▎ 摘　　要

NOVELTY - High-efficiency cobalt tungstate/nitrogen-doped graphene electrocatalyst comprises cobalt tungstate, nitrogen-doped graphene sheet cobalt tungstate is supported on nitrogen-doped graphene sheet, is prepared by adding natural graphite powder. USE - High-efficiency cobalt tungstate/nitrogen-doped graphene electrocatalyst. ADVANTAGE - The high-efficiency cobalt tungstate/nitrogen-doped graphene electrocatalyst is simple to prepare in cost effective manner, contains green raw material, and has good repeatability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing high-efficiency cobalt tungstate/nitrogen-doped graphene electrocatalyst, which involves: (A) adding natural graphite powder and sodium nitrate to cold concentrated sulfuric acid, and then stirring the ice water bath continuously; Slowly adding potassium permanganate at 20 degrees C; (B) stirring the mixture at 35 degrees C for 30 minutes, slowly adding deionized water at 95 degrees C, and maintaining this temperature for 1 hours; (C) adding deionized water while adding hydrogen peroxide to the mixed solution; (D) filtering the solid product after hot filtration, and repeatedly washing with hydrochloric acid solution until the filtrate no longer has sulfate; (E) ultrasonically washing mixed solution for 3-4 times with deionized water, and then centrifuging for 10 minutes by a 6000 revolutions per minute high-speed centrifuge to remove the residue; (F) collecting retained graphene oxide solution, and finally dispersing in an aqueous solution to form 5 mg/mL graphene oxide solution; (G) Dissolving cobalt chloride hexahydrate and sodium tungstate dihydrate in water under stirring, then adding ammonia water, stirring and adding a certain amount of oxidation obtained Graphene solution; (H) tranferring mixed solution to a Teflon-lined reaction vessel, sealed and reacted in a blast oven at 180 degrees C for 12 hours, cooling to room temperature; (I) centrifuging obtained powder by using deionized water and washing with aqueous ethanol for three times alternately and drying in a vacuum oven at 60 degrees C for 4 hours; (J) dissolving 5 mg solid product obtained in 1 mL (V isopropanol and V water in mass ratio of 2:1) in the solution and treating ultrasonically for 30 minutes; and (K) adding 40 mu L naphthol to sonicate for 30 minutes to use a pipette to remove 5 mu L amount on the prepared glassy carbon electrode.