266results about How to "Lower overpotential" patented technology

The invention discloses a high-performance ultrathin nitride electro-catalyst with functions of producing hydrogen and oxygen by means of electrochemically totally decomposing water, a method for synthesizing the high-performance ultrathin nitrite electro-catalyst and application thereof. A chemical formula of the high-performance ultrathin nitride electro-catalyst is (Fe<X>Ni<1-X>)<4>N, and the x is larger than 0 and is smaller than 1. The nitrite electro-catalyst is of an ultrathin nanometer plate structure, the size of the nitrite electro-catalyst is 50-100nm, and the thickness of the nitrite electro-catalyst is 1.5-3nm. The method includes synthesizing NiFe hydrotalcite precursors at first; nitriding the NiFe hydrotalcite precursors at high temperatures under the protection of ammonia gas to obtain end products. The high-performance ultrathin nitride electro-catalyst, the method and the application have the advantages that series of nitrite have large specific surface areas, are good in electron conductance and are excellent in performance during electro-catalytic water total-decomposition reaction, limiting currents are higher than limiting currents of Pt/C during electro-catalytic hydrogen evolution reaction (HER), and the performance of the nitride in various aspects are superior to the performance of corresponding oxide NiFe-MMO during oxygen evolution reaction (OER); the electro-catalyst is low in cost, easy and convenient to operate, simple in process and excellent in catalytic performance, and fundamental application research on materials in the field of electro-catalysis can be provided.

The invention provides a negative electrode plate for a lithium metal battery. Metallic lithium plates and sponges are compressed to obtain the negative electrode plate. The negative electrode plate has the advantages that the traditional lithium metal battery structures can be simplified when the negative electrode plate is applied to the lithium metal battery, electron barrier effects can be realized by sponge elastic interface layers instead of diaphragms, and volume change and the instability of interfaces inside the battery can be relieved by elastic interface materials in battery cycle;sponge medium layers are excellent in electrolyte solution wettability, and are high in thermal deformation resistance as compared with common polypropylene diaphragms; elastic three-dimensional framework structures of the sponges are favorable for inhibiting dendrite growth in lithium metal battery cycle procedures and relieving the volume change of negative electrodes, and accordingly further development of the lithium metal battery can be promoted from another angle by composite metal lithium negative electrodes which are designed by the aid of sponge materials and are free of diaphragm structures.

A single-cell-thickness nano porous cobalt oxide nanosheet array electrocatalytic material is characterized in that a metal-doped cobalt oxide primary nanosheet array is perpendicularly grown on a conductive substrate, a porous nanosheet is obtained from each primary nanosheet, and the nanosheets are of porous structure; the material is used as an electrocatalyst for oxygen evolution reaction; the material also has excellent hydrogen evolution performance and may function as a bifunctional catalyst for an alkaline full-decomposition water system. The invention has the advantages that the material can effectively reduce overpotential and peaking potential of oxygen evolution reaction, increase conversion rate of single cobalt atoms and operate stably and continuously in a strong alkali environment; the material has excellent oxygen evolution reaction performance and can be applied as an anode and cathode of a full-decomposition water system, effectively reducing trough voltage; the material is simple to prepare, convenient to operate, low in cost and environment-friendly, and new idea and strategy are provided for the guide design and performance optimization of the bifunctional catalyst for the full-decomposition water system.

The invention discloses a three-dimensional self-supported lithium-loving carrier-packaged metal lithium composite negative electrode and a preparation method thereof. The three-dimensional self-supported lithium-loving carrier-packaged metal lithium composite negative electrode comprises the following steps of 1) carbonizing melamine foam in an inertia atmosphere to obtain a nitrogen-rich lithium-loving three-dimensional self-supported carrier; and 2) packaging metal lithium in holes of the three-dimensional self-supported carrier to obtain the metal lithium composite negative electrode. Carbon sponge obtained by carbonization of melamine foam is used as a metal lithium carrier, and the metal lithium composite negative electrode has effects of guiding metal lithium to be uniformly deposited and preventing dendrite from being generated. Lithium-loving functional groups are uniformly arranged on the carrier, a lithium-loving coating layer is deposited on a hole surface of the carrier, the lithium-loving performance of the carrier is improved, the volume change of the metal lithium electrode during the circulation process is effectively buffered, moreover, the lithium-loving functional groups uniformly arranged on the three-dimensional carrier are used as active sites for metal lithium deposition, the nucleation over-potential is reduced, uniform nucleation of metal lithium can be effectively controlled, so that the dendrite generation is prevented.

