1192 results about "Nickel oxide" patented technology

The invention discloses a negative temperature coefficient medium-entropy thermistor material as well as a preparation method and application thereof. According to the invention, manganese dioxide, nickel oxide, cobalt sesquioxide, zinc oxide and copper oxide are used as raw materials, and a solid-phase reaction method is adopted to prepare the negative temperature coefficient medium-entropy thermistor material with a chemical formula of (NiX1CoX2ZnX3CuX4) Mn2O4. Wherein the values of X1, X2, X3 and X4 are 0.075-0.425, and X1 + X2 + X3 + X4 = 1. The negative temperature coefficient medium-entropy thermistor material is of a single spinel structure. The material has the hysteresis diffusion effect of medium-entropy ceramic, and by combining the coordinated optimization effect of multiple components, the material constant and the resistivity of the thermal sensitive ceramic can be remarkably reduced, and the anti-aging performance can be improved.

The invention belongs to the technical field of energy storage materials, and particularly relates to a high-entropy oxide Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2O and an ultrafast synthesis method and application thereof. According to the preparation method, ferroferric oxide, cobalt oxide, nickel oxide, copper oxide and zinc oxide with equal molar ratio are adopted as direct synthesis raw materials, toxic gases such as chlorine and nitrogen dioxide generated in the synthesis process of a metal salt precursor are avoided, and the uniformly distributed single-phase high-entropy oxide is synthesized in an ultrafast manner within 10 seconds by using a Joule heating technology; the synthesized high-entropy oxide is used as a lithium ion battery negative electrode material, and shows more excellent electrochemical performance and cycling stability compared with other high-entropy oxides prepared from transition metals with different proportions; in the preparation process, extra additives are not needed, operation is easy, the synthesis speed is high, the yield is high, element distribution is uniform, and the method has the advantages of being low in cost, high in efficiency and free of pollution and has the industrialization prospect.

The invention relates to a catalytically graphitized silicon-carbon composite material, a preparation method thereof and a lithium ion battery. The preparation method comprises the following steps: providing a porous carbon precursor, sequentially carbonizing, activating and pore-forming, pickling, washing to be neutral, passivating to remove impurities, and then crushing and grading to obtain a porous carbon substrate with the particle size D50 of 5-20 microns; adding a graphitization catalyst into the porous carbon substrate for blending, and carrying out heat treatment at 800-1000 DEG C for 2-6 hours for catalytic modification to obtain modified porous carbon; and putting the obtained modified porous carbon into a chemical vapor deposition reaction furnace, and depositing silicon particles to obtain the catalytically graphitized silicon-carbon composite material. Wherein the graphitization catalyst comprises any one or more of potassium ferrate, iron oxide, nickel oxide, boron, aluminum, titanium, Fe-Si alloy and P-Ni alloy. The graphite catalyst is added to perform catalytic graphitization modification on the porous carbon substrate, so that the energy density, the cycle life and the rate capability of the battery are remarkably improved, and the application requirements of the high-performance battery are met.

The invention provides a vertical structure ultraviolet photoelectric detector and a preparation method thereof. The ultraviolet photoelectric detector is of a vertical structure, the design facilitates light absorption of the ultraviolet photoelectric detector, the light utilization rate of the ultraviolet photoelectric detector is improved, and compared with a horizontal structure, the transmission distance is shortened, and the cost is low; the ultraviolet photoelectric detector provided by the invention has a relatively high switching ratio of light and dark current and relatively small dark current, and also has a very high response speed under the condition of keeping the switching ratio of light and dark current and the dark current; a PN junction is formed between the nickel oxide hole transport layer and the beta-phase gallium oxide single crystal, so that the ultraviolet photoelectric detector has self-driving performance; in the manufacturing process, the substrate is used as a supporting frame, and the extraction electrode is packaged in one step through the conductive adhesive tape, so that 3-5 photoetching steps of a traditional horizontal structure are omitted, the process is simplified, and the process manufacturing is simpler.

