▎ 摘　　要

NOVELTY - A graphene/silver vanadate nanocomposite visible-light catalyst is formed by combining silver vanadate with graphene, where nano-silver vanadate is deposited on graphene sheet. The silver vanadate is nanotubular structure, has diameter (30-60 nm), and has length (0.4-2 microns). The catalyst has strong absorbance in visible light regions having wavelength of 400-800 nm; has absorbance (0.98-1.15); has excellent photocatalytic degradation effect to rhodamine B under irradiation of visible light; and has degradation rate of greater than or equal to 70% in 20 minutes. USE - As graphene/silver vanadate nanocomposite visible-light catalyst (claimed). ADVANTAGE - The nanocomposite visible-light catalyst has strong absorbance in the visible light regions having wavelength of 400-800 nm; has an absorbance of 0.98-1.15; has excellent photocatalytic degradation effect to rhodamine B under irradiation of visible light; has degradation rate of greater than or equal to 70% in 20 minutes; has mild degradation effect; and has total degradation rate of rhodamine B in 3 hours is 76%. DETAILED DESCRIPTION - A graphene/silver vanadate nanocomposite visible-light catalyst is formed by combining silver vanadate with graphene, where nano-silver vanadate is deposited on graphene sheet. The silver vanadate is nanotubular structure, has diameter (30-60 nm), and has length (0.4-2 microns). The catalyst has strong absorbance in the visible light regions having wavelength of 400-800 nm; has an absorbance of 0.98-1.15; has excellent photocatalytic degradation effect to rhodamine B under irradiation of visible light; has degradation rate of greater than or equal to 70% in 20 minutes; has mild degradation effect; and has total degradation rate of rhodamine B in 3 hours is 76%. An INDEPENDENT CLAIM is included for preparing the graphene/silver vanadate nano-composite visible-light catalyst involving dissolving ammonium metavanadate and surfactant P123 in deionized water, adding 1 mol/l of nitric acid, stirring to obtain a mixed solution A, where the concentration of ammonium metavanadate in the mixed solution A is 1.25-5 wt.%, the concentration of P123 is 0.8-41.7 wt.%, and the concentration of nitric acid is 0.08-1.82 mol/l; dispersing graphene oxide in water, performing ultrasonic treatment for 3-5 hours to obtain a graphene oxide solution having a concentration of 0.02-1 wt.%; adding silver nitrate to the graphene oxide solution to obtain a mixed solution B, then transferring the mixed solution B into an inner container of a polytetrafluoroethylene reactor liner of 100 ml; then dripping the mixed solution A to the polytetrafluoroethylene reactor liner filled with the mixed solution B of graphene oxide and silver nitrate, continuously stirring the solution, where the concentration of silver nitrate in the finally mixed solution of the total reactant system; and placing the reactor liner filled with the reactant in the third step into a stainless steel sleeve, sealing the reactor, keeping the temperature at 150-200 degrees C at 12-24 hours for performing hydrothermal treatment, then naturally cooling the reactor to room temperature, detaching the reactor, cleaning and centrifuging the obtained samples with deionized water and acetone, and drying the samples in vacuum.