NOVELTY - Paste (a) is coated on one side of material (C) which is formed using steel mesh, and processed to obtain material (E). 1.2 g Substance (B) formed using activated carbon powder, deionized water and nitric acid is added into beaker, then potassium nitrate aqueous solution, nonylphenol polyoxyethylene ether aqueous solution, diethyl ether, methanol and solution (F) are added, stirred, polytetrafluoroethylene is added, stirred and heated. Resultant paste is coated on the other side of material (E), processed, calcined and cooled, to obtain three-dimensional porous electrode.    USE - Preparation of three-dimensional porous electrode used for photovoltaic system.    DETAILED DESCRIPTION - 7.5 g Activated carbon powder is added into 500 mL beaker, 100 mL deionized water is then added, boiled for 2 hours, such that impurities are removed, then vacuum-filtered and dried at 90 degrees C for 12 hours in an oven, to obtain substance (A). Substance (A) is added into 500 mL beaker, 100 mL of 0.55 mol/L nitric acid is added, stirred for 6 hours, and dried at 90 degrees C for 24 hours in oven, to obtain substance (B). 16 Cm2 steel mesh is provided into 500 mL beaker, 100 mL deionized water is then added, boiled for 1 hour, steel mesh is cleaned with 250 mL deionized water, cleaned steel mesh is added into 500 mL beaker, 100 mL of 0.1 mol/L hydrochloric acid solution is added, leached for 30 minutes, steel mesh is cleaned with 250 mL deionized water and dried, to obtain material (C). 5.5 g Substance (B) is added into 500 mL beaker, then 10 mL of 4.5 mol/L potassium nitrate aqueous solution, 9 mL of 35% nonylphenol ethoxylate aqueous solution, 45 mL ether and 35 mL methanol, stirred for 10 minutes at a rate of 100 rpm, 8.5 mL of 75 %mass polytetrafluoroethylene emulsion, stirred for 10 minutes at a rate of 100 rpm, obtained solution is heated in 90 degrees C water bath, to obtain paste (a). Paste (a) is coated on one side of the material (C) to obtain material (D). Material (D) is processed in tableting machine under reduced pressure to obtain material (E). 3 g Cetyltrimethylammonium bromide, 17 mL n-octane and 5 mL n-butanol are added into 250 mL Erlenmeyer flask, then 2 g ammonium metavanadate and 100 mL deionized water are added and heat-stirred for 15 minutes in 70 degrees C water bath at a rate of 5000 rpm, to obtain microemulsion (A1). 3 g Cetyltrimethylammonium bromide, 17 mL n-octane and 5 mL n-butanol into 250 mL conical flask, then 100 mL of 0.8 mol/L diluted sulfuric acid is added and stirred for 15 minutes at a rate of 1000 rpm, to obtain microemulsion (A2). Microemulsion (A1) and microemulsion (A2) are mixed for 10 minutes at a rate of 1000 rpm, left still for 10 hours, centrifuged for 20 minutes at a rate of 6000 rpm, supernatant is removed, and residue is washed using 15 mL of 95 %mass 5 times, to obtain solid product (m). Solid product (m) is dried at 100 degrees C for 24 hours and calcined at 500 degrees C for 2 hours in muffle furnace, to obtain product (n). 20 mg product (n) is added into 250 mL conical flask, 1.16 g polyvinylpyrrolidone and 100 mL deionized water are added, ultrasonically stirred for 10 minutes, 1 mL of 0.02 g/mL hydrogen tetrachloroaurate is added, ultrasonically stirred for 5 minutes, resultant substance is added into a conical flask, 2 mL of 1% sodium citrate solution is added, stirred at 40 degrees C for 30 minutes, centrifuged for 15 minutes at a rate of 6000 rpm, supernatant is removed, obtained residue is washed using 15 mL deionized water for 2 times and dried at 20 degrees C for 24 hours, to obtain solid product (p). Solid product (p), 2 g sodium dodecyl benzene sulfonate and 50 mL deionized water are added into 150 mL conical flask and stirred at a rate of 1000 rpm, to obtain solution (F). 1.2 g Substance (B) is added into 500 mL beaker, then 5.5 ml of 4.5 mol/L potassium nitrate aqueous solution, 4.5 ml of 35% nonylphenol polyoxyethylene ether aqueous solution, 45 mL diethyl ether, 35 mL methanol and 5 mL solution (F) are added, stirred for 10 minutes at a rate of 100 rpm, 2.5 ml of 75 %mass polytetrafluoroethylene is added, stirred at a rate of 100 rpm, and resultant solution is heated in 80 degrees C water bath, to form a paste (b). Paste (b) is coated on the other side of material (E) and processed in tableting machine under reduced pressure. Resultant material is calcined at 350 degrees C in muffle furnace and cooled, to obtain three-dimensional porous electrode.