3545 results about "Transition metal" patented technology

The invention discloses a synthetic method of a water soluble ultraviolet light absorber BP-9. The method mainly comprises the following process steps: (1) carrying out methylation on the main raw materials of 2, 2', 4, 4'-tetrahydroxyl benzophenone, a transition metal salt catalyst and a mixed solvent which is prepared from dichloroethane and anhydrous ethanol in equal parts by weight to obtain 2, 2'-dihydroxyl-4, 4'-dimethoxyl benzophenone; (2) carrying out sulfonation reaction on the main raw materials of methylate, sulfamic acid and C1-C3 halohydrocarbon to obtain 2, 2'-dihydroxyl-4, 4'-dimethoxyl benzophenone-5, 5'-disulfonic acid; and (3) carrying out neutral reaction on the main raw materials of sulfonated product, inorganic base and ethanol water to finally obtain the BP-9 product. The synthetic method disclosed by the invention is few in reaction step, low in cost, high in product purity and stable in quality, and raw materials are easily available.

Disclosed in the present invention are a biomass-derived graded porous asymmetric coordination monatomic carbon-based electrocatalyst, and a preparation method therefor and the use thereof. The preparation method for the biomass-derived graded porous asymmetric coordination monatomic carbon-based electrocatalyst comprises the following steps: (1) stirring and mixing de-alkalized lignin with a transition metal salt, a nitrogen-containing compound and a template, i.e., magnesium oxide, in a solvent until uniform, so as to obtain a suspension, wherein the transition metal comprises iron and zinc; (2) heating, evaporating and drying off the suspension, so as to obtain a lignin / metal ion / nitrogen-containing compound / template mixed precursor; and (3) subjecting the mixed precursor to high-temperature pyrolysis under the protection of an inert gas, cooling same, and then sequentially washing and drying same, so as to obtain a monatomic carbon-based electrocatalyst. The monatomic carbon-based electrocatalyst provided in the present invention has graded pores of micropores, mesopores and macropores, a surface nanosheet and an asymmetric coordination structure of Fe-N3O at the same time, and can be applied to fuel cells and metal-air cells.

The invention provides a preparation method of a cobalt-based bimetallic alloy positive electrode lithium supplement composite material and an application technology of the cobalt-based bimetallic alloy positive electrode lithium supplement composite material in a battery. The lithium-supplementing composite material is a lithium salt, a cobalt-based bimetallic alloy catalyst for promoting low-pressure decomposition of the lithium salt, and a positive electrode material. The lithium salt is lithium oxalate, the cobalt-based bimetallic alloy catalyst is prepared from nitrogen and sulfur co-doped carbon impregnated in a transition metal salt solution through freeze drying and high-temperature calcination, and the positive electrode material comprises one of lithium iron phosphate, lithium cobalt oxide and ternary high nickel (LiMO2, M = Ni, Co and Mn). When the lithium supplement agent is applied to a secondary lithium ion battery, the decomposition voltage of the lithium supplement agent can be reduced, the irreversible loss of capacity is reduced, and the initial coulombic efficiency is improved.

The invention discloses a P2-phase sodium ion positive electrode material with a superlattice ordered structure and a preparation method of the P2-phase sodium ion positive electrode material. The chemical formula of the P2-phase sodium ion positive electrode material is Na < x > M < 1-a-b > A B O < 2 >, wherein M is a transition metal element Mn or / and Ni; a doping sites are transition metal vacancies, and / or doped metal elements Mg and / or doped metal elements Li; the doping site of B is doped with a transition metal element Fe or doped with a transition metal element Cu or doped with a transition metal element Zn; 0.8 < = x < = 0.9, 0.25 < = a, 0.04 < = b < = 0.09. According to the P2 type material with the superlattice ordered structure, the layered structure stability and the sodium ion transmission efficiency of the material can be remarkably improved, so that the problems of poor structure stability and low ion diffusion rate of a traditional sodium ion positive electrode material are effectively solved; the P2 type material with the superlattice ordered structure can be suitable for preparing a sodium ion battery system with high energy density.

