Substrate with a photocatalytic coating

Abstract

A gas guiding device including a conduit configured to pass a gas, and a substrate on the conduit, the substrate including, a fibrous material, and a coating provided at least (i) over a portion of a surface of the fibrous material or (ii) within a volume of the fibrous material, the coating being configured to have photocatalytic properties and having at least a partially crystallized semiconducting material which has photocatalytic properties and which is of the oxide or sulphide type.

1 . A gas guiding device comprising: 
 a conduit configured to pass a gas; and    a substrate on the conduit, the substrate including, 
 a fibrous material, and  
 a coating provided at least (i) over a portion of a surface of the fibrous material or (ii) within a volume of the fibrous material, the coating being configured to have photocatalytic properties and having at least a partially crystallized semiconducting material which has photocatalytic properties and which is of the oxide or sulphide type.  
   
   
   
       2 . The gas guiding device of  claim 1 , wherein the semiconductor material is titanium oxide at least partially crystallized in anatase form.  
   
   
       3 . The gas guiding device of  claim 1 , further comprising: 
 a source of light configured to provide light to the substrate to activate the photocatalytic properties of the substrate.    
   
   
       4 . The gas guiding device of  claim 3 , wherein the source of light is one of a halogen lamp and a fluorescent tube.  
   
   
       5 . The gas guiding device of  claim 1 , wherein the substrate is provided outside the conduit.  
   
   
       6 . The gas guiding device of  claim 1 , wherein the substrate is provided inside the conduit to apply the photocatalytic properties to the passing gas.  
   
   
       7 . The gas guiding device of  claim 1 , wherein the coating is provided within a thickness of the fibrous material.  
   
   
       8 . The gas guiding device of  claim 1 , wherein the semiconducting material is introduced into the coating in the form of particles in a colloidal suspension or in the form of powder.  
   
   
       9 . The gas guiding device of  claim 1 , wherein the at least partially crystallized semiconducting material includes titanium oxide and originates from thermal decomposition of organometallic or metal halide precursor(s) within the coating.  
   
   
       10 . The gas guiding device of  claim 1 , further comprising: 
 a bonding agent that adheres the fibers of the fibrous material to each other and an adhesion promoting agent that adheres the coating to the fibers.    
   
   
       11 . The gas guiding device of  claim 10 , wherein the bonding agent includes the adhesion promoting agent.  
   
   
       12 . The gas guiding device of  claim 10 , wherein the adhesion promoting agent is an organic, mineral or organo-mineral hybrid mono- or multicomponent.  
   
   
       13 . The gas guiding device of  claim 10 , wherein the adhesion promoting agent comprises a silica-containing component of the silane, silicone, or siloxane type.  
   
   
       14 . The gas guiding device of  claim 10 , wherein the adhesion promoting agent comprises one or more organic polymers which are associated with additives which belong to the antioxidant series and/or ultraviolet absorbers and/or stabilisers of the amine type with steric hindrance.  
   
   
       15 . The gas guiding device of  claim 10 , wherein the adhesion promoting agent comprises at least one amorphous metal oxide of the TiO 2  or SiO 2  type, which originates from a thermal decomposition of silica-containing, organometallic or metal halide precursor(s) within the coating.  
   
   
       16 . The gas guiding device of  claim 10 , wherein the adhesion promoting agent comprises at least one mineral component selected from aluminium phosphates and potassium or calcium aluminosilicates.  
   
   
       17 . The gas guiding device of  claim 1 , wherein the fibrous material is arranged in the form of a web, felt, shell, paper or loose material.  
   
   
       18 . The gas guiding device of  claim 1 , wherein the coating having photocatalytic properties covers at least a portion of fibers of the fibrous material over a thickness of at least 5 nm.  
   
   
       19 . The gas guiding device of  claim 1 , wherein the coating is provided both on the portion of the surface of the fibrous material and within the volume of the fibrous material.  
   
   
       20 . An air conditioning device comprising: 
 a conduit configured to pass a gas; and    a substrate on the conduit, the substrate including, 
 a fibrous material, and  
   a coating provided at least (i) over a portion of a surface of the fibrous material or (ii) within a volume of the fibrous material, the coating being configured to have photocatalytic properties and having at least a partially crystallized semiconducting material which has photocatalytic properties of oxide or sulphide.    
   
   
       21 . A filter made of a substrate comprising a fibrous material which is provided, over at least a portion of its surface with a coating with photocatalytic properties comprising a semi-conducting material with photocatalytic properties of the oxide or sulphide type, in particular titanium oxide at least partially crystallized in anatase form, the said material being used in combination with a promoter of adhesion to the said fibrous material, wherein the adhesion promoter comprises at least one metal oxide of the SiO 2  type originating from the thermal decomposition of silicon-comprising, organometallic or metal halide precursor(s) within the coating.  
   
   
       22 . A method for purifying gaseous effluents or atmosphere comprising: 
 circulating the gaseous effluents or atmosphere through the filter of  claim 21.