TECHNOLOGY FOCUS - ELECTRONICS - Preferred Components: The conductive substrate is an electrically conductive glass plate having an electrically conductive layer on a surface of it.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The functionalized carbon nanomaterials in step (a) include acidic groups, hydroxyl groups, or amino groups as functional groups of it. The functionalized carbon nanomaterials in step (a) are acidified single-wall carbon nanotubes, acidified double-wall carbon nanotubes, acidified multi-wall carbon nanotubes, acidified carbon nanohorns, or acidified carbon nanocapsules. The functionalized carbon nanomaterials are acidified single-wall, double-wall, or multi-wall carbon nanotubes. The carbon nanotubes are multi-wall carbon nanotubes having a length of 1 -25 mu m, a diameter of 1-50 nm, a specific surface area of 150-250 m2/g, and an aspect ratio of 20-2500. The TiO2 precursor is titanium alkoxide (preferred), titanium chloride, titanium oxysulfate, or titanium sulfate. The titanium alkoxide is titanium tetra-isopropoxide. Preferred Process: The precursor is reacted under sol-gel conditions in step (c). In step (b) the dissolving or dispersing of a TiO2 precursor in a dispersion obtained from step (a) is carried out using supersonic treatment. The step of reacting the precursor under sol-gel conditions comprises adding water into the mixture obtained in step (b), and allowing the titanium alkoxide to undergo hydrolytic and condensation reactions. The step of reacting the precursor under sol-gel conditions further comprises adding an acid into the mixture undergoing the hydrolytic and condensation reactions. In the process, the water added has a weight that is 100-1000% the weight of carbon nanomaterials, and the acid added is of a volume that adjusts pH value of the mixture undergoing the hydrolytic and condensation reactions to 1-5. The autoclave in step (d) is set at 150-300 degrees C, and the heating time is 10-30 hours. In step (f), the mixture is concentrated into a paste comprising 100-250 g of a solid content per liter. The coating in step (g) is carried out by using the doctor-blade method.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The liquid medium in step (a) is an alcohol (preferably isopropyl alcohol having a weight that is 200-1200% the weight of carbon nanomaterials), while the dispersing is carried out using supersonic treatment.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The polymer solution in step (e) is an aqueous solution of a polymer having a weight average molecular weight of 200-30000 g/mol. Preferred Components: The polymer is polyol, cyclodextrin, or cellulose (preferably polyethylene glycol (preferred), polypropylene glycol, or polybutylene glycol). EXAMPLE - Acidified multi-wall carbon nanotubes (MWCNTs) (0.0064 g) were added into anhydrous isopropyl alcohol (60 ml). The acidified MWCNTs were evenly dispersed in anhydrous isopropyl alcohol under supersonic vibration, which was followed by the addition of tetra-isopropoxide (TTIP) (23.5 g) in it, and the mixture was subjected to supersonic vibration for 30 minutes continuously. The evenly dispersed solution of acidified MWCNTs/TTIP/isopropyl alcohol was then slowly poured into a beaker that contained deionized water (150 ml), and the pH value of the solution was adjusted to 1.8 by using 69% nitric acid, then the solution was heated at 80 degrees C. The isopropyl alcohol was allowed to evaporate completely during heating, which resulted in acidified MWCNTs/titanium dioxide (TiO2) colloidal solution (130 ml). The MWCNTs/TiO2 colloidal solution was put into an autoclave and heated at 200 degrees C for 12 hours. After allowing the solution to cool down, a MWCNTs/anatase TiO2 colloidal solution was obtained. Subsequently, 40 wt.% polyethylene glycol 20000 aqueous solution (2.644 g) was added into the MWCNTs/anatase TiO2 colloidal solution, and the resulted mixture was vigorously stirred for 1 hour to give a mixture, which was concentrated into a highly viscous paste comprising nanocomposites (170 g in every liter of mixture under reduced pressure). The paste was then coated on an insulating surface of a fluorine doped tin oxide (FTO) conductive glass plate by using the doctor-blade method. The conductive glass plate was left to dry for 1 hour under room temperature, and then subjected to calcination in air at 45 degrees C for 30 minutes, so as to obtain a photoanode substrate of nano semiconductor composites. The fabricated photoanode substrate of nano semiconductor composite materials was immersed in a dye solution (cis-dithiocyanato-N,N'-bis(2,2'-bipyridyl-4-carboxylicacid-4'-tetrabutyl ammonium carboxylate)ruthenium (II) dissolved in a mixed solvent of acetonitrile and tert-butyl alcohol at a ratio of 1:1 (V:V)) having N719 dye at room temperature for 10-24 hours. The photoanode substrate with dyes adsorbed was kept in ethanol for 6-15 hours in order to desorb excessive dyes.