The invention provides preparation of a graphene polyaniline modified carbon cloth electrode material, and a method for accelerating the acclimation of a bio-anode, and relates to electrode preparation and bio-anode acclimation. A purpose of the present invention is to solve the technical problem of poor electron transfer efficiency of existing bioelectrochemical anode. The graphene polyaniline modified carbon cloth electrode material preparation method comprises: loading graphene oxide onto a carbon cloth, immersing into a sodium borohydride solution, reducing, immersing into an aniline monomer solution, adding a curing agent solution in a dropwise manner, and polymerizing to obtain the graphene polyaniline modified carbon cloth electrode material. According to the present invention, with the application of the graphene polyaniline modified carbon cloth electrode material as the anode in the bioelectrochemical system reactor, the operation is performed after the starting until the output potential is stable so as to complete the acclimation; and the graphene polyaniline modified carbon cloth electrode material can be used in wastewater treatment.

The invention relates to the technical field of microbiological fuel cells and provides methods for preparing and applying a composite anode of a microbiological fuel cell. The composite anode contains an inorganic catalyst and polyaniline, has high electric catalytic performance and can remarkably enhance the output power density of the cell. The method for preparing the composite anode comprises the following steps of: performing initiation by using an inorganic initiator, such as manganese dioxide or ammonium metavanadate to synthesize the polyaniline; sulfonating the polyaniline at a low temperature; and pressing an electrode. A marine microbiological fuel cell which contains marine sediments and a sewage microbiological fuel cell are assembled by using the composition anode and a method for specifically testing and analyzing the cell performance is provided. A result indicates that the output power density of the cell is greatly enhanced, the maximum output power density of the composite anode, which contains a manganese compound and the polyaniline is 140.647mW/m<2> and is 4.12 times that of an unmodified anode. The maximum output power density of the composite anode, which contains a vanadium compound and the polyaniline is 187.06mW/m<2> and is 5.48 times that of the unmodified anode.

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

The invention discloses a method for preparing modified SnO2 electrode and application of method for preparing formic acid by photoelectric catalytic reduction of CO2, and belongs to the field of photoelectric catalysis. The problems of low visible light utilization, low catalytic activity, poor product selectivity, high reaction overpotential and competition of hydrogen evolution reaction in theprocess of reduction in the reaction of existing photoelectric catalytic reduction of CO2 are solved. A simple one-step hydrothermal method is used for preparing metal and non-metal co-doping modifiedSnO2 catalyst and preparing the metal and non-metal co-doping modified SnO2 catalyst into an electrode to be applied to preparing the formic acid by the photoelectric catalytic reduction of the CO2,the prepared metal-non-metal co-doping modified SnO2 electrode exhibits good catalytic activity and selectivity for reaction of preparing the formic acid by the reduction of the CO2, and the overpotential needed for the reduction can be effectively reduced. The overpotential of the Cu-S co-doping modified SnO2 in the process of preparing the formic acid by the reduction of the CO2 is reduced to 130 mV vs. RHE.

The invention belongs to the field of electrochemistry catalytic materials, and particularly relates to a non-noble metal-based water-electrolysis oxygen evolution reaction electrocatalyst. The electrocatalyst is a ferronickel layered double-hydroxide oxide loaded with ferric oxyhydroxide nanoclusters. By means of the electrocatalyst, the problems that in the prior art, operation is complex, the steps are tedious and numerous, the catalytic activity is not high, and the energy conversion efficiency is not high are solved; through a solid ferric source slowly releasing ferric ions, a kinetic process of reaction is controlled, and a composite material loaded with the FeOOH nanoclusters is formed by the ferric ions and nickle ions dissolved in water together.

