34results about How to "Achieving controllable equipment" patented technology

The invention belongs to the technical field of catalyst preparation, and particularly relates to a preparation method of a Fe-Ni bimetallic catalyst wrapped by a carbon nano tube and application of the Fe-Ni bimetallic catalyst in sewage treatment. The method is realized through the following steps: firstly, dissolving ferric salt, nickel salt and terephthalic acid in a solvent, performing heating reaction after violent stirring, cooling to room temperature, collecting obtained precipitates, performing centrifugal washing, and finally performing vacuum drying to obtain MIL-88B (Fe, Ni); the preparation method comprises the following steps: uniformly mixing MIL-88B (Fe, Ni) powder with melamine, and carrying out pyrolysis to obtain M-Fe-Ni; the bimetallic catalyst (M-Fe-Ni) wrapped by the carbon nano tube prepared by the preparation method disclosed by the invention can be used for degrading organic pollutants, and after being activated by PMS, the M-Fe-Ni shows obvious Fenton-like catalytic activity for degrading the organic pollutants such as sulfamethoxazole and the like. The degradation rate of the synthesized M-Fe-Ni catalyst can reach 99.9% in an extremely short time, and is higher than the degradation efficiency of a single metal catalyst (Fe3C / Fe-coated N-C-9). Besides, due to double reaction sites of the prepared M-Fe-Ni catalyst, the migration distance between active substances and organic pollutant molecules is greatly shortened, the catalytic performance of M-Fe-Ni is remarkably improved, and degradation of organic pollutants under the condition of no secondary metal pollution is facilitated. And a potential method is provided for efficient sewage treatment of the M-Fe-Ni / PMS system.

The invention relates to hollow silicon dioxide microspheres and a preparation method thereof.The preparation method comprises the steps that an aqueous solution of a polymer, azide salt, an initiator and an organic solvent are mixed to obtain an azide-modified polymer, and the azide-modified polymer is added into a polar solvent to obtain a solution of the azide-modified polymer; mixing alkynyl-containing silane, the azido-modified polymer solution and a click chemistry catalyst, and then adding an acid catalyst or a base catalyst to carry out hydrolytic condensation reaction, so as to obtain a core-shell structure precursor of the silicon dioxide coated polymer; and carrying out roasting treatment or solvent extraction treatment on the core-shell structure precursor to obtain the hollow silicon dioxide microspheres. The preparation method provided by the invention is simple in process, relatively low in cost and relatively high in efficiency, can effectively control the particle size, the wall thickness and the density of the prepared hollow silicon dioxide microspheres, and has a wide application prospect.

The preparation method comprises the following steps: dissolving PVDF (Polyvinylidene Fluoride) in acetone, adding a small amount of Tween 80, carrying out oil bath at 60 DEG C, and uniformly mixing until the solution is transparent, so as to prepare a polymer solvent system; and standing and defoaming the obtained solution, pouring into a mold, and naturally volatilizing by controlling the humidity to obtain the polymer porous membrane with the porous microsphere net structure. According to the method, phase separation is induced through solvent evaporation, and synchronous construction of micron holes and nanospheres of the PVDF porous membrane is achieved. Compared with a traditional phase separation membrane preparation technology, the method has the advantages that the pore size of the PVDF porous membrane can be greatly expanded, controllable preparation of micron / nano pores of the PVDF porous membrane is realized, and the prepared porous membrane has more excellent reflectivity and cooling performance.

This invention discloses a method for controllable preparation of nanoparticles using a multi-channel microreactor. The method utilizes a microchannel reactor to segment droplets and prepare quantitatively synthesized nanoparticles with controllable particle size. The invention employs capillary action to draw the reaction solution into the microchannel, segmenting one or more droplets (each droplet into 10-100 portions). By changing the width of the microchannel, controllable preparation of nanoparticles within a small range (±3 nm) can be achieved; by changing the length of the microchannel, controllable preparation of nanoparticles within a large range (±10-30 nm) can be achieved. Furthermore, the reactor structure of this invention is simple, enabling highly precise and quantitative synthesis of various nanoparticles. Compared to large-scale reactors, the miniaturization of the synthesis reaction in this invention effectively reduces energy waste and safety hazards, making it highly valuable for applications in safe chemical engineering, green chemical engineering, high-efficiency chemical engineering, microchemical engineering, and precise reaction monitoring.

