Described herein are heterogeneous materials comprising a p-type semiconductor comprising two metal oxide compounds of the same metal in two different oxidation states and an n-type semiconductor having a deeper valence band than the p-type semiconductor valence bands, wherein the semiconductor types are in ionic communication with each other. The heterogeneous materials enhance photocatalytic activity.

A photocatalytic functional film has a structure of a substrate, a barrier layer and a photocatalytic layer stacked one on another. The barrier layer is an amorphous TiO.sub.2 film, the photocatalyst layer comprises an amorphous TiO.sub.2 film, and particles of visible light responsive photocatalytic material formed on the surface of the amorphous TiO.sub.2 film. A method for producing a photocatalytic functional film includes: adding an alcohol solvent and an acid to a titanium precursor to obtain a TiO.sub.2 amorphous sol by dehydration and de-alcoholization reaction; applying and drying the TiO.sub.2 amorphous sol on a substrate to form a barrier layer; and applying and drying a composition formed by mixing particles of visible light responsive photocatalyst material with the TiO.sub.2 amorphous sol on the barrier layer, to form a photocatalyst layer.

Visible-light response hybrid aerogel and a preparation method and application thereof in waste gas processing are disclosed. Dicyandiamide is taken as a precursor and is calcined in two times to prepare a carbon nitride nanosheet; the carbon nitride nanosheet is dispersed in water, silver metavanadate quantum dots are subjected to in-situ growth to prepare a silver metavanadate quantum dot/carbon nitride nanosheet composite material; the silver metavanadate quantum dot/carbon nitride nanosheet composite material and graphene oxide carry out hydrothermal reaction, and are then frozen and dried to prepare silver metavanadate quantum dot/carbon nitride nanosheet/graphene hybrid aerogel which is the visible-light response hybrid aerogel. The problems of large reduction dosage, serious secondary pollution, complexity in operation and the like generated when waste gas is processed by a traditional flue gas denitration technology are overcome.

A mesoporous mixed oxide catalyst that comprises silicon and at least one metal M that is selected from the group that consists of the elements of groups 4 and 5 of the periodic table and mixtures thereof, with the mass of metal M being between 0.1 and 20% of the mixed oxide mass.

A catalyst comprising a noble metal disposed on a support. The noble metal is present in an amount ranging from 0.1 wt % to 10 wt % relative to the total weight of the catalyst. The support comprises at least 50 wt % silicon carbide relative to the total weight of the support. The silicon carbide has a surface area of at least 5 m.sup.2/g. A method for preparing methyl methacrylate from methacrolein and methanol using the catalyst is also disclosed.

The present invention provides a heterojunction photocatalyst having higher photocatalytic activity than that of a conventional heterojunction photocatalyst. Further, the present invention provides a photocatalyst composite having the heterojunction photocatalyst on a substrate, a method for producing the heterojunction photocatalyst, and a method for producing hydrogen using the heterojunction photocatalyst or the photocatalyst composite The het junction photocatalyst of the present invention has a solid mediator between a hydrogen-evolution photocatalyst and an oxygen-evolution photocatalyst, and the solid mediator is selectively joined to an electrons collecting surface of the oxygen-evolution photocatalyst.

A method of treating an exhaust gas from an internal combustion engine comprising contacting the exhaust gas with a lean NO.sub.x trap catalyst is disclosed. The lean NO.sub.x trap catalyst comprises a first layer and a second layer.

The invention relates to a catalyst that comprises at least the tantalum element, at least an aldolizing element and at least a mesoporous oxide matrix, with the tantalum mass being between 0.1 and 30% of the mesoporous oxide matrix mass, the mass of the at least one aldolizing element being between 0.02 and 4% of the mesoporous oxide matrix mass, and use thereof.

Visible-light response hybrid aerogel and a preparation method and application thereof in waste gas processing are disclosed. Dicyandiamide is taken as a precursor and is calcined in two times to prepare a carbon nitride nanosheet; the carbon nitride nanosheet is dispersed in water, silver metavanadate quantum dots are subjected to in-situ growth to prepare a silver metavanadate quantum dot/carbon nitride nanosheet composite material; the silver metavanadate quantum dot/carbon nitride nanosheet composite material and graphene oxide carry out hydrothermal reaction, and are then frozen and dried to prepare silver metavanadate quantum dot/carbon nitride nanosheet/graphene hybrid aerogel which is the visible-light response hybrid aerogel. The problems of large reduction dosage, serious secondary pollution, complexity in operation and the like generated when waste gas is processed by a traditional flue gas denitration technology are overcome.

A photocatalyst, represented by the following general formula (1):
X(VO.sub.4).sub.6(OH).sub.2General Formula (1) wherein X represents Z.sub.a1Ti.sub.b1 or Z.sub.a2Ti.sub.b2Ag.sub.c2 (where Z is Ca or Sr; a1 is 7.0 to 9.5; b1 is 0.5 to 3.0; a2 is 7.0 to 9.5; b2 is 0.4 to 1.5; c2 is 0.1 to 2.0; a1+b1 is 9.0 to 10.0; and a2+b2+c2 is 9.0 to 10.0) in the general formula (1).