▎ 摘　　要

NOVELTY - A graphene material is prepared by adding 50 ml sulfuric acid in 200 ml beaker, heating to 90 degrees C, stirring 10 g potassium persulfate and 10 g phosphorus pentoxide, completely dissolving solid, controlling temperature to 80 degrees C, slowly adding 12 g graphite powder, allowing bubbles to occur, maintaining temperature at 80 degrees C, reacting for 4.5 hours, naturally cooling to room temperature, transferring into 2 L beaker, diluting with water to 2 L, vacuum filtering, washing until neutral, obtaining graphene suspension, centrifugally separating suspension, repeatedly washing, and vacuum drying. USE - Preparation of graphene material for electrochemical sensor used for detecting bishphenol A (claimed). ADVANTAGE - Electrochemical sensor has high selectivity and sensitivity, good reproducibility, stability, and interference performance, and long storage life, and preparation process is low-cost and simple. DETAILED DESCRIPTION - A graphene material is prepared by adding 50 ml sulfuric acid (H2SO4) in 200 ml beaker, heating to 90 degrees C, stirring 10 g potassium persulfate (K2S2O8) and 10 g phosphorus pentoxide (P2O5), completely dissolving solid, controlling temperature to 80 degrees C, slowly adding 12 g graphite powder, allowing bubbles to occur, maintaining temperature at 80 degrees C, reacting for 4.5 hours, naturally cooling to room temperature, transferring into 2 L beaker, diluting with water to 2 L, vacuum filtering and washing until neutral, drying at 60 degrees C, obtaining 1st material, subjecting 1st material to Hummers method and oxidizing, adding 10 ml of 98% H2SO4 into 3-mouth bottle, cooling in ice bath to 0 degrees C, stirring 0.2 g preoxidation product and 1 g potassium permanganate (KMnO4), controlling temperature to less than or equal to 10 degrees C, stirring reaction for 1 hours, allowing color of solution to turn into purple, placing 3-mouth bottle in water bath at 35 degrees C with stirring, reacting for 2 hours, allowing solution to turn into green color, dropping 18 ml distilled water, controlling temperature to 50 degrees C, reacting for 2 hours, adding 48 ml distilled water, adding 1 ml of 30 mass% hydrogen peroxide, centrifuging and washing until neutral, drying at 60 degrees C, ultrasonically dispersing graphene oxide in distilled water, adding 200-800 mg polyvinylpyrrolidone, magnetically stirring at 40-60 degrees C for 8-16 hours, obtaining solution A, controlling temperature of solution A to 80-10 degrees C, adding 15-35 mu l hydrazine hydrate and 300-700 L aqueous ammonia, obtaining solution B, reacting solution B at 80-100 degrees C for 0.5-3 hours, obtaining graphene suspension, performing centrifugal separation of graphene suspension liquid, repeatedly washing, and vacuum drying at 30-60 degrees C until weight is constant in which mass ratio of graphene oxide and polyvinylpyrrolidone is 1:10-1:25, volume ratio of hydrazine hydrate and aqueous ammonia is 1:30-1:60, and mass ratio of graphene oxide and hydrazine hydrate is 4:1-1:1. An INDEPENDENT CLAIM is included for preparation of electrochemical sensor which involves adding graphene material to distilled water, ultrasonically dispersing obtain stable graphene water dispersing liquid, aqueous graphene water dispersing liquid, adding aqueous graphene water dispersing liquid to glassy carbon electrode, and evaporating volatile solvent in which concentration of aqueous graphene dispersing liquid is 0.0005-0.002 mg/L and single sequence modified electrode of dispersion liquid is 2-10 mu l.