▎ 摘　　要

NOVELTY - Preparing high-purity graphene oxide comprises e.g. (i) inserting fixed shape of graphite as positive and cathode electrode in parallel into deionized water, maintaining the distance of the graphite electrode, (ii) placing magnetic stirrer at the bottom of the deionized water container, placing the entire electrochemical reaction system vertically above the magnetic stirrer, rotating the magnetic stirrer, (iii) using conventional DC power supply and applying, setting the voltage and magnetic stirring speed unchanged, carrying out the electrochemical reaction, stopping the reaction after the deionized water turns into brown-black suspension, (iv) filtering the brown-black suspension with filter paper, drying under freezing or supercritical conditions to obtain high-purity graphene oxide having diameter of 0.001-10 mu m, forming the graphite material into rod shape, rectangular parallelepiped shape or round cake shape. USE - The graphene oxide is useful for bioimaging, probe/sensing, and medical therapy as electrode material or conductive additive for energy storage devices and catalyst carriers. ADVANTAGE - The method: is simple process, easy to large scale preparation; the obtained product has high purity, high oxidation degree, excellent water solubility and easy dispersion. DETAILED DESCRIPTION - Preparing high-purity graphene oxide comprises (i) inserting fixed shape of graphite as positive and cathode electrode in parallel into deionized water having conductivity of 1-30 Omega gamma m1, maintaining the distance of the graphite electrode at 0.5-100 cm, (ii) placing magnetic stirrer at the bottom of the deionized water container, placing the entire electrochemical reaction system vertically above the magnetic stirrer, rotating the magnetic stirrer at speed of 10-3000 rotations/minute (rpm) to promote the uniform rotation of the deionized water, (iii) using conventional DC power supply and applying DC voltage of 1-100 V between the two graphite electrodes through the wire, setting the voltage and magnetic stirring speed unchanged, carrying out the electrochemical reaction for 1-200 hours, stopping the reaction after the deionized water turns into brown-black suspension, (iv) filtering the brown-black suspension with filter paper for 1-10 times to obtain brownish yellow aqueous solution, drying under freezing or supercritical conditions to obtain high-purity graphene oxide having diameter of 0.001-10 mu m, forming the graphite material into rod shape, rectangular parallelepiped shape or round cake shape, where the graphite material is analytically pure or spectrally pure, the magnetic stirrer has length of 1-10 cm and diameter of 0.1-1 cm, equipped the bottom of the container with deionized water has magnetic stirrer rotating at constant speed, maintaining distance 1-5 cm between the magnetic stirrer and graphite electrode, cannot be in contact with the graphite electrode, the filter paper for brown-black suspension filtration is qualitative or quantitative filter paper, and the graphene has purity greater than 99.99%.