high-quality tomato straw decomposed base material is produced by adopting a rapid decomposition process, a tomato straw modified biochar base material is produced by adopting an anaerobic pyrolysis process, and through efficient compatibility of nutrient elements, mineral elements and the like, a new process and a new product of the functional vegetable seedling culture substrate based on tomato straw modification are produced.

The invention discloses a circulating type microwave cocoon cooking machine which is a key device for a reeling mill, the outer layer, the middle layer and the inner layer of cocoons are uniformly cooked at the same time in the cocoon cooking process most efficiently, and the defects of steam cocoon cooking, hot soup cocoon cooking, outer cooking and inner cooking can be overcome. The production efficiency is greatly improved, the quality of white steam filature silk is obviously improved, raw material consumption is obviously reduced, pupa acid leaching is effectively inhibited, and energy conservation and environmental protection are achieved.

The invention discloses an in-situ leaching liquid injection system and method for high-altitude ionic rare earth ore, and belongs to the field of rare earth hydrometallurgy. The system is composed of a liquid injection well pattern, a layered liquid injection device, a first liquid supply system, a second liquid supply system and a collection system. Exploring the thickness of an ore body weathering crust and vertical distribution of rare earth / impurities; the liquid injection hole is vertically divided into an upper layer liquid injection area (1 / 3-1 / 2 of the upper part) and a lower layer liquid injection area (1 / 2-2 / 3 of the lower part); a 1.0-1.4 wt% low-concentration diethylenetriamine-ammonium acetate composite leaching agent is injected into the upper layer, and co-leaching of impurities such as aluminum and iron is reduced; 1.5-2.5 wt% of high-concentration diethylenetriamine-ammonium acetate composite leaching agent is injected into the lower layer to ensure efficient leaching of rare earth; and rare earth-rich leaching liquid is collected. Compared with a traditional full-layer high-concentration process, the method has the advantages that the use amount of a leaching agent is reduced by 20-40% while the rare earth leaching rate is kept to be larger than or equal to 90%, the aluminum ion concentration of the leachate is reduced by 30-60%, the agent cost and the follow-up impurity removal load are remarkably reduced, and the method is particularly suitable for the high-altitude, low-temperature, low-air-pressure and thick-weathered crust environment.

The invention belongs to the technical field of metal separation, and particularly relates to a deep eutectic solvent, a preparation method and application thereof, and a method for selectively extracting lithium from a lithium battery positive electrode material. According to the deep eutectic solvent provided by the invention, nearly 100% selective leaching of lithium is realized in an extremely short time, and Ni, Co and Mn are almost not leached, so that the bottleneck that the rate and the selectivity are difficult to obtain at the same time in a traditional method is broken through; and the process conditions are mild and efficient, are far superior to the traditional process and are more suitable for practical industrial application, and the energy consumption and material consumption are remarkably reduced.

The invention discloses a preparation method of a pavement material based on an alkali-activated fly ash glass body, and relates to the technical field of road engineering materials and hazardous waste treatment. The method comprises the following steps: mixing fly ash with water, removing soluble ions, mixing with a nano material, carrying out melting treatment, and rapidly cooling in a magnetic field environment to obtain a fly ash glass body; performing heat treatment on the sintered red mud to obtain heat activated red mud; preparing a dry material comprising a gel material and aggregate, wherein the gel material is composed of a fly ash glass body and thermally activated red mud; mixing the alkali activator, the water reducer and the nanofiber, and uniformly stirring to obtain a homogeneous solution; and adding the homogeneous solution into the dry material, and uniformly mixing to obtain the pavement material slurry. According to the invention, deep dissolution and recombination of the fly ash vitreous body and the thermally activated red mud are promoted by using an alkali excitation technology, elements are promoted to be rearranged on a molecular level, an aluminosilicate network structure with high strength and durability is formed, heavy metals are effectively fixed, and reduction and recycling of the fly ash and the red mud are realized.