The invention provides a wurtzite boron nitride / diamond composite material and a preparation method and application thereof, the composite material is composed of two phases of wurtzite boron nitride and diamond, and has a stacked sandwich microstructure, the sandwich microstructure comprises at least one first wurtzite boron nitride layer and at least one second wurtzite boron nitride layer, wherein the first wurtzite boron nitride layer is formed by wurtzite boron nitride; at least one second wurtzite boron nitride layer composed of wurtzite boron nitride; the composite material comprises a first wurtzite boron nitride layer, a second wurtzite boron nitride layer and a diamond layer, the diamond layer is arranged between the first wurtzite boron nitride layer and the second wurtzite boron nitride layer and is made of diamond, wurtzite boron nitride is a metastable phase stably existing under normal pressure, and the Vickers hardness of the composite material is larger than 50 GPa. The novel wurtzite boron nitride / diamond composite material disclosed by the invention has high hardness, high toughness and high thermal stability, and the preparation method disclosed by the invention is low in initial raw material price and simple in preparation process.

The invention discloses a method for synthesizing a hierarchical pore MFI molecular sieve membrane based on a sacrificial crystal seed layer, and belongs to the field of zeolite molecular sieve membrane synthesis. The hierarchical pore MFI molecular sieve membrane with a compact selective top layer and a macroporous transition layer with high porosity is successfully constructed on a porous carrier through a surface wet gel secondary growth technology of a sacrificial crystal seed layer. The film layer structure and the gas separation performance are optimized by regulating and controlling the composition, the aging time and the crystallization time of the synthetic gel. The prepared hierarchical pore MFI molecular sieve membrane shows high permeability and excellent selectivity in n-butane / iso-butane separation, and the preparation process is good in repeatability, high in stability and suitable for industrial gas separation application.

This invention discloses a method for preparing a laser-clad anti-sticking steel coating on the surface of a vertical roller, comprising: accurately quantifying the surface morphology and laser process parameters of the anti-sticking steel coating on the vertical roller, namely, forming a heat dissipation channel size control equation based on a Gaussian heat source model and an elliptical double-beta spray gun model, and determining the corresponding cladding process parameters according to the dimensional parameters of the coating's relevant service performance requirements, thereby achieving controllable preparation of the spiral anti-sticking steel coating. This invention, through effective control of the coating's spiral diameter and the size and shape of protrusions and grooves, ensures the coating's high-temperature wear resistance while reducing friction between the steel pipe and the vertical roller, preventing steel sticking and extending the service life of the vertical roller.

The application provides a wurtzite boron nitride / diamond composite material and a preparation method and application thereof. The composite material is composed of two phases of wurtzite boron nitride and diamond, and has a stacked sandwich microstructure, which comprises at least one first wurtzite boron nitride layer composed of wurtzite boron nitride, at least one second wurtzite boron nitride layer composed of wurtzite boron nitride, and a diamond layer composed of diamond and sandwiched between the first wurtzite boron nitride layer and the second wurtzite boron nitride layer. The wurtzite boron nitride is a metastable phase stably existing under normal pressure, and the Vickers hardness of the composite material is greater than 50 GPa. The novel wurtzite boron nitride / diamond composite material has high hardness, high toughness and high thermal stability, and the preparation method has low starting material price and simple preparation process.