The invention relates to the technical field of electrochromism coating, in particular to an electrochromism device coating process and method, and the electrochromism device coating process comprises the following steps: step 1, substrate pretreatment: cleaning attachments on the surface of a flexible substrate through ultrasonic cleaning and plasma treatment; step 2, conducting layer deposition treatment: depositing an indium tin oxide (ITO) conducting layer on the substrate at the deposition temperature of 100-380 DEG C, the thickness of 200-350 nm and the vacuum degree of less than or equal to 10 <-5 > Pa; step 3, electrochromic layer deposition treatment: sequentially depositing a tungsten oxide (WO3) layer and a nickel oxide (NiO) layer through a magnetron sputtering process, and controlling the film thickness ratio of NiO to WO3 to enable the ratio of NiO / W to be 0.25-0.357; 4, annealing treatment is conducted, specifically, annealing is conducted for the first time at the temperature of 200-500 DEG C, and the annealing time is 200-300 seconds; and secondary annealing is conducted, specifically, annealing is conducted at the temperature of 400 DEG C, and the annealing time ranges from 200 seconds to 800 seconds. The effect of improving the yellow ground color of the electrochromic device is achieved.

The application provides a method for grading diesel deep hydrodesulfurization catalysts, which comprises the following steps: loading catalysts containing AlPO4-5 phosphorus aluminum molecular sieves and catalysts containing ETS-10 titanium silicon molecular sieves in the upper and lower parts of a fixed bed hydrogenation reactor respectively according to a loading mass ratio of 1:3-3:1, so that diesel is subjected to hydrodesulfurization reaction through catalysts containing AlPO4-5 phosphorus aluminum molecular sieves first and then through catalysts containing ETS-10 titanium silicon molecular sieves; the carrier of the catalysts containing AlPO4-5 phosphorus aluminum molecular sieves comprises AlPO4-5 phosphorus aluminum molecular sieves and aluminum oxide powder, the carrier of the catalysts containing ETS-10 titanium silicon molecular sieves comprises ETS-10 titanium silicon molecular sieves and aluminum oxide powder, and the active components of the two kinds of catalysts respectively comprise a combination of two or three of nickel oxide, molybdenum oxide and cobalt oxide. The sulfur content of the hydrogenated diesel obtained through the method can be as low as 10 μg / g or below.

The invention discloses a preparation method of a high-capacity lithium iron manganese phosphate cathode material. In the method of the invention, by doping nickel and modifying polyethylene glycol, the intrinsic conductivity of the material is improved. At the same time, the lattice distortion caused by doping inhibits the growth of grains, improves the grading of particles, shortens the diffusion path of lithium ions. Meanwhile, nickel in nickel and fluorine modified polyethylene glycol can form nickel oxide on the surface of carbon sources such as carbon black or carbon fiber, which promotes the electron and ion transport between the cathode material and the electrolyte to a certain extent, improves the energy density and cycle performance of the battery. Fluorine can improve the interfacial composition between the carbon source and the cathode material, promote the transfer and diffusion of lithium ions, and improve the charge / discharge rate and capacity retention of the battery. Therefore, doping nickel and modifying polyethylene glycol in the invention have a synergistic effect. Especially when the molar amount of doped nickel is 0.02, the prepared battery has a high capacity and excellent rate performance.

The invention discloses conductive paste, a conductive electrode, a preparation method of the conductive electrode and a crystalline silicon solar cell, and belongs to the technical field of photovoltaic cells, the conductive paste comprises glass powder, silver, nickel and an organic carrier, the glass powder comprises B2O3, corrosive oxide and non-corrosive oxide, and the nickel is added to replace part of silver, so that the usage amount of silver in the conductive paste is reduced, and the cost is reduced. In addition, the molar ratio range of the corrosive oxide and the non-corrosive oxide in the glass powder is limited to be 0.7-2.6. The first passivation layer arranged on the boron diffusion emitter is opened during high-temperature sintering, and the oxidability and the flowability of the glass powder can be balanced to inhibit or delay the formation of an oxidized nickel shell on the surface of the nickel powder, so that a laser enhanced contact post-treatment process is matched; and the photoelectric conversion efficiency of the crystalline silicon solar cell is ensured.

