230 results about "Nickel ferrite" patented technology

The invention provides preparation of a magnetic heterogeneous light Fenton catalyst. The preparation comprises the following steps of: preparing mixed solution by using ferric trichloride and nickel sulfate as raw materials, and performing heating, separation, washing and drying on the mixed solution to obtain the magnetic heterogeneous light Fenton catalyst NiFe2O4. The invention also provides a method for degrading organic pollutants by using the magnetic heterogeneous light Fenton catalyst. The method for degrading the organic pollutants comprises the following steps of: placing organic pollutant solution into a reaction container; adding a proper amount of oxalic acid into the reaction container; adding a proper amount of magnetic heterogeneous light Fenton catalyst into the reactioncontainer; and performing photocatalysis reaction under the irradiation of visible ultraviolet light. The magnetic heterogeneous light Fenton catalyst NiFe2O4 improves the utilization rate of sunlight; and the magnetic heterogeneous light Fenton catalyst has good effect on nickel ferrite photocatalysis of the organic pollutants and high degradation rate.

A process for preparing the magnetically separable composite photo-catalyst includes such steps as synthesizing the nickel ferrite nano-particles as magnetic carrier by low-temp catalytic phase transfer method, liquid-phase depositing SiO2 nano-particles on the surface of nickel ferrite nano-particle, and coating TiO2 nano-particles. Its granularity is less than 15 nm, providing huge surface area.

The invention discloses a reduced graphene oxide / multi-walled carbon nanotube / nickel ferrite (RGO / MWCNTs / NiFe2O4) three-element nano composite wave-absorbing material and a preparation method thereof.The RGO / MWCNTs / NiFe2O4 three-element nano composite material with a local three-dimensional conducting network structure is prepared by adopting graphene oxide (GO), the multi-walled carbon nanotube,nickel nitrate hexahydrate and iron nitrate nonahydrate as precursors and carrying out one-step hydrothermal reaction. The preparation method is pollution-free and environmentally friendly, has no production of any toxic and harmful side products, and is simple in preparation process and low in cost; the prepared three-element nano composite wave-absorbing material is strong in capability of absorbing electromagnetic waves, wide in absorbing frequency band, small in thickness and low in density, can realize effective absorption of the electromagnetic waves with different wavebands by adjusting the content of MWCNTs in the composite material and the thickness of a coating layer, and has an important application value in the fields of electromagnetic absorption and electromagnetic shielding.

The invention discloses a modification method of a nickel ferrite negative electrode material. The method comprises the steps of firstly synthesizing a NiFe2O4 / graphene composite material, carrying out carbonizing treatment at a high temperature, and evenly coating the surface of the NiFe2O4 / graphene composite material with a carbon layer. According to the material obtained through the modification method, the initial discharge capacity is greater than 1237mAh / g and the capacity retention ratio after 100 cycles is greater than 96%. Therefore, according to the modification method, the conductivity of the material is improved, the reversibility in charge and discharge processes is improved and the cycle performance of the material is improved.

The invention is a nano magnetic silicon ball preparing method, applicable to the fields of chemical engineering, environmental protection and biomedicine, firstly selecting bivalent iron salt as catalyst, and by low temperature catalytic phase conversion method, catalytically converting bivalent nickel salt and trivalent iron salt into magnetic nickel ferrite nano particles, dispersing them into reverse micelle solution under the action of surface active agent, coating SiO2 on them by gelatination to form nano magnetic silicon balls, 50nm-sized , where the mass ratio of nickel ferrite nano particle to SiO2 coating is less than 10. And it provides huge surface area for loading of active components in different application fields. And loading TiO2 photocatalyst on the nano magnetic silicon balls can make magnetically separable photocatalyst, able to be effectively used for water treatment.