A ternary positive electrode material modified with a glassy metal-organic framework, and a preparation method therefor and the use thereof. The ternary positive electrode material modified with a glassy metal-organic framework is obtained by grinding and mixing a ternary positive electrode material and a metal-organic framework, and then subjecting same to a melt quenching treatment under a protective atmosphere. Forming a crack-free glassy metal-organic framework containing nano / sub-nano pores on a surface of the ternary positive electrode material can significantly improve the stability of the ternary positive material, alleviate the dissolution of transition metals, and ultimately improve the electrochemical performance of batteries and prolong the service life of the batteries.

The invention relates to the field of electro-catalytic materials, and particularly discloses a layered transition metal hydroxide catalyst as well as a macro-quantity preparation method and application thereof. According to the method, the nanoparticles are formed through solvent difference induction, the nanoparticles are adsorbed on the foamed nickel substrate, formation of the layered transition metal hydroxide on the foamed nickel substrate is promoted, the layered transition metal hydroxide is prepared through a heterogeneous nucleation mechanism, and compared with a traditional homogeneous nucleation process, disordered aggregation of the nanoparticles can be effectively prevented; the preparation method has the advantages of high dispersity and uniform structure, the preparation method does not depend on conditions such as high temperature and high pressure, the equipment cost, energy consumption and safety risk can be reduced, and the method has universality and environmental friendliness and can be applied to macroscopic preparation of the catalyst with good uniformity.

The invention provides an ultrahigh-temperature ceramic precursor, a preparation method thereof, a modified high-performance inorganic fiber and application, and relates to the technical field of high-temperature-resistant materials. The preparation of the ultra-high-temperature ceramic precursor comprises the following steps: placing a transition metal compound mixed solution in a low-temperature environment, standing, adding a coordination agent and an exchange agent, reacting, filtering in a low-temperature nitrogen atmosphere, adding a mixed solvent into the filtrate, heating and refluxing, and carrying out a polymerization reaction to obtain the ultra-high-temperature ceramic precursor. The superhigh-temperature ceramic precursor provided by the invention forms a high-temperature protective coating on the surface of a high-performance inorganic fiber and other materials, and meanwhile, a transition metal ion solution is placed under a low-temperature condition through a metal ion stabilization method, so that the internal structure of transition metal ions is more stable, and uniform dispersion at a molecular level is achieved; and the uniformity of the elements can be kept in the curing and cracking processes, and the phenomenon of coating stripping caused by mismatching of thermal shrinkage coefficients of a coating and a substrate material in an extreme environment is avoided.

Some variations provide a photochromic heterostructure comprising: first semiconductor nanoparticles that have an average first-nanoparticle effective diameter from 1 nanometer to 20 nanometers, wherein the first semiconductor nanoparticles are not doped; and second semiconductor nanoparticles that have an average second-nanoparticle effective diameter from 1 nanometer to 60 nanometers, wherein the second semiconductor nanoparticles are doped with one or more transition metals, wherein the second semiconductor nanoparticles have a bandgap energy that is higher than the bandgap energy of the first semiconductor nanoparticles, and wherein the first semiconductor nanoparticles and the second semiconductor nanoparticles are in physical contact with each other. The disclosed photochromic heterostructure is especially useful when lower-energy light excites lower-energy-bandgap first nanoparticles to cause higher-energy-bandgap, doped second nanoparticles to photodarken. If the first nanoparticles were not present, the doped second nanoparticles would require higher-energy light to cause darkening. Examples demonstrate embodiments of the invention.

The present disclosure provides a new wet atomic layer etch (ALE) process for etching high-k dielectric materials. More specifically, the present disclosure provides various embodiments of methods that utilize new etch chemistries for etching transition metal oxide dielectric materials in a cyclic wet ALE process. In the example embodiments provided herein, new etch chemistries and methods are provided for etching zirconium dioxide (ZrO2), hafnium dioxide (HfO2) and HfxZr(1-x)O2 dielectrics in a cyclic wet ALE process. However, the wet ALE techniques described herein are not strictly limited to the example materials discussed herein and can be applied to other transition metals and transition metal oxides.

The invention discloses a positive electrode material formed by compounding polyanionic sodium ferric sulfate and a layered transition metal oxide, and a preparation method and application thereof, and the preparation method comprises the following steps: preparing a sodium ferric sulfate positive electrode material, preparing a layered transition metal oxide positive electrode material, and mechanically mixing the sodium ferric sulfate and the layered transition metal oxide material, the composite material is obtained. The production process of the two materials is easy for large-scale production, has high similarity with the existing battery industrial equipment, is simple in method for compounding the two materials, and has large-scale industrial application value. The composite material has the stability of a polyanionic material and the high energy density of a layered oxide material, and has more excellent comprehensive electrochemical performance.