The invention relates to the technical field of new energy, in particular to an extensible composite hole transport layer and a perovskite solar cell based on the extensible composite hole transport layer, and a preparation method of the perovskite solar cell comprises the following steps: forming a nickel oxide film on transparent conductive glass through magnetron sputtering; soaking the nickel oxide thin film to form a self-assembled monomolecular layer; forming a perovskite active layer on the self-assembled monomolecular layer; forming an electron transport layer on the perovskite active layer; and forming an electrode on the electron transport layer. According to the method, the preparation size of the hole transport layer can be expanded, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

The invention discloses a preparation method of a composite lithium-rich and lithium-supplement additive, which comprises the following steps: taking lithium ferrite as a core, preparing NiO (at) lithium salt by adopting an ALD atomic deposition method, fully and uniformly mixing carbon-coated lithium ferrite and the NiO (at) lithium salt, and sintering to prepare the composite lithium-rich and lithium-supplement additive. According to the invention, the advantages of high lithium supplement capacity of lithium ferrite, less gas production of lithium nickelate and good environmental adaptability are fully exerted, and the lithium supplement agent with high capacity and good stability is obtained; the nanometer nickel protoxide is in full contact with a lithium salt coating layer prepared by an ALD method, subsequent sintering is facilitated, preparation can be performed at a lower temperature, cost reduction is facilitated, meanwhile, the nickel protoxide and the peripheral lithium salt coating layer are subjected to a solid solution reaction, and residual lithium on the surface of lithium ferrite of a nuclear body can be obtained. The'two-channel lithium acquisition mode 'can reduce the overall residual alkali amount of the material, and is beneficial to improving the processing performance of subsequent battery slurry.

The invention relates to the technical field of new energy materials, in particular to a metal oxide heterojunction catalyst and a preparation method and application thereof in hydrogen peroxide production. The preparation method comprises the following steps: taking soluble zinc salt and urea as raw materials, carrying out hydrothermal reaction to obtain zinc oxide, then taking soluble nickel salt and zinc oxide as raw materials, carrying out coprecipitation reaction under the action of ammonium bicarbonate, and calcining in air to obtain the metal oxide heterojunction catalyst. The preparation steps are simple and convenient, the product is prepared in the air atmosphere, in the obtained metal oxide heterojunction catalyst, the surfaces of the zinc oxide microspheres are uniformly coated with the nickel oxide nanosheets, the specific surface area is large, the number of active sites is large, the nickel oxide nanosheets and the zinc oxide microspheres form a heterojunction structure, and the metal oxide heterojunction catalyst has good catalytic activity. The defects of a catalyst for producing hydrogen peroxide through electro-catalysis water oxidation and a preparation method in the prior art are overcome.

The invention provides a wet treatment process for laterite-nickel ore. The wet treatment process comprises the following steps: S1, carrying out acid leaching treatment on the laterite-nickel ore by adopting inorganic acid to obtain leached ore pulp; s2, the leached ore pulp is sequentially subjected to liquid-solid separation and countercurrent washing, and washed pulp and leached residues are obtained; s3, a first oxidizing agent and a first neutralizing agent are added into the washed slurry for iron and aluminum removal treatment, and a solution with iron and aluminum removed and iron and aluminum slag are obtained; s4, carrying out nickel and cobalt precipitation treatment on the solution subjected to iron and aluminum removal, so as to obtain precipitated slurry; s5, continuously carrying out dense separation treatment on the precipitated slurry to obtain underflow and overflow; and S6, the underflow is subjected to washing aftertreatment in sequence, and a cobalt nickel hydroxide product is obtained. The invention provides a short-process wet treatment process for laterite-nickel ore, the production cost and energy consumption are reduced, and meanwhile, the recovery rate of nickel and cobalt, the overall recovery rate of scandium and the quality of nickel-cobalt oxide products are improved.

