A method is disclosed in which a gas of hydrogen and nitrogen, or hydrogen and ammonia, or hydrogen, nitrogen, and ammonia, is introduced to a fluidized bed. The gas flows through the fluidized bed, and titanium dioxide particles are introduced to the fluidized bed to form a fluid mixture of the particles and gas in the fluidized bed. The particles are reacted with the gas in the fluid mixture to form particles including titanium dioxide and nitrogen. The particles can be disposed along an air flow path in operative communication with a light source for air treatment.

The present invention provides a nanostructured titanic acid salt and a preparation process and use thereof. The process comprises preparing a dispersion containing titanium peroxy complex; slowly adding a metal compound to the dispersion containing the titanium peroxy complex to form a solution; adding an alcohol to the solution under normal temperature and normal pressure to produce the nanostructured titanic acid salt precursor precipitate in the solution, and separating the precipitate to obtain the titanic acid salt precursor; drying the precursor, and then heat treating it to obtain the nanostructured titanic acid salt product. The present invention provides a process for preparing a titanic acid salt with simple preparation process, easy control for process parameters and easy large-scale industrial production.

The present invention provides a nanostructured titanic acid salt and a preparation process and use thereof. The process comprises preparing a dispersion containing titanium peroxy complex; slowly adding a metal compound to the dispersion containing the titanium peroxy complex to form a solution; adding an alcohol to the solution under normal temperature and normal pressure to produce the nanostructured titanic acid salt precursor precipitate in the solution, and separating the precipitate to obtain the titanic acid salt precursor; drying the precursor, and then heat treating it to obtain the nanostructured titanic acid salt product. The present invention provides a process for preparing a titanic acid salt with simple preparation process, easy control for process parameters and easy large-scale industrial production.

The invention provides a method for producing an aqueous dispersion of titanium oxide particles which comprises: (a) first step for subjecting an aqueous slurry of titanium oxide particles to wet dispersing treatment in the presence of 15 to 250 parts by mole of acetic acid and 15 to 90 parts by mole of nitric acid each relative to 100 parts by mole of titanium oxide with a medium agitating mill or a high pressure dispersing machine to obtaining an aqueous dispersion of titanium oxide particles before washing, and (b) a second step for washing the aqueous dispersion of titanium oxide particles before washing obtained in the first step (a) to obtain an aqueous dispersion of titanium oxide particles.

The invention further provides a method for producing an alcohol dispersion of titanium oxide particles which comprises: (c) a third step for replacing the dispersion medium of the aqueous dispersion of titanium oxide particles obtained in the second step by an alcohol solvent.

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.

Provided is a titanium oxide particle dispersion liquid with an inhibited photocatalytic activity and a low level of coloration. Titanium oxide particles in this dispersion liquid contain:

(1) a tin component; and

(2) a manganese component and/or a cobalt component,

wherein only the tin component is solid-dissolved in the titanium oxide particles, and the manganese component and/or the cobalt component are each contained by an amount of 5 to 5,000 in terms of a molar ratio to titanium (Ti/Mn and/or Ti/Co).

Provided is a titanium oxide particle dispersion liquid with an inhibited photocatalytic activity and a low level of coloration. Titanium oxide particles in this dispersion liquid contain:

(1) a tin component; and

(2) a manganese component and/or a cobalt component,

wherein only the tin component is solid-dissolved in the titanium oxide particles, and the manganese component and/or the cobalt component are each contained by an amount of 5 to 5,000 in terms of a molar ratio to titanium (Ti/Mn and/or Ti/Co).

Porous metal oxide microspheres are prepared via a process comprising forming a liquid dispersion of polymer nanoparticles and a metal oxide; forming liquid droplets of the dispersion; drying the droplets to provide polymer template microspheres comprising polymer nanospheres; and removing the polymer nanospheres from the template microspheres to provide the porous metal oxide microspheres. The porous microspheres exhibit saturated colors and are suitable as colorants for a variety of end-uses.

Porous metal oxide microspheres are prepared via a process comprising forming a liquid dispersion of polymer nanoparticles and a metal oxide; forming liquid droplets of the dispersion; drying the droplets to provide polymer template microspheres comprising polymer nanospheres; and removing the polymer nanospheres from the template microspheres to provide the porous metal oxide microspheres. The porous microspheres exhibit saturated colors and are suitable as colorants for a variety of end-uses.