The invention belongs to the technical field of catalyst preparation, and provides an M2 diatomic site catalyst for a reaction for preparing phenylenediamine through dinitrobenzene hydrogenation and a preparation method and application thereof.The catalyst is formed by anchoring transition metal M diatomic sites to the surface of a diamond-graphene carrier and is prepared by taking nano-diamond powder as a raw material through a one-step reaction. Annealing treatment is carried out at the high temperature of 750-850 DEG C, a diamond-graphene carrier of an sp3 atsp2 core-shell structure is constructed, and the surface defect density of the diamond-graphene carrier is regulated and controlled in the process; and depositing metal species on the surface of the carrier through ALD double-step deposition to obtain the M2 diatomic site catalyst with high density and stable structure. The M2 diatomic site catalyst is applied to a reaction for preparing a corresponding phenylenediamine compound through hydrogenation of a dinitrobenzene compound, and high conversion rate and high selectivity can be achieved with low metal loading capacity under mild conditions. The method can be popularized to construction of diatomic catalysts of various transition metals, and has a wide application prospect.

The present disclosure relates to the extraction of lithium from liquid resources such as natural and synthetic brines, leachate solutions from clays and minerals, and recycled products. Herein are systems and processes for extracting lithium using ion exchange materials, where transition metal impurities may be removed from the synthetic lithium solution. In some embodiments, the transition metal species are reformulated to form ion exchange materials to be used in the systems and processes described herein.

The invention provides a graphene-based hydrogen sulfide gas sensor and a preparation method thereof, and relates to the technical field of gas sensors. The preparation method of the graphene-based hydrogen sulfide gas sensor comprises the following steps: soaking the wood substrate in a mixed metal salt solution containing a water-soluble silver salt and a water-soluble transition metal salt; irradiating the soaked wood substrate by using a laser beam at room temperature under the condition of no shielding gas, so that lignin and cellulose in the wood substrate are cracked and reconstructed to form graphene; meanwhile, the mixed metal salt immersed in the wood substrate is decomposed to form bimetallic oxide nanoparticles including silver oxide nanoparticles and transition metal oxide nanoparticles, and the bimetallic oxide nanoparticles are dispersed on the surface of each layer of graphene to obtain a sensitive layer; and coating conductive materials on the wooden substrate and on the two sides of the sensitive layer to form a connecting electrode in contact with the sensitive layer, thereby obtaining the graphene-based hydrogen sulfide gas sensor.

The invention provides a modified positive electrode material and a preparation method and application thereof. The modified positive electrode material comprises a lithium manganese iron phosphate inner core and a coating layer coating the surface of the lithium manganese iron phosphate inner core, and the material of the coating layer comprises oxyfluoride; ti and S are co-doped in the lithium manganese iron phosphate core. Ti and S are co-doped in a lithium manganese iron phosphate core, Ti doping can introduce additional electron holes to enhance the intrinsic electron conductivity of the material, S doping can expand a lithium ion channel and improve the Li < + > diffusion rate, and the Ti doping and the S doping are synergistically optimized through two channels of electron conduction-ion migration, so that the rate capability and the cycling stability of the positive electrode material are improved; the oxyfluoride is adopted as a coating layer material, so that HF corrosion and dissolution of transition metal can be reduced, an interface side reaction is inhibited, meanwhile, the excellent thermal stability and wide electrochemical window of the oxyfluoride can inhibit decomposition and gas production of an electrolyte in a high-temperature environment, and the thermal stability and electrochemical stability of the modified positive electrode material are improved.