The invention discloses an alkaline electrolyzed water diaphragm based on nickel oxyhydroxide and a preparation method and application of the alkaline electrolyzed water diaphragm, and relates to the technical field of composite diaphragms.The alkaline electrolyzed water diaphragm is prepared through a phase inversion method, and nanometer nickel oxyhydroxide NiOOH particles are selected as inorganic nanometer filler; the mass percent of the nickel oxyhydroxide in the membrane casting solution is 15-30%. A strong chemical bond formed by nickel ions and hydroxyl in the hydroxyl nickel oxide crystal endows the material with excellent structural stability, and the material shows excellent solubility resistance, hydrolysis resistance and structural collapse resistance in a strong alkaline electrolysis environment and can tolerate high-concentration OH <-> erosion for a long time; meanwhile, the intrinsic high-oxidation-resistance characteristic is achieved.

The invention discloses a method for preparing a hole transport layer of a perovskite solar cell by direct-current sputtering of a metallic nickel target, which comprises the following steps of: performing direct-current sputtering twice by using the metallic nickel target in atmospheres with different oxygen contents to form a bottom-layer nickel oxide film and a top-layer nickel oxide film; and carrying out annealing treatment, supercritical fluid treatment and alkali metal halide salt surface passivation to prepare the nickel oxide hole transport layer for the perovskite solar cell. According to the method, the large-area hole transport layer can be prepared, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

The invention discloses a process for treating nickel wastewater containing nickel acetate cleaning water and nickel acetate concentrated water, which comprises the following steps: S1, filtering nickel wastewater, S2, carrying out primary concentration treatment, S3, carrying out secondary concentration treatment, S4, treating by a sodium metaaluminate method, S5, carrying out collaborative filtration treatment, and S6, discharging RO (Reverse Osmosis) produced water up to the standard. The method comprises the following steps: primarily enriching nickel ions by adopting primary nickel concentration treatment and secondary nickel concentration treatment, adding a sodium metaaluminate solution into a mixed solution, enabling the pH value of the mixed solution to be 8-12, enabling the nickel ions to react with hydroxyl ions to generate a nickel hydroxide precipitate, adding a sulfuric acid solution to adjust the pH value of the mixed solution back to 6.5-7.5, hydrolyzing sodium metaaluminate to generate an aluminum hydroxide precipitate, and carrying out secondary nickel concentration treatment on the aluminum hydroxide precipitate; aluminum hydroxide adsorbs nickel hydroxide to form a composite precipitate, aluminum ions and nickel ions are subjected to a competitive complexation reaction, and a flocculating agent is added into a mixed solution to form a flocculent precipitate, so that the reaction time is short, the nickel content in the nickel sludge can be greatly increased, the treatment period can be shortened, and the operation cost can be reduced.

The invention provides a nickel-based supported catalyst, a preparation method and application thereof, and a carbon dioxide methanation method, and belongs to the technical field of catalysts. The nickel-based supported catalyst provided by the invention comprises a carrier and nickel oxide supported on the surface and in pore channels of the carrier, the carrier comprises carbonate and / or citrate. The carbonate and / or citrate are / is used as the carrier, the nickel-based supported catalyst is synthesized by adopting a solution combustion method, the nickel-based supported catalyst has larger specific surface area and smaller particle size, the nickel oxide and the carrier have a stronger mutual combination effect, the nickel-based supported catalyst has excellent stability, and CO2 methanation can be catalyzed for a long time under a low-temperature condition. The nickel-based supported catalyst is combined with the low-temperature plasma, so that CO2 methanation can be catalyzed at normal temperature and normal pressure, and the catalyst has high CO2 conversion rate and CH4 selectivity.