The application belongs to the field of electrocatalytic materials and energy conversion technology, and particularly relates to a Ni nanoparticle and Ni monatomic synergistic catalyst as well as a preparation method and application thereof. The preparation steps of the Ni nanoparticle and Ni monatomic synergistic catalyst include: mixing a soluble zinc salt, a soluble nickel salt and an organic ligand in water, then mixing with a solution containing polydopamine, and sequentially performing light-shield aging, drying and pyrolysis to obtain the Ni nanoparticle and Ni monatomic synergistic catalyst. The application provides a strategy of combining a two-dimensional ZIF-L precursor with PDA bifunctional modification, in the catalyst preparation process, the introduced PDA simultaneously acts as a structure directing agent and a metal size control agent, realizing the synergistic coexistence of Ni monatomic and nanoparticles, precise size control and construction of a hollow leaf-shaped carbon-based carrier. By utilizing the hydrogen overflow synergistic effect between the Ni nanoparticle and the Ni monatomic, the catalytic activity, selectivity and stability of the electrocatalytic reduction of CO2 are significantly improved.

The application discloses a method for controllable preparation of nanoscale calcium carbonate by taking regenerated micro powder as a calcium source, and comprises the following steps: taking the regenerated micro powder obtained by treating the hydrated cement-based material as the calcium source, dispersing the regenerated micro powder in deionized water or a water solution containing magnesium ions to form a reaction system, performing a wet carbonation reaction by introducing carbon dioxide gas into the reaction system, and realizing the regulation of the crystal form and particle size of the obtained calcium carbonate product by synergistically regulating the process parameters such as the composition of the reaction medium, the reaction temperature, the reaction time, the carbon dioxide flow rate and the stirring speed, so as to prepare nanoscale calcite crystal calcium carbonate or nanoscale calcite / aragonite composite crystal calcium carbonate.

The present invention discloses the preparation of a silver nanocluster fluorescent composite membrane and its application in the detection of heavy metals. The preparation method of the silver nanocluster fluorescent composite membrane comprises the following steps: (1) mixing an aldehyde-modified nanocellulose solution, a silver ammonia solution and a glutathione solution, and then stirring and reacting them to obtain silver nanocluster micelles; wherein the molar ratio of the aldehyde content of the aldehyde-modified nanocellulose, the silver ammonia complex ions in the silver source solution and the glutathione is 1:1-10:1-10; (2) uniformly mixing the silver nanocluster micelles obtained in step (1) with a glucose solution having a concentration of 10-50% by mass, and evaporating and self-assembling at 20-50°C to form a silver nanocluster fluorescent composite membrane. The silver nanocluster composite membrane prepared by the present invention exhibits strong red fluorescence under ultraviolet light (observed with a black background), and can be used for semi-quantitative, visual and rapid detection of heavy metal ions such as copper ions.

The invention discloses mussel-imitating bacteria responsive injectable hydrogel as well as a preparation method and application thereof, and belongs to the technical field of biological medicines. The hydrogel is formed by compounding a mussel-imitating viscous hydrogel bracket and a bacterial response agent, the viscous hydrogel scaffold is QCS-EC (Quaternized Chitosan) and is formed by non-covalent binding of QCS (Quaternized Chitosan) and EGCG (Epigallocatechin Gallate); the bacterial response agent is a supramolecular nano cross-linked compound TEBox-B12, and is formed by self-assembly of box-shaped quaternized pyridine heterocyclic organic salt molecules TEBox and salt containing suprachaotropic liquid anions B12H12-through hydrogen bonds and electrostatic interaction. The hydrogel disclosed by the invention has NIR-II photo-thermal and photodynamic antibacterial treatment functions, and can be used for efficiently killing bacteria in deep tissues; the hydrogel also has high adhesion, good biocompatibility and injectability, is strong in convenience and applicability, can provide a good healing environment for wounds, promotes fibroblast proliferation and migration, accelerates wound tissue regeneration and healing processes, and reduces scar formation.

A high-transparency, energy-saving LOW-E glass and its preparation method are disclosed, belonging to the field of LOW-E glass technology. The high-transparency, energy-saving LOW-E glass includes a glass substrate and a composite film layer sequentially deposited thereon. The composite film layer includes a bottom layer, a functional layer, and a protective layer. The bottom layer is an antimony-doped silicon dioxide layer with a gradient doping structure, wherein the doping concentration gradually decreases from bottom to top along the thickness direction. The functional layer includes a first functional sublayer and a second functional sublayer. The first functional sublayer is a fluorine-doped tin oxide layer, and the second functional sublayer is a titanium-doped zinc oxide layer, with a compositional gradient transition region formed between the first and second functional sublayers. The protective layer is a silicon nitride layer. The high-transparency, energy-saving LOW-E glass of this invention has high light transmittance, excellent thermal insulation performance, good chemical stability, and can undergo subsequent deep processing.