The invention discloses a lithium-oxygen/air cell and a preparation method thereof. A positive electrode catalyst material MNx is used, wherein M is first main group metal, such as lithium, sodium orpotassium, N is carbon or silicon, and x is not more than 100 and more than 6. According to the preparation method, the common commercial materials are used as a basis, and the MNx material is synthesized in situ with the aid of a cell reaction to serve as a positive electrode catalyst, so that the overpotential during charging and discharging processes is effectively reduced, and the running stability of the cell is greatly improved. Furthermore, the lithium-oxygen/air cell provided by the invention adopts an in-situ assembly method, namely after the lithium embedding modification is performed on the original carbon electrode, the carbon electrode is directly used as the positive electrode of the metal-oxygen/air cell without re-assembly, so that the electrode plate is prevented from being secondarily damaged during disassembly, the electrolyte balance does not need to be re-built, the acquired cell power efficiency is higher, the running stability is better, and the good economic prospect and practical value are showed.

The invention relates to a tripetaloid tungsten sulfide nano-sphere, a preparation method and an application of the nano-sphere. The preparation method includes the steps: (a) dissolving tungstate and thiourea in water to form mixed solution; (b) placing the mixed solution in a high-pressure autoclave, performing hydrothermal reaction at the temperature of 220-250 DEG C, and centrifuging, washing and drying the mixed solution. The weight ratio of the tungstate to the thiourea is 4.2:(1.3-5.3). The preparation process is simple, needed equipment is conventional, raw materials are rich, the price is low, a petal-shaped tungsten sulfide nano electro-catalyst is synthesized at low cost, the prepared petal-shaped tungsten sulfide catalyst has good electro-catalytic stability, and stable electro-catalytic hydrogen evolution activity is still kept after circulation is performed for 40000 seconds.

The invention provides a transition metal sulfide/carbon nanotube composite material. A preparation method of the transition metal sulfide/carbon nanotube composite material comprises the following steps: adding carbon nanotubes to a solvent, forming a suspension by ultrasonic treatment; dropping the suspension on the surface of a pretreated glassy carbon electrode; naturally airing to form a uniform thin layer of carbon nanotubes, to obtain a carbon nanotube-modified glassy carbon electrode; adding thiourea and transition metal salt to deionized water; adjusting pH to 0-13 to obtain an electroplating solution; placing the carbon nanotube-modified glassy carbon electrode in the electroplating solution for electroplating to obtain the glassy carbon electrode covered with a transition metal sulfide/carbon nanotube composite material; washing with water and drying naturally; scraping the transition metal sulfide/carbon nanotube composite material from the surface of the glassy carbon electrode. The preparation method provided by the invention is simple in operation and easy in mass production; the prepared composite material has great advantages in catalytic oxygen evolution and energy conversion, and can be used as a catalyst for photo and electro-catalytic oxygen evolution reaction.

The invention discloses a water-based rechargeable zinc ion battery alloy type negative electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: electrochemically depositing a particle layer of a specific metal simple substance on a current collector, then performing heating to 50-450 DEG C under a vacuum condition, and treatingfor 0.1-5 hours; wherein the current collector is carbon cloth, carbon fiber paper, graphene paper, MXene, stainless steel foil or titanium foil, and the metal simple substance is antimony, cobalt, nickel, germanium, copper, silver or gold. The material prepared by the invention can be used as a dendritic-crystal-free alloy type negative electrode material and has high theoretical specific capacity; and the deposited metals can be used as nucleation seeds to effectively inhibit zinc dendrites, and the electrode material can reduce nucleation barriers, reduce nucleation overpotential, realizeuniform zinc deposition, effectively inhibit growth of the zinc dendrites and better exert the cycle stability of the zinc dendrites.