The invention discloses a preparation method of graphene nano copper yttrium oxide composite powder, and relates to the technical field of photocatalytic wastewater treatment and new materials. The preparation method comprises the following steps: adding absolute ethyl alcohol and starch into ultrapure water, uniformly stirring, adding graphene, performing ultrasonic dispersion, adding urea, a copper sulfate solution and a yttrium nitrate solution, and uniformly stirring to obtain a mixed solution; adding the mixed solution into a supercritical reaction device, setting a heating program, preserving heat, cooling to room temperature, taking out a reactant, centrifuging, filtering, washing and drying to obtain the graphene nano copper oxide composite powder. Nano copper oxide and nano yttrium oxide are uniformly intercalated and distributed in pores and the surface of redox graphene, the yttrium oxide increases the active surface area of copper oxide, excitons are effectively generated in a metal oxide system, the photocatalytic activity of the graphene nano copper oxide yttrium composite powder is remarkably improved, and the graphene nano copper oxide yttrium composite powder has a wide prospect in the aspect of treating organic wastewater.

The invention discloses a method for recovering valuable metals in copper smelting slow-cooling slag copper separation tailings, and belongs to the technical field of hydrometallurgy. According to the method, the oxygen pressure leaching condition is controlled, sulfuric acid and lignosulfonate are added into the copper smelting slow-cooling slag copper separation tailings slurry, Cu and Zn in the slow-cooling slag copper separation tailings are synergistically promoted to be transferred into the leaching solution from solid phases in the slag, leaching of impurities such as Fe and Si is inhibited, and therefore high-selectivity recovery of valuable elements Cu and Zn in the slow-cooling slag is achieved; and finally, Cu and Zn are separated through a step-by-step extraction method, and Fe is separated from leaching residues through a magnetic separation technology. The problem that valuable metal existing in a more stable form in the copper smelting slow-cooling slag copper separation tailing slurry is difficult to recover is solved.

The invention belongs to the field of mineral resource application, and particularly relates to an air pressure auxiliary alkaline leaching method for monazite ore alkaline decomposition slag, which comprises the following steps: obtaining the monazite ore alkaline decomposition slag containing U, Th and rare earth; the method comprises the following steps: dispersing monazite ore alkaline decomposition slag in a leaching agent solution containing a component A and a component B, and carrying out air pressure assisted leaching at 70-90 DEG C under the pressure of 0.6-1.5 Mpa; then carrying out solid-liquid separation to obtain a leaching solution enriched with U and Th and leaching residues enriched with rare earth; the component A is at least one of sodium carbonate, potassium carbonate and ammonium carbonate; the component B is at least one of sodium bicarbonate, potassium bicarbonate and ammonium bicarbonate. According to the method, a combined leaching agent of the component A and the component B is adopted for carrying out combined alkaline leaching treatment on the monazite alkaline decomposition slag, control over the temperature and the air pressure in the leaching stage is further matched, in this way, synergistic and adaptive physical and chemical characteristics of the monazite alkaline decomposition slag can be achieved, U and Th in the monazite alkaline decomposition slag can be effectively and synchronously leached out, and in addition, selective leaching of U / Th and rare earth can be achieved.

This invention discloses a cerium-doped calcium-based photothermal catalyst supported on carbon nanotubes and its application in the preparation of biodiesel, belonging to the field of catalysis technology. The photothermal catalyst is prepared by the following method: a calcium source and a cerium source are mixed and dissolved in an aqueous ethanol solution, then multi-walled carbon nanotubes are added and stirred to load the calcium and cerium sources onto the surface of the multi-walled carbon nanotubes. The mixture is then dried to remove the solvent; calcined under nitrogen protection; and after calcination, naturally cooled to obtain the cerium-doped calcium-based photothermal catalyst supported on carbon nanotubes. This invention utilizes the strong electronic interaction between cerium and calcium to regulate the structure of active sites, inhibiting the aggregation and loss of active components, while simultaneously enhancing the catalyst's broad-spectrum light absorption and photothermal conversion capabilities, thereby achieving efficient and green biodiesel production.