The invention relates to the technical field of environmental protection, and discloses a method for degrading formamide organic wastewater and recycling key metals of a retired lithium ion battery. The method comprises the following steps: S1, obtaining the positive electrode material of the retired lithium ion battery, mixing the positive electrode material with formamide organic wastewater, and carrying out hydrothermal reaction to obtain a leachate; s2, adjusting the pH value of the leachate to 6-14, and carrying out a transition metal precipitation reaction to obtain a transition metal hydroxide precursor and a lithium-rich filtrate; and S3, adding a sodium carbonate solution into the lithium-rich filtrate, carrying out a precipitation reaction, and collecting lithium carbonate. The formamide organic wastewater serves as an endogenous reducing agent, deep degradation of the formamide organic wastewater is achieved under the hydrothermal condition, efficient leaching of key metal in the retired lithium ion battery is achieved, and waste is treated with waste; the formamide degradation efficiency can reach 90% or above, and the defects that an existing formamide wastewater treatment method is high in energy consumption, large in reagent consumption, high in cost, low in degradation efficiency and large in environmental treatment pressure are overcome.

The invention relates to the technical field of high-temperature-resistant composite coatings, in particular to an atomic-scale complex-phase high-entropy oxide coating material and preparation and application thereof. The preparation method comprises the following steps: firstly, dissolving Mg2AlO4 and transition metal alloy powder, mixing, and carrying out ball milling to obtain spinel-structure high-entropy oxide precursor powder; then carrying out freeze drying treatment on the spinel structure high-entropy oxide precursor powder, and then carrying out sintering treatment to obtain spinel structure high-entropy oxide powder; dissolving metal salt, and blending to obtain a mixed solution; and finally, uniformly mixing the spinel-structure high-entropy oxide powder with the mixed solution, carrying out solvothermal reaction, and carrying out post-treatment to obtain the atomic-scale complex-phase high-entropy oxide coating material. The coating material provided by the invention has high-stability infrared radiation performance and can resist high-temperature oxidation.

The invention discloses a supported noble metal catalyst for a wet catalytic oxidation reaction and a preparation process of the supported noble metal catalyst, and belongs to the technical field of catalysts for wastewater treatment. The noble metal catalyst comprises a modified titanium dioxide carrier, transition metal and noble metal, the transition metal and the noble metal are loaded on the modified titanium dioxide carrier, the modified titanium dioxide carrier is modified by adopting rare earth metal, the total loading amount of the noble metal and the transition metal is 0.5-0.7 wt%, and after the titanium dioxide carrier is subjected to rare earth modification, the noble metal and the transition metal are loaded on the modified titanium dioxide carrier. The titanium dioxide carrier transition metal forms stable chemical bonds, precipitation of the transition metal in the use process is reduced, and meanwhile, the transition metal and the noble metal are matched with each other, so that the catalytic activity of the noble metal catalyst is improved.

The invention discloses a method for preparing a sulfur-doped nickel hydroxide-based self-supporting electrolyzed water anode, and belongs to the technical field of preparation of electrolyzed water catalytic electrodes, and the method comprises the following steps: S1, preparing strong oxidizing salt, thiourea and transition metal salt into an active solution; s2, pretreating the nickel-containing metal substrate to obtain a precursor; and S3, immersing the precursor in an active solution for ultrasonic impregnation, and performing in-situ oxidation to prepare the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode. According to the method for preparing the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode, an oxidizing agent-thiourea-transition metal salt synergistic reaction system is adopted, an ultrasonic-assisted technology is combined, and a high-performance catalytic layer is directly grown on the surface of the metal substrate in situ at room temperature; the invention aims to synchronously realize high catalytic activity, excellent stability and macro preparation of the electrode and fundamentally solve the core pain points of long process, high energy consumption, difficulty in amplification and the like in the prior art.

The invention provides a photocatalyst based on sulfide homogeneous heterojunction and a preparation method and application thereof, and belongs to the technical field of photocatalysts. The photocatalyst based on the sulfide homogeneous heterojunction provided by the invention is a heterojunction formed by twin-crystal sulfur-cadmium-manganese and transition metal sulfide, has excellent structural stability, and can provide more photo-induced electrons. Therefore, when the photocatalyst provided by the invention is used for degrading H2S to produce hydrogen, the Schottky junction of the photocatalyst can reduce the hydrogen production overpotential, H2S is effectively decomposed to produce hydrogen, and meanwhile, a product Na2S2O3 with a high additional value is produced. The result of the embodiment shows that the photocatalyst based on the sulfide homogeneous heterojunction has excellent catalytic activity when being used for degrading H2S to produce hydrogen.