The invention discloses a preparation method of a nickel-based catalyst and the nickel-based catalyst. The preparation method of the nickel-based catalyst comprises the following steps: S1, completely dissolving an acid source, cerium salt and a solvent; s2, carrying out hydrothermal reaction on the solution obtained in the step S1; s3, carrying out solid-liquid separation on the product obtained in the step S2, and washing, drying and calcining the obtained solid product to form a carrier which is cerium dioxide derived from a metal organic framework; s4, an active component is loaded on the carrier, and the active component is metallic nickel or nickel oxide. According to the preparation method of the nickel-based catalyst, the nickel-based catalyst with relatively high specific surface area and developed mesoporous channels can be prepared, thermal agglomeration of active sites of metal nickel can be avoided, and the stability and catalytic performance of the nickel-based catalyst are improved.

The application provides a lithium ion battery and an electric device, the lithium ion battery comprising a positive electrode sheet and an electrolyte, an active substance in the positive electrode sheet comprising a phosphate lithium positive electrode material and a lithium nickel cobalt manganese oxide, the electrolyte comprising a positive electrode film former, a negative electrode film former and a lithium salt, the lithium salt comprising lithium hexafluorophosphate and a lithium bisfluorosulfonylimide salt, the lithium ion battery satisfying the following formula: wherein NL is a mass ratio of the lithium nickel cobalt manganese oxide and the phosphate lithium positive electrode material, S alt is a value of a molar concentration of the lithium hexafluorophosphate and the lithium bisfluorosulfonylimide salt in the electrolyte in mol / L, and A dd is a mass ratio of the positive electrode film former and the negative electrode film former. The application can adjust the ratio of the positive electrode film former and the negative electrode film former and the ratio of the high-heat-resistance lithium salt according to the mixing ratio of the ternary material doped in the lithium manganese iron phosphate or the lithium iron phosphate, so that the cycle performance of the battery is improved.

The invention discloses a rare earth element doped hydrogen evolution electrocatalyst and a preparation method and application thereof. The rare earth element doped hydrogen evolution electrocatalyst comprises rare earth element doped nickel oxide serving as a carrier and ruthenium atoms anchored on the carrier. According to the rare earth element-doped hydrogen evolution electrocatalyst provided by the invention, the adsorption of hydroxyl is enhanced by doping the oxyphilic rare earth element with NiO, the hydrogen conversion on the surface of Ru is promoted by a rare earth element / NiO carrier, and the rare earth element / NiO and Ru generate a definite synergistic effect to jointly promote the dissociation of water, so that the rare earth element-doped hydrogen evolution electrocatalyst shows very high catalytic activity in alkaline HER; a new thought is provided for accelerating alkaline HER reaction kinetics. In an alkaline HER test, the rare earth element doped hydrogen evolution electrocatalyst provided by the invention can reach the current density of 10mA cm <-2 > by only needing the overpotential of 38mV; and after a stability test is carried out for 50 hours, the overpotential is not attenuated.

The invention discloses a method for efficiently co-producing benzoquinone and cyclohexanone based on electrochemical oxidation / reduction of phenol, which adopts an acid-base mixed electrochemical electrolytic tank, the anode electrolyte is alkaline electrolyte, the cathode electrolyte is acidic electrolyte, the anode electrode is nickel foam loaded with nickel sulfide-nickel oxide composite nanosheets, and the cathode electrode is nickel foam loaded with nickel sulfide-nickel oxide composite nanosheets. The cathode electrode is a palladium-nickel-boron nanoparticle alloy with nitrogen-doped porous carbon as a carrier, and the anode electrolyte and the cathode electrolyte are separated by a bipolar membrane; the phenol is added into the anolyte and the catholyte, so that the phenol is electrochemically oxidized by the anode to generate an additional product benzoquinone with high economic value, and meanwhile, the phenol is catalyzed by the cathode to be reduced to generate an additional product cyclohexanone with high economic value. The whole system only needs to consume acid and alkali, the method has the advantages of being good in environmental protection effect and considerable in capacity, and the electrochemical electrolytic tank is good in stability, simple in preparation method, low in cost and easy to achieve large-scale production and has the potential to be applied to large-scale treatment of acid and alkali wastewater containing phenol in industry.