The invention discloses a stripping agent for a battery pole piece and a stripping method of the stripping agent, and belongs to the technical field of battery recycling. The stripping agents are phosphonic acid and derivatives thereof, the stripping liquid prepared from the stripping agents of phosphonic acid and derivatives thereof with specific structures is used for auxiliary stripping of battery pole pieces, soaking treatment is carried out on the battery pole pieces with uniform sizes obtained by crushing and grading, and then the mixture is screened to obtain aluminum foil and a positive electrode material. By utilizing the acidity and coordination of phosphonic acid and derivatives thereof, the positive electrode material is quickly stripped from the aluminum foil, and meanwhile, metal leaching is inhibited. The method can directly recover the high-purity aluminum foil and the positive electrode material, is beneficial to subsequent regeneration, and has the advantages of simple process, low cost, high recovery efficiency and the like.

The application discloses a solar photo-thermal foam for treating salt-containing organic wastewater and a preparation method thereof. The application solves the problems of poor desalination effect, low degradation ability for organic pollutants, especially volatile organic pollutants, and easy concentration of organic pollutants in the bottom liquid in the process of treating salt-containing organic wastewater by solar photo-thermal treatment. The application comprises the following steps: preparing a photo-thermal foam by loading a copper-cobalt binary metal catalyst on a nickel-based metal foam, and using the photo-thermal foam to treat water in a device for treating salt-containing organic wastewater by solar photo-thermal treatment. The porous foam substrate is used to construct a high-performance photo-thermal foam with a special morphology, and under the synergistic action of a multi-metal catalytic system, efficient desalination and catalytic persulfate degradation of organic pollutants in the bottom liquid and condensate are realized in the process of treating salt-containing organic wastewater by solar photo-thermal treatment, so that high-quality pure water is obtained. In addition, the photo-thermal foam catalyst is simple to recover and can effectively inhibit metal leaching toxicity, and has good repeated stability.

This invention discloses a solidification and stabilization agent and treatment method for sieved humic soil in landfills. The agent comprises: a cementing component, a heavy metal stabilizing component, an organic matter passivating component, a pore-regulating component, and a process conditioning component. The cementing component includes steel slag, fly ash, and sulfoaluminate cement; the heavy metal stabilizing component includes calcium dihydrogen phosphate and sodium sulfide; the organic matter passivating component includes potassium permanganate; the pore-regulating component includes desulfurized gypsum and an air-entraining agent; and the process conditioning component includes a polycarboxylate superplasticizer and a triethanolamine early-strength agent. This invention provides core strength through a synergistic cementing system of steel slag-fly ash-sulfoaluminate cement, combines a phosphate-sodium sulfide dual stabilization mechanism to fix heavy metals, uses potassium permanganate to oxidize and passivate humic acids, and introduces desulfurized gypsum and an air-entraining agent to regulate the pore structure. The agent of this invention can significantly improve the mechanical properties of the solidified body, reduce permeability, and effectively inhibit the leaching of heavy metals and organic pollutants.

The invention discloses a method for extracting white carbon black from shale vanadium extraction tailings. The method comprises the following steps: (1) crushing and screening the shale vanadium extraction tailings to obtain tailings powder; (2) uniformly mixing the tailing powder with a roasting additive, and then carrying out roasting treatment to obtain a roasted material; the roasting additive is prepared from alkali, CH3COONa and NaF; (3) leaching the roasted material, and carrying out solid-liquid separation to obtain a silicon-containing leachate; and (4) carrying out silicon precipitation, filtering, washing and drying treatment on the silicon-containing leachate to obtain the white carbon black. According to the method for extracting the white carbon black from the shale vanadium extraction tailings, the adopted roasting additives comprise the alkali, the CH3COONa and the NaF, and the alkali, the CH3COONa and the NaF have a synergistic effect, so that leaching of silicon dioxide in the shale vanadium extraction tailings can be promoted, leaching of impurities is reduced, the leaching rate of the silicon dioxide can be increased, and a high-dispersity and high-purity white carbon black product can be obtained.