Disclosed in the present invention are a precursor for a polyanionic sodium-ion battery positive electrode material and a preparation method therefor. The chemical general formula of the precursor is NaxMyHzOa(POb)c·mH2O, wherein M is a transition metal element Fe and / or Mn. The relationship between x, y, z, a, b, and c is x+3y+z-2a+5c-2b×c=0, and m is greater than or equal to 0. The precursor for the polyanionic sodium-ion battery positive electrode material and the preparation method therefor of the present invention have the characteristics of high phase purity, high compaction density, excellent electrochemical performance, low costs, and wide system applicability.

A modified lithium-rich manganese-based positive electrode material, and a preparation method therefor and the use thereof. The modified lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based positive electrode material, wherein the bulk phase of the lithium-rich manganese-based positive electrode material is doped with a high-valent transition metal element, and the surface phase of the lithium-rich manganese-based positive electrode material has a lithium metal compound coating layer and an oxygen vacancy. In the modified lithium-rich manganese-based positive electrode material, the doping with a bulk-phase high-valence transition metal element, the coating with a surface-phase lithium metal compound coating layer and the construction of an oxygen vacancy are conducted at the same time; and by means of the co-action of the three, the rate capability and the cycling performance of the lithium-rich manganese-based positive electrode material can be significantly improved, which is of great significance for the further commercialization of the lithium-rich manganese-based positive electrode material.

Disclosed herein are methods for producing electrodes comprising single-layer 1T′-transition metal dichalcogenide (TMD) nanosheets. The method includes filtering a suspension of single-layer 1T′-TMD nanosheets over a polymeric substrate to produce the electrode, wherein, the single-layer 1T′-TMD nanosheets of the electrode are no more than 1,000 nm in thickness; the electrode comprises at least 70% 1T′-phase; and the electrode has a calculated electrochemical active surface area (ECSA) that is about 10-fold higher than that of a control electrode, which comprises 2H-TMD nanosheets. Also disclosed herein are methods for deionizing a fluid. The method includes steps of discharging the fluid in an electrochemical capacitor at a constant voltage of no more than 0.5 V to deionize the fluid, wherein the electrochemical capacitor is characterized in having the electrode comprising single-layer 1T′-TMD nanosheets produced by the present method.

The invention relates to the technical field of high-entropy ceramic powder, in particular to diboride high-entropy ceramic powder and a preparation method thereof.The preparation method comprises the following steps that five transition metal oxides, boron powder and fused salt serve as raw materials, are evenly mixed through a mixer and then are dried at the temperature of 60-200 DEG C, and a mixture is obtained; then, the mixture is put into a corundum crucible, and heat preservation is conducted for 1-20 h at the temperature interval of 700-1600 DEG C and under the protective atmosphere; and after the reaction is completed, cooling, washing, carrying out suction filtration, and drying at 60-200 DEG C to finally prepare the diboride high-entropy ceramic powder. The method has the advantages of low synthesis temperature, small product particle size, uniform element distribution, environment friendliness and the like, and the prepared diboride high-entropy ceramic powder shows excellent electromagnetic wave absorption performance.

The invention relates to a porphyrin metal organic framework composite material, a preparation method and a biogenic amine SERS (Surface Enhanced Raman Scattering) array sensor. The preparation method of the composite material comprises the steps that a copper precursor solution is added into a surfactant, heating reaction is conducted, a reducing agent is added, heating reaction is conducted, and copper nanoparticles are obtained; the preparation method comprises the following steps: adding a transition metal salt and a surfactant into an organic solvent, adding a porphyrin ligand, carrying out a solvothermal reaction, carrying out centrifugal separation, washing and drying to obtain a porphyrin metal organic framework material, and dispersing the porphyrin metal organic framework material into the organic solvent to obtain a dispersion liquid A; and dispersing copper nanoparticles in the dispersion liquid A, carrying out a second heating reaction, and carrying out centrifugal separation, washing and drying to obtain the porphyrin metal organic framework composite material. The invention also provides the porphyrin metal organic framework composite material prepared by the preparation method, and the application of the porphyrin metal organic framework composite material as a biogenic amine SERS array sensor. The invention solves the problem that the accuracy of the detection result is influenced because the traditional biogenic amine detection method is difficult to realize field detection.