The present invention relates to the technical field of heavy oil hydrodesulfurization, and discloses a hydrodesulfurization catalyst preparation process, which comprises: adding deionized water, a nickel source, a molybdenum source and a dispersant into a reaction container, stirring to obtain a metal solution, pouring into a container filled with gamma-Al2O3, impregnating, drying, and roasting to obtain the hydrodesulfurization catalyst. The dispersing agent contains a large number of nitrogen atoms and a plurality of carboxyl groups and hydroxyl groups, has very strong coordination chelation performance on nickel and molybdenum, improves the dispersity of nickel and molybdenum precursors, enables the nickel and molybdenum precursors to be uniformly impregnated into a gamma-Al2O3 carrier, and nickel oxide and molybdenum oxide are uniformly distributed in the gamma-Al2O3 carrier after calcination, so that the nickel and molybdenum oxide-modified gamma-Al2O3 composite material is prepared. The obtained hydrodesulfurization catalyst can expose more nickel-molybdenum catalytic active centers, effectively catalyzes and removes sulfur-containing substances such as thiophenes in straight-run diesel oil, shows a higher desulfurization rate, and improves the quality of oil products.

The invention provides a perovskite photovoltaic cell, a preparation method thereof and a laminated cell, relates to the technical field of photovoltaics, and aims to solve the problem of low photoelectric conversion efficiency of the perovskite photovoltaic cell. The perovskite photovoltaic cell comprises a perovskite light absorption layer and a hole transport layer stacked on one side of the perovskite light absorption layer, the hole transport layer comprises a hole transport material and benzene sulfonate, and the hole transport material comprises nickel oxide, [2-(3, 6-dimethoxy-9H-carbazole-9-yl) ethyl] phosphonic acid, [4-(3, 6-dimethoxy-9H-carbazole-9-yl) ethyl] phosphonic acid, benzenesulfonate, and nickel oxide. The phosphonic acid is one or more of [3, 6-dimethoxy-9H-carbazole-9-yl) butyl] phosphonic acid, [6-(3, 6-dimethoxy-9H-carbazole-9-yl) butyl] phosphonic acid, and [6-(3, 6-dimethoxy-9H-carbazole-9-yl) hexyl] phosphonic acid. The perovskite photovoltaic cell improves the photoelectric conversion efficiency.

The invention relates to a perovskite photovoltaic cell and a preparation method thereof. The perovskite photovoltaic cell comprises a first charge transport layer, an interface modification layer and a perovskite light absorption layer which are sequentially stacked from bottom to top, the first charge transport layer is a hole transport layer, and the first charge transport layer contains nickel oxide; the interface modification layer contains a first modification material, and the first modification material comprises a cerium halide. Nickel oxide (NiOx) is used as a hole transport layer, and an interface modification layer containing cerium halide is arranged between the hole transport layer and a perovskite light absorption layer. Firstly, the interface modification layer of the cerium halide can effectively reduce the concentration of Ni < 3 + > ions released by the hole transport layer, and also can greatly reduce lead (Pb0) and iodine (I2) decomposed from the perovskite light absorption layer, thereby playing a role in effectively inhibiting the formation of defects on the contact surface of the hole transport layer and the perovskite light absorption layer, and reducing the non-radiative recombination at the interface.