The invention relates to a photo-cured solid state composite electrolyte and a preparation method thereof, and belongs to the technical field of alkali metal batteries. The electrolyte is prepared byuniformly mixing a polymer prepolymer, a photoinitiator, an inorganic solid electrolyte, a salt and an ionic liquid in a light shielding condition, and then carrying out ultraviolet curing under an inert atmosphere. The electrolyte has gradient distribution characteristics due to the gravity sedimentation effect of the inorganic solid state electrolyte in the preparation process, so that the defect that the PEO is directly contacted with the positive electrode and is easy to oxidize can be solved; meanwhile, the metal ion distribution of the surface of the battery electrolyte and the surface of the metal negative electrode can be adjusted, high compatibility of the alkali metal negative electrode and the positive electrode is achieved, and relatively low over-potential and long-term cycling stability in the constant-current polarization can be shown; the impedance of the electrolyte and the electrode interface is relatively small, and the impedance is almost not increased along with the increase of the storage time of the battery; and the method has the advantages that the preparation process is simple, the conventional equipment is used, the raw materials are easy to obtain, the method is safe and pollution-free, and the method is suitable for large-scale batch production.

The invention discloses a monatomic dispersed MXene material and applications in lithium battery negative electrodes. The monatomic dispersed MXene material is characterized in that single doped metalatoms are dispersed on the surface of the sheet layer of the monoatomic dispersed MXene material, and can realize controllable nucleation growth of metal lithium in an initial metal lithium deposition stage; lithium tends to nucleate uniformly on the MXene layer containing single doped atoms, originates from a large number of doped metal atoms, and then grows vertically along the nucleation position due to a strong electric field at the edge so as to form bowl-shaped lithium and even blocky lithium, so that the growth of lithium dendrites is avoided; and when the monatomic dispersed MXene material is used as a metal lithium negative electrode, the monatomic dispersed MXene material is a dendrite-free metal lithium negative electrode, and the negative electrode has low overpotential, longcycle life and deep dissolution deposition plating performance. According to the invention, based on mature roll-to-roll and spraying technologies, the metal lithium negative electrode can be easily expanded in scale so as to substantially benefit the development of lithium batteries in the future.

The invention relates to a method for hydrogen production and storage through catalysis of water splitting by an MOF (metal-organic framework) composite electrode. The method utilizes the unsaturated metal sites and the porous structure of MOF to conduct electrocatalysis on water splitting so as to produce hydrogen, and the produced hydrogen is stored in an MOF porous material on line, thus realizing integration of hydrogen production and storage. The method greatly reduces the hydrogen production overpotential, is simple in operation and is easy to control, storage and release of hydrogen are realized through charge and discharge, the absorption and desorption conditions are mild, the current efficiency is greater than or equal to 75%, and the electrochemical hydrogen storage capacity can reach 920mAh/g. The method provided by the invention realizes synchronization of hydrogen production and storage, and greatly promotes the research and industrialization process of the water splitting technology for hydrogen production and storage.

The invention provides a preparation method of a transitional metal/nitrogen co-doped hollow carbon nano material and an application method thereof. The preparation method comprises the following steps: preparing a cathodic oxygen reduction reaction catalyst for a fuel battery by taking a surfactant as a soft template; first, synthesizing a hollow polymer precursor by means of self assembly of thetemplate in a hydrothermal process and strong interaction between the template and a carbon source precursor; then doping transitional metals and heteroatoms through an oil bath and full grinding; and finally, putting the reactant in a program control tubular furnace, carrying out carbonizing at a high temperature in an inert atmosphere at 600-900 DEG C to obtain the transitional metal/nitrogen co-doped hollow carbon nano material. The transitional metal/nitrogen co-doped hollow carbon nano material prepared by the method has a relatively high specific surface area, good conductivity and sufficient active site and shows excellent electrocatalytic activity, good stability and methanol poisoning resistance to oxygen reduction reaction. The preparation method is low in cost and simple in process, has certain universality, and has certain guiding meaning in synthesizing the cathodic oxygen reduction reaction catalyst for the fuel battery.