The invention relates to a high-entropy perovskite material and a preparation method and application thereof, the chemical formula of the high-entropy perovskite material is ABO3, the A-site element is La element, and the B-site element is selected from 5-10 transition metal elements; the high-entropy perovskite material has a two-dimensional Tailing structure, nano-particles are arranged in a cross-linking manner, and gaps are formed among the particles. Compared with the prior art, the two-dimensional Turing structure high-entropy perovskite material is endowed with excellent electro-catalytic water decomposition hydrogen production performance due to unique morphology and components, is adaptive to fluctuation power of clean energy such as wind energy and solar energy, and has a wide industrial application prospect.

The invention provides a neodymium iron boron magnet and a preparation method thereof, and belongs to the technical field of magnetic materials. The neodymium-iron-boron magnet comprises rare earth elements R, transition metal elements T, metal elements M and B elements, the R comprises Pr and Nd, the mass percent of the R is 29-32 wt%, the R comprises heavy rare earth elements Tb and Dy with the mass percent being 0-0.1 wt%, the M at least comprises Ti and Zr, and the sum of the mass percent of Ti and the mass percent of Zr is 0.1-0.6 wt%; t comprises Fe, or Fe and Co; the mass percent of the B is 0.84 wt%-0.94 wt%; the neodymium-iron-boron magnet is provided with a main phase and a grain boundary phase comprising a rare earth-rich phase, the proportion of the rare earth-rich phase to the grain boundary phase is 0.15-0.35, and the atom proportion of Pr in R in the rare earth-rich phase is 0.4-0.5. The neodymium-iron-boron magnet disclosed by the invention has excellent magnetic performance under the condition of no heavy rare earth or low heavy rare earth elements.

The invention discloses a synthesis method of allyl phosphonic acid diester. According to the method, phosphorous acid diester and an allyl chloride compound are used as raw materials and react in the presence of a specific transition metal catalyst and alkali under the conditions of normal pressure and 45-60 DEG C to obtain the allyl phosphonic acid diester. The method has the advantages of mild reaction conditions, simple operation, high product yield (90-99%), no by-product, no generation of halogenated alkane gas and easy industrial production, and is suitable for the fields of polymer flame retardants, electronic materials, pesticide and medicine intermediates and the like.

Disclosed is a phosphate e precursor, which has a chemical formula of LixMy(PO4)(x+y) / 2Az·wH2O, where M is a transition metal element selected from one or more of Fe, Ti, V, Cr, Ni, Co, Mn, Al, Nb, Y, Zr, Sb, Mo, Sn, and Ce, A is one or more of F, OH, CO32−, C2O42−, and O2−; and 0.5≥x<1.2, 0.5<y≥1, 0≥z≥1, and 0.1≥w<8. The phosphate precursor has good uniformity, contains crystal water, and exhibits excellent structural stability, and can be used to prepare olivine-type phosphate cathode material through sintering at a low temperature of 260° C.-600° C.; and the phosphate precursor is blended with a carbon source and is subjected to heat treatment to obtain carbon-contained cathode material, which has good electrochemical properties.

The invention discloses a fused salt phase change heat storage composition as well as a preparation method and application thereof, and belongs to the technical field of heat storage. The fused salt phase change heat storage composition provided by the invention comprises the following components: a fused salt material, the melting point of the fused salt material is 100-1500 DEG C, and the absorption coefficient of the fused salt material to infrared waves is 0-100m <-1 >; the infrared absorbing material comprises at least one of transition metal chlorine salt, metal carbonate, metal sulfate, metal nitrate, a carbon-based material, silicon carbide and spinel. The fused salt phase change heat storage composition provided by the invention has high heat exchange power (average heat release power) and heat storage energy density. The invention further provides a preparation method and application of the fused salt phase change heat storage composition.

The present invention provides a substrate with a coating comprising, in order: a) a substrate; b) a primer layer comprising a first transition metal or an oxide thereof; c) one or more corrosion resistant layers, each layer comprising a first sub-layer, a second sub-layer and a third sub-layer, the sub-layers comprising the first transition metal and a second transition metal, where the ratio of the first transition metal and the second transition metal varies between the sub-layers; d) a conductive layer comprising the second transition metal, or a nitride thereof and / or an oxide thereof. The invention also describes a method for producing such a substrate with a coating. The coated substrate has good electrical conductivity and corrosion resistance.