The present invention provides a Ni-M single-atom alloy catalyst and a preparation method and application thereof. The catalyst is a magnesium-aluminum metal mixed oxide MgAlO X As a carrier, a first metal Ni and a second metal M are loaded, wherein the second metal M is selected from one of the noble metals Pt, Ru, Pd, Rh, Ir, Ag and Au, or one of the non-noble metals Fe, Co, Cu, Zn, Ga, In, Mn, Bi, Cd, Sn. By configuring a mixed metal salt solution of Ni, M, Mg, and Al, a Ni / M / Mg / Al quaternary layered hydroxide material Q is prepared by a coprecipitation method, and then a supported Ni-M single-atom alloy catalyst is obtained by thermal reduction. The catalyst is used in the reaction of selective hydrogenation of 2,6-diamino-3,5-dinitropyridine to prepare 2,3,5,6-tetraaminopyridine, and shows high activity and high selectivity under mild conditions, avoiding the occurrence of side reactions such as excessive hydrogenation under high temperature conditions; it also has the characteristics of good stability, reusability and long life, and has broad prospects in industrial applications.

The application discloses a preparation method of gamma-phase germanium selenide nanosheets. The application realizes controllable preparation of high-quality gamma-phase germanium selenide nanosheets by adopting a normal-pressure vapor deposition method and based on a rapid cooling strategy. The application realizes controllable growth of gamma-phase germanium selenide nanosheets with different lateral sizes by controlling growth temperature. The application does not need to plate a catalyst such as gold on a substrate surface, and the preparation process is relatively simple. The prepared gamma-phase germanium selenide nanosheets have great application potential in flexible sensors, photoelectric devices, especially near-infrared photoelectric detectors and the like. The gamma-phase germanium selenide nanosheets prepared by the application are still very stable after being placed in air for half a year, and also provide a good experimental platform for subsequent physical property research on the material.

This invention discloses a method for preparing an ultrathin ordered macrocyclic molecular membrane. The method involves synthesizing macrocyclic molecules with high polymerization activity and amphiphilic guest molecules. The inclusion complexes formed by the macrocyclic molecules and guest molecules are orderedly assembled using Langmuir-Blodgett (LB) technology. Photopolymerization is then employed to achieve ordered cross-linking of the macrocyclic molecules, resulting in an ultrathin ordered macrocyclic molecular membrane. The macrocyclic molecular membrane prepared by this invention is monomolecular in thickness and possesses good mechanical strength. With the assisted orientation of the amphiphilic guest molecules, the macrocyclic molecules achieve ordered assembly at the water-air interface. The membrane preparation process proposed in this invention is simple, cost-effective, versatile, and easily scalable, making it significant for the field of high-performance separation membranes.

The invention relates to a method for preparing a magnetic metal nickel gradually-thinned nanowire, which comprises the following steps of: (1) irradiating and sensitizing a polymer template by using a fast heavy ion beam to obtain a polymer template with a latent track; (2) sputtering a gold conductive layer on one side of the polymer template of the latent track, and depositing a copper conductive layer on the surface of the gold conductive layer by using electrochemical deposition; (3) etching one side, without the gold-copper conductive layer, of the polymer template of the latent track by adopting an etching solution to obtain a polymer template with a gradually-thinned linear pore channel; (4) electrochemically depositing a magnetic metal nickel gradually-thinned nanowire on one side, without the gold-copper conductive layer, of the polymer template with the gradually-thinned linear pore channel; and (5) stripping the gold-copper conductive layer to obtain the magnetic metal nickel gradually-thinned nanowire. The method is simple and efficient, controllable preparation of the magnetic metal nickel gradually-thinned nanowire array is achieved for the first time, and the small-size magnetic metal nickel gradually-thinned nanowire array with excellent microwave absorption performance is successfully prepared.