The invention relates to the technical field of a modern battery, in particular to a preparation method of a thin-layer lithium-based negative electrode. A negative electrode takes a copper foil current collector as a substrate, a single-layer graphene thin film is synthesized on a surface of the copper foil current collector by a chemical vapor deposition method, graphene/copper used as the negative electrode and a lithium-rich material or a lithium salt of a lithium source used as a positive electrode are assembled to form an electrolytic tank, an electrolyte is injected, the electrolytic tank is sealed, electro-deposition with relatively low current density is performed, the electrolytic tank is disassembled after appropriate reaction time, and the lithium-based negative electrode plated with uniform thin-layer metal lithium can be obtained at a negative electrode part. With the adoption of the method disclosed by the invention, uniform deposition of metal lithium can be achieved, meanwhile, the problem that a large amount of lithium dendrites are generated caused by direct deposition on a surface of the copper current collector is solved, so that a lithium negative electrode material with more safety and stability is obtained and is applied to a lithium primary battery and a lithium secondary battery.

The invention discloses a preparation method and application of a VN@WN nanoparticle with an electrocatalysis function. The preparation method comprises the following steps: firstly, grinding a mixture of dicyandiamide, ammonium metavanadate and phosphotungstic acid, carrying out sieving with a 60-mesh sieve to obtain a mixture, putting the mixture into a porcelain boat, putting the porcelain boatinto a tubular atmosphere furnace, and respectively placing two furnace plugs at the two ends of a tube at an interval of 5 cm; introducing inert gas into the tubular atmosphere furnace to exhaust air in the tube, controlling the inner air pressure of the tube to be -1 MPa to 0 MPa, heating the tube to 700 DEG C to 900 DEG C at a heating rate of 10 DEG C/min, and maintaining the tube at the temperature for 120 min to 180 min; and carrying out cooling to obtain a sample and grinding the cooled sample in a mortar to obtain the VN@WN nanoparticle. The VN@WN nanoparticle with the electrocatalysisfunction prepared by using the preparation method is applied to the enhancement of hydrogen production activity. The VN@WN nanoparticle prepared by the method has an electrocatalytic function, can provide a clean and sustainable energy source for electrolysis of water, and is capable of eliminating the obstacle that a high-cost platinum-based material is widely applied to the industry. The electrocatalyst is simple in preparation process, good in hydrogen production performance and good in stability and circularity.

The invention discloses a gel polymer electrolyte composite membrane and a preparation method and application thereof. The preparation method of the gel polymer electrolyte composite membrane comprises the following steps of: forming a metal organic framework material interface layer on one side, with a compact pore structure, of the polymer base membrane by adopting an interface in-situ polymerization method so as to obtain a polymer composite membrane; and carrying out contact gelatinization on the polymer composite membrane and a plasticizer to form the gel polymer electrolyte composite membrane. The invention provides a novel method for preparing a polymer base membrane by combining freeze casting and phase inversion, which is efficient, convenient and high in controllability; the gelpolymer electrolyte composite membrane prepared by the invention has excellent lithium ion transport capability; and meanwhile, compared with a traditional electrolyte battery, a metal lithium batterywith the gel polymer electrolyte composite membrane has more excellent specific capacity, longer cycle life and higher coulombic efficiency.

