▎ 摘　　要

NOVELTY - Preparing graphene-based composite visible light catalytic material comprises ultrasonic dispersing graphene oxide in deionized water to obtain graphene oxide dispersion, adding silver nitrate solution into the graphene oxide dispersion and stirring to obtain the mixed precursor solution A, stirring and dropping titanium dioxide dispersion into the mixed precursor solution A to obtain solution B, dropping phosphate solution into the mixed solution B and performing hydrothermal reaction, centrifuging, washing and vacuum drying. USE - The method is useful for preparing graphene-based composite visible light catalytic material (claimed). ADVANTAGE - The catalytic material: has good absorption in the UV-visible region of 200-800 nm and absorbance is of more than 0.4; has rhodamine B adsorption rate of 22% in 10 mg/l rhodamine B solution under dark; and ensures complete degradation of rhodamine B when irradiated with visible light at 400-800 nm for 30 minutes, after adsorption-desorption equilibrium is established (all claimed). The method is simple, and produces product with good performance and has strong degradation activity for rhodamine B under visible light. DETAILED DESCRIPTION - Preparing graphene-based composite visible light catalytic material comprises (i) dissolving graphene oxide in deionized water, and ultrasonically dispersing to obtain 0.06-0.6 wt.% graphene oxide dispersion; (ii) dissolving silver nitrate in deionized water to obtain silver nitrate solution, stirring and adding the silver nitrate solution into the graphene oxide dispersion, and stirring for 6-12 hours to obtain the mixed precursor solution A, where the concentration of silver nitrate in the mixed solution is 0.15 mol/l; (iii) dissolving titanium dioxide nanosheet in deionized water and ultrasonic dispersing to obtain titanium dioxide dispersion, stirring and dropping into the mixed precursor solution A to obtain solution B, where the titanium dioxide concentration in the mixed solution B is 0.48-1.8 wt.%; (iv) dissolving phosphate in deionized water to obtain 0.15 mol/l phosphate solution; and (v) stirring and dropping the phosphate solution into the mixed solution B until the reaction system appears green turbid, where the volume ratio of the phosphate solution and the mixed solution B is 1:4, continuously stirring for 30-60 minutes after dropping, transferring to polytetrafluoroethylene lined stainless steel sealed hydrothermal reaction kettle, reacting at 160-200 degrees C for 20-30 hours, naturally cooling the reaction kettle to room temperature, centrifuging, respectively washing with deionized water and absolute ethyl alcohol and vacuum drying.