The invention discloses a method for preparing high-uniformity iron phosphate from iron-containing waste residues, which comprises the following steps: S1, leaching the iron-containing waste residues, removing impurities, and adding an oxidizing agent to obtain an iron source solution; dissolving a phosphorus source to obtain a phosphorus source solution; s2, respectively pumping the iron source solution and the phosphorus source solution into two feed ports of a high-mixing continuous reactor, and collecting effluent to a stirring reaction kettle; s3, stirring and reacting the effluent in the stirring reaction kettle, aging, separating out precipitate, washing and grinding to obtain an iron phosphate intermediate; and S4, carrying out crystallization treatment on the iron phosphate intermediate, then separating out precipitates, washing, grinding to obtain powder, and carrying out heat treatment to obtain iron phosphate. According to the preparation method of the high-uniformity iron phosphate, disclosed by the invention, the iron-containing waste residues are adopted as an iron source, and iron phosphate and lithium iron phosphate products with high uniformity and excellent performance can be prepared based on an efficient mass transfer technology, so that high-value utilization of wastes is realized, and the production cost advantage is improved.

This invention provides a method and application for the controllable recovery of a specific cobalt-nickel ratio product from a cobalt-nickel mixed solution. The method includes the following steps: adding a complexing agent to the cobalt-nickel mixed solution and adjusting the pH of the solution to acidic, thus obtaining an electrolyte; using the electrolyte as the working electrolyte in an electrodeposition system, performing an electrodeposition reaction under constant potential conditions, causing the specific cobalt-nickel ratio product to deposit on the cathode surface; wherein the cobalt-nickel mixed solution contains cobalt ions and nickel ions. The recovery method of this invention is simple in procedure, reduces production costs, improves recovery efficiency and environmental friendliness, and has good prospects for industrial application.

The invention discloses a preparation method and application of a ratiometric fluorescent paper-based sensor. The preparation method comprises the following steps: (1) preparing a UiO-66-NH2-rhodamine B composite material; and (2) dropwise adding a suspension containing the UiO-66-NH2-rhodamine B composite material into the hydrophilic sensing area of the paper-based substrate, and carrying out a reaction I to obtain the ratiometric fluorescent paper-based sensor, the surface of the paper-based substrate is modified by using carboxymethyl cellulose to introduce a large number of carboxyl groups; the paper-based substrate comprises a hydrophilic sensing area and a hydrophobic area. Due to the built-in self-calibration characteristic of the ratiometric fluorescence sensor disclosed by the invention, the interference of factors irrelevant to analysis can be inhibited, and higher sensitivity and more obvious visual detection effect are shown in qualitative and quantitative analysis processes.

The invention discloses a 2-x-terephthalic acid copper-based MOFs (Metal-Organic Frameworks) micro-nano sheet and a preparation method and application thereof, and the method comprises the following steps: dropwise adding a copper chloride dihydrate solution into a pre-deprotonated 2-x-terephthalic acid solution, stirring to react, and centrifugally washing and drying the product to obtain the 2-x-terephthalic acid copper-based MOFs micro-nano sheet, x is one of methyl, amino or hydroxyl. The 2-x-terephthalic acid copper-based MOFs micro-nano sheet can be used for electrocatalytic reduction of carbon dioxide. The 2-x-terephthalic acid copper-based MOFs micro-nano sheet prepared by the invention has a unique folded sheet structure, the specific surface area and the exposure degree of active sites of the material are remarkably increased, and mass transfer and charge transfer paths are shortened, so that the kinetics and energy efficiency of a catalytic reaction are integrally optimized.

This invention belongs to the field of electronic component technology, and discloses a SnTe material for a nitrogen dioxide gas sensor, its preparation process, and its application. The SnTe material is synthesized via a solvothermal method. The nitrogen dioxide gas sensor mainly consists of a gas-sensitive material and gold interdigitated electrodes. The gas-sensitive material is coated on the surface of the gold interdigitated electrodes with a coating thickness of approximately 15mm to 75mm. The gas-sensitive material is SnTe. This invention provides a simple, low-cost, safe, and controllable TMDC nanomaterial preparation scheme. Using ethanolamine as a solvent and coordinating agent, and potassium hydroxide aqueous solution as a tellurium source activator, this invention synthesizes SnTe nanomaterials in one step via a solvothermal method. The SnTe nanomaterials prepared by this invention achieve a small nanoscale size. A large number of small-sized nanomaterials can effectively increase the sufficient contact between the material and gas molecules, improving the residence rate of gas molecules on the nanomaterial surface.