This invention belongs to the field of agricultural planting technology and proposes a method for integrated drip irrigation and fertigation of corn using mulch-side planting. The method includes: employing a wide-narrow row planting method; laying mulch film above the narrow rows; pressing the edges of the mulch film into the soil and covering them with soil; sowing corn seeds 4-5 cm outside the edge of the mulch film exposed on the ground; and laying drip irrigation tape under the mulch film. Irrigation is controlled by monitoring the soil matrix potential at a depth of 20-25 cm below the drippers of the drip irrigation tape, initiating irrigation when the soil matrix potential is ≤-15 kPa. During irrigation, all phosphate fertilizer is applied as base fertilizer; a portion of nitrogen fertilizer is applied as base fertilizer, with the remainder applied in multiple top dressings; and all potassium fertilizer is applied as base fertilizer, or a portion is applied as base fertilizer, with the remainder applied in multiple top dressings. This method significantly improves the mulch film recycling rate while ensuring stable and high corn yields, achieving the goals of water conservation, emission reduction, and efficiency improvement in arid areas.

This invention relates to the field of membrane technology, specifically to a nitrogen-doped carbon nanofiber catalytic membrane loaded with monatomic iron, its preparation method, and its application. It includes the following steps: (1) dissolving polyacrylonitrile and ferric chloride hexahydrate in a solvent to obtain an electrospinning precursor solution; (2) electrospinning the electrospinning precursor solution to obtain a precursor fiber membrane; (3) calcining the precursor fiber membrane under a protective atmosphere to obtain a nitrogen-doped carbon nanofiber catalytic membrane loaded with monatomic iron. The nitrogen-doped carbon nanofiber catalytic membrane loaded with monatomic iron prepared by this invention achieves near-complete utilization of metal atoms in advanced oxidation processes, significantly improving pollutant degradation activity and reaction kinetics; this material also possesses excellent structural stability and recyclability, providing a new design concept and technical path for developing efficient and scalable water treatment catalytic materials.

This invention belongs to the field of wastewater oxidation treatment, specifically relating to a carbon nanotube-encapsulated alloy catalyst, its preparation method, and its application. To address the technical problems of low catalytic efficiency and secondary water pollution caused by the leaching of metal ions due to the use of transition metal ions in existing heterogeneous catalysts for organic wastewater treatment, this invention provides a carbon nanotube-encapsulated alloy catalyst. The catalyst is prepared by dissolving nickel and zinc salts in water, leaching the solution into a cyanamide compound powder, stirring, drying, calcining at 450–600°C, and then cooling to obtain a powder. The powder is then calcined at 700–1000°C under an inert atmosphere, acid-washed, and then washed with water and dried. The carbon nanotube-encapsulated alloy catalyst obtained by this method exhibits high catalytic activity against persulfate and shows significant removal effects for different pollutants in different water bodies.

The invention discloses a preparation method of a high-capacity grafted carbon capture spherical solid amine material, and the solid amine carbon capture material is prepared by taking macroporous crosslinked polystyrene containing active reaction groups as a raw material and reacting with polyethylene polyamine protected by CO2. In the gradient heating process, polyethylene polyamine protected by CO2 reacts with macroporous crosslinked polystyrene resin containing active reaction groups for grafting while being deprotected, so that an additional link reaction generated in the direct reaction process of the polyethylene polyamine and the polyethylene polyamine is avoided. The obtained solid amine carbon trapping material is granular, the amine loading capacity is obviously improved compared with that of a direct grafting method, polyethylene polyamine chains are more dispersed on the surfaces of pore channels, and thus the material has more excellent adsorption performance on carbon dioxide.

