A method for reacting a reaction object with a liquid containing the reaction object in contact with a granular porous body. The upper limit D (mm) of the particle diameter of the granular porous body is determined from D=0.556×LN (T)+0.166 in a column flow method in non-circulation type, and determined from D=0.0315×T+0.470 in the column flow method in a circulation type and a shaking method. The granular porous body includes a skeleton body including an inorganic compound having a three-dimensional continuous network structure, and has a two-step hierarchical porous structure including through-holes formed in voids in the skeleton body, and pores extending from a surface to an inside of the skeleton body and dispersed on the surface. A functional group having affinity with the metal ion is chemically modified on a surface of the granular porous body.

A method for reacting a reaction object with a liquid containing the reaction object in contact with a granular porous body. The upper limit D (mm) of the particle diameter of the granular porous body is determined from D=0.556×LN (T)+0.166 in a column flow method in non-circulation type, and determined from D=0.0315×T+0.470 in the column flow method in a circulation type and a shaking method. The granular porous body includes a skeleton body including an inorganic compound having a three-dimensional continuous network structure, and has a two-step hierarchical porous structure including through-holes formed in voids in the skeleton body, and pores extending from a surface to an inside of the skeleton body and dispersed on the surface. A functional group having affinity with the metal ion is chemically modified on a surface of the granular porous body.

In an amorphous complex metal oxide and a method for producing the same of the present disclosure, the amorphous complex metal oxide is a three-components metal oxide containing titanium (Ti), cerium (Ce), and zirconium (Zr), wherein the amorphous complex metal oxide is amorphous.

A co-assembly method for synthesizing inverse photonic structures is described. The method includes combining an onium compound with a sol-gel precursor to form metal oxide (MO) nanocrystals, where each MO nanocrystal has crystalline and amorphous content. The MO nanocrystals are combined with templating particles to form a suspension. A solvent is evaporated from the suspension to form an intermediate or compound product, which then undergoes calcination to produce an inverse structure.

A co-assembly method for synthesizing inverse photonic structures is described. The method includes combining an onium compound with a sol-gel precursor to form metal oxide (MO) nanocrystals, where each MO nanocrystal has crystalline and amorphous content. The MO nanocrystals are combined with templating particles to form a suspension. A solvent is evaporated from the suspension to form an intermediate or compound product, which then undergoes calcination to produce an inverse structure.

A process for producing a particulate TiO.sub.2 includes supplementing metatitanic acid with an alkali compound in a quantity of 1200 ppm to 2400 ppm of alkali, with a phosphorus compound in a quantity of 0.1 wt.-% to 0.3 wt.-% by weight of P, expressed as phosphorus, and with an aluminum compound in a quantity of 1 ppm to 1000 ppm of Al, expressed as Al, to obtain a mixture. The quantity of the alkali compound, of the phosphorus compound, and of the aluminum compound are with respect to the TiO.sub.2 content. The mixture is calcined at a constant temperature of 940° C. to 1020° C. until a numerical fraction X.sub.50 of TiO.sub.2 has a primary crystallite size of at least 200 nm, to obtain a calcined mixture. The calcined mixture is cooled to obtain a cooled calcined mixture. The cooled calcined mixture is grinded to obtain the particulate TiO.sub.2.

A process for producing a particulate TiO.sub.2 includes supplementing metatitanic acid with an alkali compound in a quantity of 1200 ppm to 2400 ppm of alkali, with a phosphorus compound in a quantity of 0.1 wt.-% to 0.3 wt.-% by weight of P, expressed as phosphorus, and with an aluminum compound in a quantity of 1 ppm to 1000 ppm of Al, expressed as Al, to obtain a mixture. The quantity of the alkali compound, of the phosphorus compound, and of the aluminum compound are with respect to the TiO.sub.2 content. The mixture is calcined at a constant temperature of 940° C. to 1020° C. until a numerical fraction X.sub.50 of TiO.sub.2 has a primary crystallite size of at least 200 nm, to obtain a calcined mixture. The calcined mixture is cooled to obtain a cooled calcined mixture. The cooled calcined mixture is grinded to obtain the particulate TiO.sub.2.

The resistive material for sensing current contains: metal particles selected from a group consisting of nichrome, copper-manganese, and copper-nickel; insulating particles selected from a group consisting of alumina, aluminum nitride, silicon nitride, and zirconia; and titanium oxide.

A preparation method of photo catalyst by transition metal halide molten salt and use thereof, wherein low-valence titanium complexes stable in air and water are used as a Ti source, transition metal halide is used as molten salt, mixing the Ti source and the molten salt as per a certain mole ratio and grinding, heating at air atmosphere until no lower than a fusion point of the molten salt, keeping the molten salt in a state of melting, maintaining the temperature, washing with water, and reduced TiO.sub.2−x rich in Ti.sup.3+ and Ov is obtained in one-step melting reaction. Deficiencies that multiple steps are involved for preparing conventional defect titanium dioxide or use of inflammable and explosive reducing gases or other dangerous reducing agents or oxidizing agents have been addressed; and the defect that the Ti source is liable to be dissolved in organic and other solvents is fully avoided.

A functional element includes functional titanium oxide. The functional titanium oxide includes crystal grains of one or more of β-phase trititanium pentoxide (β-Ti.sub.3O.sub.5) and λ-phase trititanium pentoxide (λ-Ti.sub.3O.sub.5). The functional titanium oxide includes the property that at least a portion of crystal grains of one or more of β-phase trititanium pentoxide (β-Ti.sub.3O.sub.5) and λ-phase trititanium pentoxide (λ-Ti.sub.3O.sub.5) changes into crystal grains of titanium oxide (TiO.sub.2) when the functional titanium oxide is heated to 350° C. or higher.