The invention provides a low-temperature preparation method of an ultrathin silicon nitride film, which comprises the following steps: by taking tris (dimethylamino) silane and ammonia gas as precursors, carrying out a thermal vapor deposition reaction on the tris (dimethylamino) silane and the ammonia gas in an alternate feeding manner under the condition that the temperature of a reaction chamber is 300-400 DEG C to obtain the ultrathin silicon nitride film. According to the method disclosed by the invention, controllable preparation of the ultra-thin nanoscale silicon nitride film is realized within 450 DEG C without depending on plasma generation equipment under relatively mild conditions. According to the method, the ultrathin silicon nitride film with the film thickness angstrom-level precision and the adjustable stoichiometric ratio is prepared by changing the cycle period number and the nitrogen-containing precursor injection time.

The invention discloses a nano-micron pore channel composite perovskite electrode material, a preparation method thereof and application of the nano-micron pore channel composite perovskite electrode material in a solid oxide fuel cell, and belongs to the technical field of inorganic material synthesis. The invention solves the problem of insufficient pore channel exposure rate of the existing solid oxide fuel cell electrode material. Nanoscale polystyrene microspheres are used as a soft template, metal salt is combined, a nanofiber precursor is prepared through an electrostatic spinning method, then sintering is carried out, and the composite perovskite electrode material of a micron-nanoscale pore channel structure is obtained. According to the preparation method provided by the invention, the polystyrene microspheres are subjected to laser sintering, so that spherical nano pore channels are reserved in the fibers, the pore channel exposure probability is further improved, the battery performance is more stable, and moreover, the preparation method provided by the invention can realize controllable synthesis of a composite perovskite electrode material, so that large-scale stable preparation of high-activity electrodes is realized.

The application discloses a kind of modular hydrogel based on liquid shaping technology, preparation method and application thereof.The method first utilizes the plasticity of liquid rubber clay, and obtains the temporary mold of specific shape by pressing or cutting, which is composed of micro-nano particle shell;The mixture containing photosensitive hydrogel precursor, nanoclay and functional factor is injected into the mold and light-cured to form a hydrogel module;Optionally, after removing the particle mold, a functionalized hydrogel module with specific morphology, non-adhesion to the substrate and adjustable mechanical properties is obtained;Finally, different functional modules are bonded and cured by hydrogel precursor to integrate into a modular hydrogel with spatial heterostructure.The application uses micro-nano particle shell as a shapeable and removable temporary mold, realizes the adjustable design of hydrogel macroscopic morphology, mechanical properties and spatiotemporal sequence of drug release, and has wide application prospect in the field of tissue engineering and regenerative medicine.

The invention discloses a method for preparing spherical nano barium fluoride, spherical barium fluoride smaller than 5nm is synthesized by a microemulsion reaction method, and the microemulsion is temperature-responsive and does not contain a surfactant. Controllable preparation of the spherical barium fluoride with the ultra-small size smaller than 5 nm under the surfactant-free condition is achieved for the first time. A ternary surfactant-free microemulsion system composed of diethylene glycol monohexyl ether, octane and water is constructed, the amphiphilic solvent characteristic of diethylene glycol monohexyl ether is used for replacing a traditional surfactant, and the dependence of an existing template method on the surfactant is successfully broken through. The particle size of the obtained BaF2 product is only smaller than 5 nm and enters a strong quantum confinement scale range, and the preparation blank of a barium fluoride material in the field of sub-5-nm ultra-small solid spheres is filled.