The utility model discloses a kind of cleaning devices of plastic board, including cleaning push subassembly, cleaning push subassembly includes the cleaning support frame of setting, the chute mouth of being opened in the frame of cleaning support frame, slide rail being inserted into chute mouth, L type push plate being fixed in the top surface of slide rail, first fixed plate being fixed in the bottom surface of L type push plate, second fixed plate being fixed in the bottom surface of cleaning support frame, first electric telescopic link connecting first fixed plate with second fixed plate;Cleaning assembly, cleaning assembly includes the first cleaning scraping strip of being through the frame of cleaning support frame, support column being fixed in the top end of cleaning support frame.The utility model is cooperated by the cleaning push subassembly and cleaning assembly of setting, forms the structure design without need to turn over, reaches when using, the two faces of plastic board are cleaned simultaneously, cleaning can be completed once, avoid the problem that the face that has been cleaned is caused pollution in turning over process, improve cleaning efficiency.

Provided is a positive electrode for a lithium-sulfur secondary battery comprising a positive electrode active material, an electrically conductive material, a binder, and a multivalent metal salt. The multivalent metal salt comprises a cation of a metal selected from a group consisting of metals having 3 to 6 of an effective nuclear charge of outermost electrons in the 3rd and 4th periods. The positive electrode for the lithium-sulfur secondary battery can improve the performance of the lithium-sulfur secondary battery by introducing a multivalent metal salt and thus effectively inhibiting the leaching of lithium polysulfide when applied to the battery while not significantly increasing the weight of the electrode and not significantly lowering the conductivity of the electrode.

The present invention provides a radioactive waste resin regenerative decontamination treatment device, comprising a radioactive waste resin transmission device, an H2SO4 elution chamber connected to the radioactive waste resin transmission device through a pipeline, a resin elution residual liquid separation chamber connected to the H2SO4 elution chamber through a pipeline, an H2SO4 residual liquid neutralization chamber connected to the resin elution residual liquid separation chamber through a pipeline, a waste liquid evaporation device connected to the H2SO4 residual liquid neutralization chamber through a pipeline, a cement solidification device connected to the waste liquid evaporation device through a pipeline, and a control room connected to the resin elution residual liquid separation chamber through a pipeline, wherein a radiation monitoring instrument and a three-way valve are sequentially arranged on the pipeline connecting the resin elution residual liquid separation chamber and the control room, and the three-way valve is connected to the H2SO4 elution chamber through a pipeline. The present invention provides a radioactive waste resin regenerative decontamination treatment method. The radioactive waste resin regenerative decontamination treatment device and treatment method provided by the present invention have simple structure, convenient operation, safety and reliability, and good treatment effect.

This invention discloses a method for preparing phenolic chemicals by hydrogenolysis of lignin catalyzed by a cobalt-based nitrogen-carbon composite material. Using organosoluble lignin as raw material, a cobalt-based nitrogen-carbon composite material as catalyst, and a mixed solvent of small organic molecule alcohol and formic acid, the reaction is carried out under an inert gas atmosphere of 0.5–3 MPa, maintaining a reaction temperature of 210–250 °C, and a reaction time of 2–6 h. This method catalyzes the depolymerization of lignin to obtain a series of p-hydroxyphenyl products, achieving high-value utilization of lignin. The lignin conversion rate of this invention is as high as 89.6%, the total yield of monophenolic products can reach 17.7%, of which the yield of p-hydroxyphenyl products reaches 9.0%, with a selectivity of 50.8%. The catalyst preparation process used in this invention is simple and can catalyze the hydrogenolysis of lignin by short-chain alcohols and carboxylic acid solvents under mild conditions to obtain high-value-added chemicals such as p-hydroxyphenyl products.

