Photoelectrode and Method for Preparing the Same

Abstract

The present invention relates to an photoelectrode and the preparation method thereof, wherein said photoelectrode comprises a substrate and a titania layer composed of a mesoporous titania bead having a diameter of 200-1000 nm, specific surface area of 50-100 m 2 /g, porosity of 40-60%, pore radius of 5-20 nm, pore volume of 0.20-0.30 cm 3 /g, and the titania comprised in the bead is anatase titania.

We claim: 
     
         1 . A photoelectrode, comprising:
 (1) a substrate; and   (2) a titania layer composed of a mesoporous titania bead having a diameter of 200-1000 nm, specific surface area of 50-100 m 2 /g, porosity of 40-60%, pore radius of 5-20 nm, pore volume of 0.20-0.30 cm 3 /g, and the titania comprised in the bead is anatase titania.   
     
     
         2 . The photoelectrode according to  claim 1 , wherein said substrate is a metal substrate, or a transparent non-conductive substrate covered by a transparent conductive film. 
     
     
         3 . The photoelectrode according to  claim 1 , wherein said titania layer has a thickness of 5-10 μm. 
     
     
         4 . The photoelectrode according to  claim 1 , wherein said mesoporous titania bead is prepared by the following steps:
 (1) adding a steric agent and a titanium-containing precursor into ethanol to proceed sol-gel reaction and give a sol-gel product, wherein the molar ratio of said steric agent:said titanium-containing precursor:ethanol is 0.1-1:1:200-300; and   (2) heating said sol-gel product in water at 120-200° C. for 1-24 hours to obtain the mesoporous titania bead.   
     
     
         5 . The photoelectrode according to  claim 4 , wherein said steric agent is a tertiary amine. 
     
     
         6 . The photoelectrode according to  claim 5 , wherein said tertiary amine is selected from hexamine, trimethylamine, quinoline, isoquinoline or methyldiethylamine (CH 3 N(CH 2 CH 3 )). 
     
     
         7 . The photoelectrode according to  claim 4 , wherein said titanium-containing precursor is selected from titanium tetraisopropoxide, titanium tetrachloride, titanium trichloride, ethyl orthotitanate or Ti(OC 4 H 8 ) 4 . 
     
     
         8 . The photoelectrode according to  claim 4 , further comprising adding a salt into said ethanol in step (1) to adjust ionic strength to 1×10 31 4 -32×10 −4 . 
     
     
         9 . The photoelectrode according to  claim 8 , wherein said salt is selected from KCl, LiCl, NaCl, KCl, LiF, NaF, KF, LiBr, NaBr, KBr, LiI, NaI, KI, CsCl, CsI, CsBr, KNO 3 . 
     
     
         10 . The photoelectrode according to  claim 1 , wherein said titania layer increases scattering efficiency and used as a scattering layer. 
     
     
         11 . The photoelectrode according to  claim 1 , further comprising a titania nanoparticle layer between said substrate and said titania layer. 
     
     
         12 . The photoelectrode according to  claim 11 , wherein said titania nanoparticle layer is composed of a titania nanoparticle, not composed of said mesoporous titania bead. 
     
     
         13 . The photoelectrode according to  claim 12 , wherein said titania nanoparticle of the titania nanoparticle layer is P25, ST-01, ST-21, ST-31, TTO-55S or ST-30L. 
     
     
         14 . The photoelectrode according to  claim 1 , which is used for manufacturing a cell. 
     
     
         15 . A method for preparing the photoelectrode according to  claim 1 , comprising:
 (4) providing a substrate;   (5) coating a mesoporous titania bead on said substrate to obtain a coated layer, in which said bead has a diameter of 200-1000 nm, specific surface area of 50-100 m 2 /g, porosity of 40-60%, pore radius of 5-20 nm, pore volume of 0.20-0.30 cm 3 /g, and the titania comprised in the bead is anatase titania; and   (6) pressing the coated layer from step (2) under room temperature to obtain said titania layer.   
     
     
         16 . The method according to  claim 15 , wherein said substrate is a metal substrate, or a transparent non-conductive substrate covered by a transparent conductive film. 
     
     
         17 . The method according to  claim 15 , further comprising the following step between step (1) and step (2): coating a titania nanoparticle on said substrate to obtain a titania nanoparticle layer, and said titania nanoparticle is not said mesoporous titania bead. 
     
     
         18 . The method according to  claim 15 , which is applied to cell manufacture.