▎ 摘　　要

NOVELTY - Preparing reduced graphene oxide (RGO)/ bismuth vanadate (BiVO4) crystal with adsorption property comprises e.g. (i) dissolving bismuth(iii) nitrate pentahydrate in dilute nitric acid and stirring uniformly, then adding oleic acid, n-heptane and acetone, stirring uniformly, adding sodium hydroxide solution to form precursor solution, stirring the precursor liquid to obtain bismuth(iii) oxide, washing and drying, and (ii) pouring concentrated sulfuric acid into Erlenmeyer flask, cooling, adding graphite, sodium nitrate and potassium permanganate, stirring, heating the mixture and cooling. USE - The reduced graphene oxide-bismuth vanadate crystal is used in the photocatalytic reaction or other practical uses. ADVANTAGE - The method is suitable for the stable formation of bismuth vanadate/reduced graphene oxide crystal in different extreme environments. The bismuth vanadate/reduced graphene oxide crystal has good adsorption properties. DETAILED DESCRIPTION - Preparing reduced graphene oxide (RGO)/ bismuth vanadate (BiVO4) crystal with adsorption property comprises (i) dissolving A mmol of bismuth(iii) nitrate pentahydrate in B ml of dilute nitric acid and stirring uniformly, then adding C ml of oleic acid, D mL of n-heptane and E ml of acetone, stirring uniformly, adding F ml of sodium hydroxide solution to form precursor solution, stirring the precursor liquid at room temperature for 6-8 hours to obtain bismuth(iii) oxide, washing bismuth(iii) oxide and drying; where the ratio of A, B, C, D, E and F is 1:(8-10):(2.5-3.5):(2.5-3.5):(9-11):(4-6), the concentration of dilute nitric acid is 0.95-1.05 mol/l, and the concentration of sodium hydroxide solution is 9-11 mol/l, (ii) using M ml of concentrated sulfuric acid is pouring into an Erlenmeyer flask, cooling to 0 degrees C and maintaining constant temperature under continuous stirring conditions, taking X g graphite, Y g sodium nitrate and Z g potassium permanganate adding sequentially, where ratio of M, X, Y and Z is (100-130):5:(4-6):(12-18), stirring uniformly, then heating the mixture to 25 degrees C, stirring and keeping at 2.5-3.5 degrees C, and raising the temperature of the mixed solution to 25 degrees C, heating the mixed solution to 35 degrees C, stirring and keeping for 0.5-4 hours; then cooling the mixed solution to 0 degrees C and keeping at a constant temperature for 1.5-2.5 hours, then sequentially adding deionized water and hydrogen peroxide solution to obtain dark brown graphene oxide (GO) products, where the volume ratio of the mixed solution to the deionized water and the hydrogen peroxide solution is (100-130):(300-500):(50-100), washing the dark brown graphene oxide products, centrifuging and drying to obtain graphene oxide flakes, (iii) dissolving the graphene in the aqueous ethanol solution, and obtaining the graphene oxide suspension with a concentration of 1.8-2.2 g/l by ultrasonic dispersion, dissolving bismuth(iii) oxide in absolute ethanol, and adding acetic acid in dropwise manner until the solution became white to obtain a bismuth(iii) oxide suspension having a concentration of 0.015-0.025 mol/l, dissolving ammonium metavanadate in hot deionized water, heating and stirring until ammonium metavanadate is completely dissolving to obtain a transparent yellow-brown ammonium metavanadate solution having a concentration of 0.035-0.045 mol/l, (iv) mixing the ammonium metavanadate solution is mixed into bismuth(iii) oxide suspension according to the mol ratio of Bi and V is 1:1, stirring uniformly, then adding with graphene oxide suspension, appearing bright yellow precipitate, and continuously stirring to obtain golden yellow mixture, where the mass fraction of the graphene oxide suspension in the golden yellow mixture is 15-40 wt.%; (v) adding a 5-17 mol/l sodium hydroxide solution into the golden yellow mixture and stirring for 30-60 minutes to obtain a precursor solution, where the volume ratio of the golden yellow mixture solution and the sodium hydroxide solution is (34-46):(4-6), and (vi) pouring the precursor solution into a hydrothermal kettle and is subjecting to a hydrothermal reaction at 180 degrees C for 6-10 hours, after the completion of the reaction, cooling the precursor solution to room temperature and washing and drying the product to obtain reduced graphene oxide (RGO)/bismuth vanadate (BiVO4) crystal with adsorption property. An INDEPENDENT CLAIM is also included for reduced graphene oxide-bismuth vanadate crystal with adsorption property is prepared by the above mentioned method, where the crystal is a mixed crystal of bismuth vanadate and reduced graphene oxide, where bismuth vanadate is monoclinic phase structure, and the spatial structure group is I2/b (15), the flaky graphene oxide is deoxidized to reduced graphene oxide during the hydrothermal reaction, the bismuth vanadate/reduced graphene oxide crystal was darkly adsorbing in rhodamine B solution for 30 minutes, and the dark adsorption rate of rhodamine B solution is 25.65-38.81%.