▎ 摘　　要

NOVELTY - Preparing three-dimensional porous graphene-ceria composite photocatalyst involves preparing graphene oxide mixture by adding 300-500mg graphite powder and 1.8-2.0g sodium nitrate to 18-20ml of 98% concentrated sulfuric acid and stirring mixture at less than or equal to 5 degrees C. The 2.0-3.0g potassium permanganate powder is added and mixture is stirred at 5 degrees C for 1.5-2.0 hours. The reaction mixture is heated to 35-40 degrees C for 1-1.5 hours. The 40-50ml deionized water is added and mixture is heated to 90-100 degrees C for 10-15 minutes. The reaction product is then cooled to room temperature. USE - Method for preparing three-dimensional porous graphene-ceria composite photocatalyst used as super capacitor, and material of lithium ion battery and fuel battery (claimed). ADVANTAGE - The method enables to prepare three-dimensional porous graphene-ceria composite photocatalyst that is durable, and has excellent light catalyzing performance, good organic pollutant degradation performance and wide range of applications. DETAILED DESCRIPTION - Preparing three-dimensional porous graphene-ceria composite photocatalyst involves preparing graphene oxide mixture by adding 300-500mg graphite powder and 1.8-2.0g sodium nitrate to 18-20ml of 98% concentrated sulfuric acid and stirring mixture at less than or equal to 5 degrees C. The 2.0-3.0g potassium permanganate powder is added and mixture is stirred at 5 degrees C for 1.5-2.0 hours. The reaction mixture is heated to 35-40 degrees C for 1-1.5 hours. The 40-50ml deionized water is added and mixture is heated to 90-100 degrees C for 10-15 minutes. The reaction product is then cooled to room temperature and diluted with 70-100ml deionized water. The 10-15ml of 35 wt.% hydrogen peroxide solution is added and mixture is filtered. The filtered cake is washed three times with 300-400ml of 5% hydrochloric acid and then three times with deionized water. The filtrate is dispersed in 20-40ml deionized water and sonicated for 1.5-2 hours to obtain graphene oxide dispersion. The 40-80mg of cerium trichloride is dissolved in 10-20ml deionized water and then added to graphene oxide dispersion. The hydrothermal reaction of graphene oxide and cerium trichloride is carried out. The 100-800 microliters of 28 wt.% ammonia is added and reaction mixture is ultrasonically treated in polytetrafluoroethylene lined autoclave at 180 degrees C for 12 hours. The obtained hydrogel product is subjected to freeze-drying to obtain three-dimensional porous graphene-ceria composite catalyst.