This invention relates to the field of lithium-ion battery cathode material technology, specifically a high-performance lithium-rich manganese-based cathode material based on pretreated boron nitride, its preparation method, and its application. The preparation method includes: introducing hydroxyl and amino groups onto the surface of boron nitride nanosheets; preparing a composite precursor powder by mixing a nickel-cobalt-manganese hydroxide precursor, a lithium source, TiO2, a phosphorus source, and pretreated boron nitride; sequentially performing conventional pre-calcination, a first-segment Joule heat treatment, and a second-segment Joule heat treatment; performing a third-segment instantaneous Joule heat treatment, followed by quenching; by introducing a surface-functionalized high thermal conductivity boron nitride network into the bulk phase of the material, and combining a programmed sequential heat treatment of "pre-calcination-two-segment Joule heat treatment" with instantaneous surface melting and quenching, this method effectively solves the inherent thermal gradient problem of the Joule heating method, simultaneously achieving high bulk phase homogenization and surface stabilization, resulting in a product with excellent comprehensive electrochemical performance.

The invention discloses a growth base station for preparing large-size single crystal diamond and a preparation method of the growth base station. The growth base station comprises a base, a main groove and an auxiliary groove located at the bottom of the main groove, and the depth relation meets the following conditions: the depth of the auxiliary groove is 1t; and the seed crystal thickness is less than or equal to the sum of the auxiliary groove depth and the main groove depth. The preparation method comprises the following steps: S1, screening seed crystals; s2, cloning, separating and processing the seed crystal to obtain a prepared seed crystal with the surface roughness Ra being less than or equal to 10nm and the thickness difference being less than or equal to 5mu m; s3, finishing the growth surface and the side surface of the prepared seed crystal, and determining the step flow direction; s4, loading the seed crystal into the auxiliary groove of the base station according to the step flow direction, fixing, and carrying out first epitaxial growth under negative bias; and S5, carrying out vacuum annealing, cutting polishing and secondary epitaxial growth on the growth body. The stable and closed growth environment is provided for the seed crystal through the base station structure, and the process is combined, so that the crystal quality at the splicing seam is effectively improved, and the preparation of the high-quality large-size single crystal diamond is realized.

The invention belongs to the technical field of nano material preparation, and particularly relates to a method for preparing a few-atomic-layer ultrathin SnSe nanosheet based on an intercalation compound precursor. The invention discloses a method for preparing a low-atomic-layer ultra-thin (lt; lt) material by taking ethanolamine as an intercalator based on an intercalation-de-intercalation strategy. According to the method, ethanol amine is used as an intercalator through a hydrothermal method, an ethanol amine intercalated SnSe hybrid precursor is firstly synthesized, then the ultrathin SnSe nanosheet is obtained through deintercalation treatment, the thickness of the prepared nanosheet can reach the atomic level (about 2-3 atomic layers), and the method is simple in process, low in cost, high in product quality and suitable for industrial production. The problems that an existing process is complex, and product size and thickness are difficult to control are solved. In addition, the ultrathin SnSe nanosheet prepared by the method shows excellent application prospects in the fields of piezoelectric devices, photoelectric detection, flexible electronics, energy conversion and the like.

The invention belongs to the technical field of porous carbon materials, and particularly relates to a gradient pore porous carbon material and a preparation method and application thereof. The preparation method comprises the following steps: mixing a carbon source precursor, a soft template and a densification carbonization component, adding a gas release hole regulator and a heteroatom introducing agent, mixing, mixing with a solvent, granulating, carrying out pre-curing treatment and segmented carbonization treatment, carrying out graded gas activation treatment, and finally carrying out post-treatment and heat treatment to obtain the carbon-based composite material. The gradient pore porous carbon material is obtained. According to the method, a continuous mesoporous channel network is constructed through a phase separation soft template, fine trimming and concentration of micropore diameters and channel dredging are achieved through graded gas activation, and the compaction density and the electric conduction continuity are improved by introducing a char-forming densification and structure shape locking strategy; the gradient pore porous carbon material which has high specific capacitance, high rate performance and high volume capacitance and is suitable for thick electrodes and high-surface-density electrodes is obtained, and the gradient pore porous carbon material has the advantages of being mild in process, good in repeatability, easy to amplify and low in aftertreatment burden.