This invention discloses a slow-release water-soluble fertilizer and its preparation method, belonging to the field of water-soluble fertilizer technology. The slow-release water-soluble fertilizer includes: a mesoporous carrier, a surface functionalization modifier, macronutrient raw materials, micronutrient raw materials, a water-soluble dispersing agent, and a pH adjuster. The preparation method includes: preparing a mesoporous carrier, functionalizing the surface of the mesoporous carrier, and loading the nutrient raw materials into the mesoporous carrier to prepare the finished water-soluble fertilizer. This invention uses a modified mesoporous carrier and constructs an ion-gated slow-release system by grafting pH-responsive functional groups onto its surface. The fertilizer is completely water-soluble and leaves no residue. After entering the soil, the nutrient release rate is triggered according to the change in rhizosphere pH, solving the dual technical problems of rapid nutrient loss in conventional water-soluble fertilizers and poor water solubility in coated slow-release fertilizers, thus improving fertilizer utilization.

This invention discloses a method for preparing a peak-supported carbon nanocatalyst by metal-directed carbonization, comprising: Step 1: preparing hierarchical organic microspheres; mixing at least one aldehyde compound with an aprotic solvent to obtain solution I, mixing at least one amino compound with a protic solvent to obtain solution II, and mixing solution I and solution II to perform a condensation reaction to obtain hierarchical organic microspheres; Step 2: loading metal ions; dispersing the hierarchical organic microspheres prepared in step 1 in a solution containing metal ions, and loading the metal ions onto the hierarchical organic microspheres to obtain a metal ion-organic microsphere composite; Step 3: carbonization; subjecting the metal ion-organic microsphere composite prepared in step 2 to carbonization treatment to obtain a peak-supported carbon nanocatalyst. The catalyst prepared by this invention has the characteristics of highly accessible active sites and structural stability, exhibiting excellent anti-poisoning performance and catalytic activity.

This invention discloses a green production method for biodiesel. First, pretreated feedstock oil and methanol are preheated and then fed into a reactor loaded with a superhydrophobic polymer solid acid catalyst for esterification. After oil-water separation, the oil phase is then fed into a reactor loaded with a macroporous strong-base ion exchange resin for transesterification. The biodiesel product is collected by vacuum distillation. The biodiesel production method provided by this invention has strong feedstock adaptability, no wastewater discharge, and excessive energy consumption. Methanol can be recycled, resulting in high feedstock utilization and product quality. Furthermore, the catalyst is simple to prepare, the reaction rate is fast, and the active phase is not easily lost.

The invention relates to a non-noble metal-loaded nitrogen-doped mesoporous carbon catalyst for synthesizing gamma-valerolactone through hydrogenation of levulinic acid and a preparation method of the non-noble metal-loaded nitrogen-doped mesoporous carbon catalyst. The non-noble metal is selected from one of Co, Fe, Ni and Zr and is wrapped in a carbon layer in a nano-particle form. The preparation method comprises the following steps: pyrolyzing melamine to obtain a graphite-phase C3N4 carrier; mixing C3N4 with glucose and a metal nitrate aqueous solution, and performing low-temperature hydrothermal treatment; and carrying out carbon thermal reduction on the centrifugally separated solid in a nitrogen atmosphere to obtain the catalyst. The catalyst provided by the invention is simple in preparation process and high in yield, and gamma-valerolactone can be prepared by efficiently catalyzing levulinic acid hydrogenation under mild conditions. According to the method, hydrogen is used as a hydrogen source, levulinic acid, a solvent and a catalyst are put into a closed container, the reaction is performed for 3 hours at the temperature of 180 DEG C under the hydrogen pressure of less than 2 MPa, the complete conversion of levulinic acid can be realized, the yield of gamma-valerolactone is as high as 99.7%, no metal is separated out, and the conversion rate of levulinic acid is still kept above 90% after the catalyst centrifugally separated after the reaction is recycled for 10 times.

