▎ 摘　　要

NOVELTY - Preparing composite photocatalyst involves: (1) dissolving indium chloride powder in a mixed solvent of deionized water/absolute ethanol, stirring, mixing ammonium hydroxide aqueous solution and anhydrous ethanol to form an ammonium hydroxide solution, quickly adding ammonium hydroxide solution to the indium chloride solution, immediately stirring and mixing to form a white precipitate, placing in an oil bath, stirring, naturally cooling to room temperature, centrifuging the suspension to collect precipitate, washing, drying to obtain white indium hydroxide powder, calcining, and cooling to prepare light yellow indium oxide powder; (2) preparing hydrogenated indium oxide powder; and (3) dispersing graphene two-dimensional nanosheets in deionized water to form a graphene aqueous solution, adding the hydrogenated indium oxide powder to the graphene aqueous solution, ultrasonically processing to obtain a graphene/hydrogenated indium oxide suspension, and freeze-drying. USE - The method is useful for preparing composite photocatalyst (claimed) for hydrogen production. ADVANTAGE - The method realizes modification of photocatalyst, solves the problems of poor redox ability of photocatalyst, easy recombination of photogenerated carriers, and insufficient visible light response to large extent, and provides photocatalyst, which has high efficiency, photocatalytic hydrogen production activity, and photocatalytic stability of indium oxide. DETAILED DESCRIPTION - Preparing composite photocatalyst involves: (1) dissolving indium chloride powder in a mixed solvent of deionized water/absolute ethanol in a volume ratio of 3:1, stirring to form an indium chloride solution, uniformly mixing 28-30 %mass ammonium hydroxide aqueous solution and anhydrous ethanol in a volume ratio of 1:3 to form an ammonium hydroxide solution, quickly adding an equal volume of ammonium hydroxide solution to the indium chloride solution, immediately stirring and mixing to form a white precipitate, placing in an oil bath at 80 degrees C, stirring for 30 minutes, then removing suspension from the oil bath, naturally cooling to room temperature, centrifuging the suspension at high speed to collect precipitate, washing with deionized water and absolute ethanol, drying in a vacuum oven at 60 degrees C for 12 hours to obtain white indium hydroxide powder, calcining in air at 700 degrees C for 5 hours, and naturally cooling to prepare light yellow indium oxide powder; (2) adding 0.5-2 g indium oxide powder to a hydrogenation reactor, sealing the reactor, vacuumizing to less than 10 Pa, then heating the reactor to set hydrogenation temperature at a preset heating rate, filling the reactor with high-purity hydrogen with a purity of greater than 99.999% until it reaches the set hydrogen pressure, carrying out hydrogenation reaction, naturally cooling the reactor to room temperature, releasing the internal hydrogen pressure, and taking out the sample to prepare hydrogenated indium oxide powder; and (3) dispersing graphene two-dimensional nanosheets in deionized water to form a uniformly dispersed graphene aqueous solution, adding the hydrogenated indium oxide powder to the graphene aqueous solution, ultrasonically processing to obtain a uniformly dispersed graphene/hydrogenated indium oxide suspension, and subjecting to vacuum freeze-drying treatment. An INDEPENDENT CLAIM is included for the composite photocatalyst, which comprises hydrogenated indium oxide nanoparticles uniformly distributed on graphene two-dimensional nanosheets. The particle size of the hydrogenated indium oxide nanoparticles is 20-80 nm.