Deactivation resistant photocatalysts

Abstract

The present disclosure relates to a fluid purification device that has a deactivation resistant photocatalyst having nanocrystallites of less than 14 nanometers (nm) in diameter with at least 200 m2 surface area/cm3 of skeletal volume in cylindrical pores of 5 nm in diameter or larger, with the mode of the pore size distribution 10 nm or more.

1 . A fluid photocatalytic purification device comprising a deactivation resistant photocatalyst for removing contaminants from a fluid. 
     
     
         2 . The fluid photocatalytic purification device of  claim 1 , further comprising a filter. 
     
     
         3 . The fluid photocatalytic purification device of  claim 1 , further comprising an adsorbing filter. 
     
     
         4 . The fluid photocatalytic purification device of  claim 1 , wherein the fluid is air. 
     
     
         5 . The fluid photocatalytic purification device of  claim 1 , wherein the fluid is water. 
     
     
         6 . A deactivation resistant photocatalyst comprising a plurality of crystallites of less than 14 nm in diameter with at least 200 m 2  surface area/cm 3  of skeletal volume in pores of 5 nm in diameter or larger, with the mode of the pore size distribution 10 nm or more. 
     
     
         7 . The photocatalyst of  claim 6 , wherein the pores are predominately cylindrical. 
     
     
         8 . The photocatalyst of  claim 6 , wherein the plurality of crystallites are nanocrystallites of TiO 2 . 
     
     
         9 . The photocatalyst in  claim 8 , where the TiO 2  is primarily anatase. 
     
     
         10 . The photocatalyst of  claim 6 , wherein the plurality of crystallites are nanocrystallites of TiO 2  and have a plurality of pores with a diameter of at least 5 nm. 
     
     
         11 . The photocatalyst of  claim 6 , wherein the plurality of crystallites are nanocrystallites of TiO 2  that are disposed in aggregates that have at least 200 m 2  surface area per cm 3  of skeletal volume in cylindrical pores of at least 6 nm in diameter. 
     
     
         12 . The photocatalyst of  claim 6 , wherein the plurality of crystallites are nanocrystallites of TiO 2 , and wherein the nanocrystallites of TiO 2 , comprise a coating or layer of a dopant material selected from the group of metal, metal oxide, non-metal, and any combinations thereof. 
     
     
         13 . The photocatalyst of  claim 12 , wherein the dopant material is combined with the nanocrystallites of TiO 2  in the ratio of Ti (1-x) M x O 2  where Ti is titanium, x is a mole percentage and M is the doping material. 
     
     
         14 . The photocatalyst of  claim 12 , wherein the dopant material comprises a metal selected from the group consisting of tin, iron, zinc, cerium, neodymium, niobium, tungsten, and any combinations thereof. 
     
     
         15 . The photocatalyst of  claim 12 , wherein the dopant material comprises a non-metal that is nitrogen. 
     
     
         16 . The photocatalyst of  claim 12 , wherein the nanocrystallites of titanium dioxide are less than 12 nanometers in diameter. 
     
     
         17 . The photocatalyst of  claim 8 , wherein the nanocrystallites of TiO 2  form porous particles of less than 1 micron. 
     
     
         18 . A method of using a nanocrystalline TiO 2  photocatalyst to remove contaminants from fluid, water or air, comprising:
 irradiating the nanocrystalline TiO 2  photocatalyst with UV light; and   contacting contaminants with the TiO 2  photocatalyst,   wherein the nanocrystalline TiO 2  photocatalyst have nanocrystallites that are less than 14 nanometers in diameter.