The invention relates to a preparation method of an ultrathin paper-base wave-absorbing material, belonging to the technical field of electromagnetic shielding. The preparation method comprises the following steps: acidifying a multi-walled carbon nanotube which serves as a carrier by virtue of concentrated nitric acid to generate oxygen-containing groups on the surface of the carbon nanotube so as to provide depositing sites for cobalt-nickel-iron ions; carrying out hydrothermal reaction to uniformly embed cobalt-nickel ferrite nano-particles into the carbon nanotube by virtue of an electrostatic attraction effect between the metal ions and the oxygen-containing groups so as to effectively improve electromagnetic performance and generate a cobalt-nickel ferrite / carbon nanotube with a good wave-absorbing effect; and finally, dispersing the cobalt-nickel ferrite / carbon nanotube and regenerated paper fibers into a turbid liquid in a high-speed shearing dispersion machine, manufacturing wet paper with pulp, carrying out compaction to remove moisture, flatting a paper web, drying, and carrying out press polishing to increase the smoothness of the paper so as to obtain the ultrathin paper-base wave-absorbing material. The ultrathin paper-base wave-absorbing material has good electromagnetic matching property, is capable of effectively absorbing and inhibiting secondarily-emitted noise waves and has high high-frequency electromagnetic wave shielding performance.

The invention discloses a nitrogen-doped graphene nickel ferrite composite wave-absorbing material and a preparation method thereof. A nitrogen-doped reduced graphene oxide / hexagonal nickel ferrite nano composite material is prepared by taking graphene oxide (GO) as a template, taking ferric nitrate nonahydrate and nickel nitrate hexahydrate as precursors and taking hydrazine hydrate as a nitrogen-doped reagent through a simple one-step hydrothermal method. The nano composite material prepared by the invention is formed by entangling a large number of hexagonal nickel ferrite particles in nanosize by two-dimensional folded graphene, has strong electromagnetic wave absorption capability, wide absorption frequency band and small matching thickness, and can generate double absorption peaks at low frequency (3-6GHz) and high frequency (12-18GHz); and the nitrogen doping amount of graphene in the composite material can be changed by controlling the adding volume of hydrazine hydrate, meanwhile, effective attenuation of the composite material to electromagnetic waves under different wave bands can be achieved by changing the matching thickness, and the composite material has important application value in the fields of electromagnetic wave absorption and electromagnetic shielding.

The invention relates to a high tenacity non-nickel ferrite stainless steel. The components has the mass percentage that: C occupies 0.03 to 0.08 percent, Si is lower than or equal to 1.0 percent, Mn is lower than or equal to 1.0 percent , S is lower than or equal to 0.030 percent , P is lower than or equal to 0.035 percent, Cr occupies 16 to 21 percent, N occupies 0.01 to 0.03 percent, is lower than or equal to 0.0050 percent, rear earth RE occupies 0.02 to 0.1 percent, and the residual is Fe and inevitable foreign impurities. The utility model provides a manufacture method that: firstly, smelting and casting are performed, the time between the adding of rear earth metal and the steel casting is strictly controlled to be lower than or equal to 25 seconds; the casting temperature is controlled at 1550 plus or minus 5 DEG C; secondly, casting ingot or casting blank cogging is performed, the casting ingot or the casting blank can adopt forging cogging or continuous casting continuous rolling, the heating temperature of the casting ingot or the casting blank is 1150 plus or minus 10 DEG C, and the final forging temperature is not lower than 900 DEG C, and the casting ingot or the casting blank is performed with water cooling. thirdly, steel material rolling is performed, the heating temperature is 1160 plus or minus 10 DEG C, the rolling starting temperature is controlled between 1100 to 1150 DEG C, and the final rolling temperature is controlled to be lower than or equal to 800 DEG C, and the casting ingot or the casting blank is performed air cooling; finally, heat treatment is performed. The invention can obviously lengthen the service life under the low temperature condition, and compared with ultra low carbon and nitrogen and nickel-bearing ferrite stainless steel, the performance-price ratio is high.