The invention belongs to the technical field of electrocatalysis of hydrogen evolution, and discloses a core-shell CoS2@NG nanometer composite material with high performance, low cost, rich resources and excellent electrocatalytic performance of hydrogen evolution, and preparation and application thereof. The preparation method provided by the invention comprises the following steps: subjecting a growth solution of CoS2 to a hydrothermal process so as to obtain core-shell CoS2 nanoparticles; then mixing the core-shell CoS2 nanoparticles with APS in a solvent, and carrying out stirring so as to obtain APS-modified core-shell CoS2 nanoparticles; and placing the APS-modified core-shell CoS2 nanoparticles in a nitrogen doped graphene oxide precursor solution, and carrying out a hydrothermal process so as to obtain the composite material, wherein the precursor solution is composed of the following components: graphene oxide, ammonia water and sodium hydroxide. The composite material provided by the invention has good mechanical flexibility, excellent electrocatalytic performance, electrocatalytic activity of hydrogen evolution and stability, shows low onset potential, low overpotential and high cycling stability, can be applied to the field of electrocatalytic activity of hydrogen evolution, and provides a solution method for the problem of electrocatalysis of hydrogen evolution in the prior art.

The invention discloses a porous hollow RuP@PNC catalyst and a preparing method and application thereof. According to the preparing process of the porous hollow RuP@PNC catalyst, ferric salt, ruthenium salt, phosphide, nitride, carbide and a pore-foaming agent are dissolved in water, after even stirring and mixing are conducted, water in mixed liquid is completely evaporated, a solid product is obtained and ground uniformly, then, roasting is conducted at the nitrogen atmosphere, a product obtained after roasting is arranged in a hydrochloric acid water solution, accordingly, the iron elementin the product can be dissolved and removed, a part of the product is hollow, the product is taken out of the hydrochloric acid water solution to be dried, and the porous hollow RuP@PNC catalyst is obtained. According to the porous hollow RuP@PNC catalyst, the phosphide is formed through phosphorus doping and ruthenium, the charge structure between the phosphorus and the ruthenium is changed through mutual combination of the phosphorus and the ruthenium, a part of the catalyst is hollow through removal of the iron element, the active site of metal is increased, the charge transfer situation between the elements is changed, and accordingly the hydrogen evolution reaction performance of the catalyst is improved.

The invention belongs to the technical field of hydrogen evolution electrocatalysis and discloses an iron disulfide/nitrogen-doped graphene nanocomposite, preparation and application. A preparation method includes the following steps that an iron disulfide precursor solution is mixed with graphene oxide, a hydrothermal method reaction is carried out, and the iron disulfide/nitrogen-doped graphene nanocomposite is obtained. L-cysteine is adopted as a sulfur source and a reducing agent, ammonia water serves as a nitrogen source, ferric acetylacetonate serves as iron salt, a FeS2 nanocube is subjected to homogeneous nucleation growth on an NG surface through a hydrothermal method, and the FeS2/NG nanocomposite is obtained, wherein the nitrogen content ranges from 0.38 wt% to 1.12 wt%; and by means of good hydrogen evolution electrocatalysis performance of iron disulfide and high specific surface area and high conductivity of nitrogen-doped grapheme, a good electrocatalysis hydrolysis hydrogen production effect is shown, and the nanocomposite can be applied to the field of hydrogen evolution electrocatalysis, especially preparation of hydrogen evolution electrocatalysis materials and can be directly used as an electrode material for electrocatalysis hydrolysis hydrogen production.

The invention discloses a phosphorus-containing compound, and a preparation method and an application thereof, and belongs to the fields of material science and technology and chemistry. The phosphorus-containing compound is prepared from cheap raw materials through the simple method; the method is essentially characterized in that the compound is prepared from metal ions and a phosphorus source under the illumination condition of a photoactive material; and the temperature in the prior art is more than 100 DEG C, and the method in the invention is a normal temperature synthesis process, so the obtained compound has a weak crystallization degree. The phosphorus-containing compound has a high photocatalytic activity as a conventional catalyst and a photocatalytic reaction cocatalyst, and achieves a high hydrogen production rate for a photocatalytic hydrogen production reaction. The method and the phosphorus-containing compound can be used for producing an electrode and producing a battery, so the production cost of the electrode and the battery is reduced, the preparation method is simplified, and the obtained electrode is a non-noble metal catalyst, and has the advantages of low cost, low overpotential, high stability and certain industrial application values.