A coated positive electrode material and a preparation method therefor, a positive electrode sheet and a secondary battery, the coated positive electrode material comprising an inner core and a coating layer covering at least part of the outer surface of the inner core. The inner core contains lithium nickel oxide, and the coating layer contains a lithium-containing amorphous polymer, LiPO2F2 and metal fluoride being distributed in the lithium-containing amorphous polymer. The metal fluoride can reduce interfacial side reactions and avoid the erosion to the positive electrode material by HF, and the lithium-containing amorphous polymer and the metal fluoride distributed therein and having good stability help to avoid direct contact between the inner core and an organic electrolyte, thus alleviating electrode / electrolyte interfacial side reactions and impedance growth during cycling. The lithium-containing amorphous polymer has good lithium ion transmission capacity, and the LiPO 2F2 can form a low-impedance electrode / electrolyte interfacial film having high ionic conductivity and stable electrochemical performance, and the synergistic effect of the two improves the dynamic performance of the positive electrode material.

The invention relates to the technical field of catalyst preparation, in particular to a deep hydrodenitrogenation and desulfurization catalyst and a preparation method thereof. According to the preparation method, a novel hydrodenitrogenation and desulfurization catalyst is obtained by redesigning raw materials of the catalyst and a preparation process of the catalyst. The raw material is a pseudo-boehmite product, and the active components comprise 18-25% of molybdenum oxide, 3.3-5.5% of nickel oxide and 1-3% of silicon oxide. The catalyst not only solves the problem of easy coking, but also prolongs the service life of the product to 2-3 years, can effectively reduce the use amount of the hydrodenitrogenation and desulfurization catalyst, reduces the use cost of the hydrodenitrogenation and desulfurization catalyst, and improves the hydrodenitrogenation and desulfurization effect of a reactor.

The invention provides a gas sensor and a method for preparing the gas sensor through laser direct writing. The method comprises the following steps: enabling a metal electrode to be in contact with laser direct writing ink, wherein the laser direct writing ink comprises a nickel source, a porous structure guiding agent and a solvent; laser irradiates a specified contact area of the metal electrode and the laser direct-writing ink, so that the metal electrode absorbs the laser to generate heat so as to form a hydrothermal reaction area in the specified contact area, and the laser direct-writing ink in the hydrothermal reaction area is subjected to a hydrothermal reaction, so that porous nickel hydroxide grows on the metal electrode, and a precursor structure is obtained; and carrying out annealing treatment on the precursor structure so as to convert the porous nickel hydroxide into porous nickel oxide, thereby obtaining the gas sensor. The gas sensor provided by the invention has the porous nickel oxide which has a relatively large specific surface area, so that the effective contact area between the gas sensor and target gas can be increased, and the gas responsivity of the gas sensor is improved.

The present application belongs to the field of diamond preparation, and discloses a high-quality single-crystal diamond preparation method for removing polycrystal defects. Through screen printing and plasma-assisted etching, the (100) surface around the black point-shaped polycrystal is directionally etched by cerium oxide, and a square groove is etched. Then, the slurry of iron oxide or nickel oxide is printed by screen printing, the black point-shaped polycrystal is covered with the slurry, and the black point-shaped polycrystal is removed by plasma-assisted etching. Then, the etched groove is filled by a horizontal growth process, so that the growth defects can be removed, and high-quality single-crystal diamond can be obtained. The present application can greatly reduce the waste rate of single-crystal diamond products and improve the utilization rate of single-crystal diamond. The present application is beneficial to saving production cost and improving efficiency.

The invention discloses porous chlorine dioxide slow-release preservative paper and a preparation method thereof.The porous chlorine dioxide slow-release preservative paper comprises a paper base, a porous carrier is fixed to the paper base through oxidized starch glue, and sodium chlorite, an activating agent and a stabilizing agent are loaded on the porous carrier; the porous carrier is one of aluminum oxide, titanium oxide, cobalt oxide, zinc oxide, copper oxide, iron oxide, cerium oxide, zirconium oxide, nickel oxide, manganese oxide, praseodymium oxide and lanthanum oxide with a porous structure. The slow release of chlorine dioxide can be stably and effectively realized, the release period of chlorine dioxide is prolonged, and long-acting stable sterilization and disinfection effects are realized.