The present disclosure relates to a method of preparing a zinc ferrite catalyst. More particularly, the present invention relates to a method of preparing a zinc ferrite catalyst comprising a) a step of dissolving a zinc precursor and an iron (III) precursor in water to prepare an aqueous metal precursor solution; b) a step of precipitating a solid catalyst precursor while vaporizing water in the aqueous metal precursor solution; and c) a step of firing the precipitated solid catalyst precursor to prepare a zinc ferrite catalyst. In accordance with the present disclosure, the method of preparing a zinc ferrite catalyst can be simply carried out without a pH adjustment step and can secure reproducibility.

The present invention discloses a process to treat a ferrite based catalyst useful in the oxidative dehydrogenation of monololefins and diolefins which process includes a preheat step prior to use of the catalyst in the OXO-D reactor. The catalyst is preferably a zinc ferrite catalyst for the production of butadiene. It has been observed that substantially no nitrogen oxide emissions result from the use of this treated catalyst in the reactor unit during the oxidative dehydrogenation reaction.

A method of producing one of magnetite and ferrite nanoparticles comprising the step of mixing an iron containing metal chemical with a fatty acid.

A connection structure between a center electrode and a metal terminal of a spark plug having a composite part that contains a plurality of secondary particles each formed of a plurality of primary particles of iron-containing oxide as a magnetic substance, and a conductive material coating the plurality of secondary particles. The iron-containing oxide includes at least one of an oxide represented by M.sub.1+AOFe.sub.2AO.sub.3 (where 0.5A0.5; and M is at least one kind of element selected from the group consisting of Mn, Fe, Co, Ni, Cu, Mg, Zn and Ca) and an oxide represented by Q.sub.3Fe.sub.5O.sub.12 (where Q is at least one kind of element selected from the group consisting of Y, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd and Sm). In cross section, an average particle size of the primary particles is 0.5 m to 100 m, an average particle size of the secondary particles is 0.5 mm to 2.0 mm, and a porosity of the inside of the secondary particles is 5% or lower.

A set of spherical inorganic particles having the particular property of being spontaneously individualized, both in dry state in the form of a powder and when they are dispersed in a matrix. The method for producing the particles, and the materials produced by including the particles in the matrices are also described.

The present invention relates to a process for preparing lutetium-doped zinc-ferrite ceramics for humidity sensor application and its composition thereof. This invention discloses a composition for lutetium-doped zinc ferrite ceramics, optimized for humidity sensor applications. The composition comprises specified weight percentages of zinc nitrate, iron nitrate, lutetium nitrate, glucose, urea, and optional distilled water. A corresponding synthesis process involves stoichiometric mixing, addition of glucose and urea, stirring with distilled water, and subsequent combustion in a preheated furnace. The ratio of lutetium varies from 0.00 to 0.07. The resulting ZnFe.sub.(2-x)Lu.sub.xO.sub.4 nanoparticles exhibit stability and uniformity, confirmed through XRD, FTIR, and SEM analyses. The humidity sensor performance is evaluated, with an optimized Lu=0.05 composition demonstrating a remarkable 93% sensing response. This composition and process offer potential for efficient and stable humidity sensors in various applications.

The present invention relates to a kit for water treatment, comprising: a photocatalyst including at least one of SnFe.sub.2O.sub.4, ZnFe.sub.2O.sub.4, CuFe.sub.2O.sub.4, Fe.sub.3O.sub.4, MnFe.sub.2O.sub.4 and NiFe.sub.2O.sub.4; and an active oxide. The present invention also relates to a method for manufacturing a photocatalyst and a use of the prepared photocatalyst.

Ferrite films, antennas including ferrite films, and methods of making thereof are provided. The methods can include tape casting of a slurry to produce a green film, wherein the slurry includes a ferrite powder, a dispersant, and a binder in a suitable solvent; and densifying the green film to produce the ferrite film having a thickness of 50 m to 5 mm. The methods can be used to make large area films, for example the films can have a lateral area of about 1000 cm.sup.2 to 3000 cm.sup.2. VHF/UHF antennas are including the ferrite films are also provided.

A set of spherical inorganic particles having the particular property of being spontaneously individualized, both in dry state in the form of a powder and when they are dispersed in a matrix. The method for producing the particles, and the materials produced by including the particles in the matrices are also described.

This invention provides a catalyst comprising a new form of ZnFe.sub.2O.sub.4 spinel nanoparticles, and a method for preparing same. The catalyst is useful for catalyzing the esterification of fatty acids or transesterification of triglycerides, wherein the reaction rate and conversion can be enhanced by free fatty acids.