The invention discloses a preparation method of a dual-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on a strategy of partially filling oxygen vacancies with anions, and relates to a preparation method of an oxygen evolution reaction spinel oxide electrocatalyst. The technical problems that an existing pure spinel oxide is low in catalytic efficiency and unstable in structure are solved. The preparation method comprises the following steps: 1, preparing a self-supporting spinel oxide electrode material; 2, preparing a self-supporting oxygen vacancy enriched spinel oxide electrode material; 3, preparing a self-supporting oxygen vacancy part anion filling type catalyst; according to the invention, an oxygen vacancy-anion partial filling strategy is utilized to regulate and control the local structure and the electronic state of the spinel oxide. The overpotential of the prepared Co3O4-VO-S / NF catalyst in 1.0 M KOH at the current density of 50 mA cm <-2 > is as low as 301 mV, and the Co3O4-VO-S / NF catalyst can stably run for more than 120 hours and can be used in the field of hydrogen production by water electrolysis.

The invention belongs to the technical field of electrochemical sensing and nano materials, and particularly relates to a preparation method of an oxygen-bridged platinum-based diatomic catalyst and application of the oxygen-bridged platinum-based diatomic catalyst in detection of dopamine and hydrogen peroxide. A coordination-pyrolysis method is adopted, firstly, 2-hydroxy-5-methyl isophthalaldehyde, chloroplatinic acid and the like are used as raw materials to synthesize a precursor, then the precursor is subjected to pyrolysis treatment and then loaded on conductive carbon black, and finally the oxygen-bridged platinum-based diatomic catalyst (Pt2-N4O2 / CB) is prepared. When the catalyst is applied to an electrochemical working electrode, high-sensitivity and high-selectivity in-situ real-time detection on biomolecules such as dopamine (DA) and hydrogen peroxide (H2O2) can be realized, and meanwhile, the catalyst has excellent anti-interference capability and long-term stability, can be adapted to various electrode types, has good technical transformation potential, and can be widely applied to electrochemical working electrodes. The method has a wide application prospect in the fields of neuroscience research and biomedical diagnosis.

The application relates to the technical field of polymer materials and building material additives, in particular to a heavy metal complex type tailing filling water reducing agent based on biological enzyme catalysis and a preparation method thereof; the preparation method comprises the steps of monomer premixing, enzymatic oxidation coupling polymerization, termination and activation; the method constructs a homogeneous aqueous phase environment by adjusting the pH of a multi-monomer system through a buffer, continuously introduces oxygen-containing gas to maintain the oxidation reaction cycle, the core is to generate a polymer skeleton containing an aromatic ring C-C bond or a C-O-C aromatic ether bond by using biological enzyme catalysis, and a heavy metal stable chemical complex structure is constructed by introducing a nitrogen heteroaromatic compound; the application solves the technical problems that a traditional water reducing agent is easy to be out of control in a heavy metal environment and has no chemical anchoring capacity, uses enzymatic polymerization, space steric hindrance and chemical complexing to solve the synthesis obstacles of complex industrial wastewater and the heavy metal leaching risk, effectively inhibits secondary pollution and improves the compressive strength of the filling body.

The invention relates to silicon activated biochar and a preparation method thereof, and the preparation method comprises the following steps: S100: obtaining a raw material containing a silicon planting body, the silicon content of the raw material being 5% or above; s200, air-drying the raw materials obtained in the step S100, placing the air-dried raw materials in a carbonization furnace in an oxygen-free atmosphere, carbonizing the air-dried raw materials at 700 DEG C or below for 2-2.5 h, cooling the carbonized raw materials, and crushing and grinding the cooled raw materials to obtain carbonized raw materials; and S300, the C-Si mutual protection structure in the carbonized raw material obtained in the step S200 is destroyed through chemical modification or physical modification, silicon dissolution is promoted, silicon activated biochar is obtained, and the effective silicon content in the silicon activated biochar ranges from 100 mg / kg to 1000 mg / kg.