▎ 摘　　要

NOVELTY - The preparation of electrocatalyst involves adding foam nickel to concentrated hydrochloric acid, cleaning to obtain surface nickel oxide layer of foam nickel, removing oxide layer, cleaning, washing to obtain foamed nickel substrate, adding cobalt nitrate hexahydrate, ammonium fluoride and urea to deionized water to obtain dark red clear solution, placing foamed nickel substrate in PTFE reactor, adding deep red clear solution so that substrate is immersed in solution, placing in heating furnace, heating, heat preserving, reacting, cooling to room temperature, cleaning, and drying. USE - Preparation method of nano cobalt/graphene core-shell structure electrocatalyst (claimed). ADVANTAGE - The method enables preparation of nano cobalt/graphene core-shell structure electrocatalyst at reduced cost, with high stability and long shelf life. DETAILED DESCRIPTION - The preparation of electrocatalyst involves adding foam nickel to 36-38% concentrated hydrochloric acid, ultrasonically cleaning for 1-5 minutes to obtain surface nickel oxide layer of foam nickel, removing surface nickel oxide layer, ultrasonically cleaning with ethanol for 1-5 minutes, washing with deionized water to obtain foamed nickel substrate, adding cobalt nitrate hexahydrate, ammonium fluoride and urea to deionized water to obtain dark red clear solution, where mass ratio of cobalt nitrate to ammonium fluoride is 1:(0.2-5), mass ratio of cobalt nitrate to hexahydrate is 1:(0.2-5), mass ratio of cobalt nitrate hexahydrate to deionized water is 1 g: (20-100) ml, placing foamed nickel substrate in PTFE reactor, adding deep red clear solution so that substrate is immersed in solution, tightening the lid, placing in heating furnace, heating at 80-200 degrees C, heat preserving for 6-12 hours, reacting, naturally cooling to room temperature, alternately cleaning substrate with distilled water and anhydrous ethanol, placing in vacuum oven, drying at 80-100 degrees C for 8-12 hours to obtain flaky cobalt oxide precursor, placing precursor in plasma chemical vapor deposition vacuum apparatus, evacuating, passing hydrogen and argon, adjusting hydrogen and argon gas flow rate at 10-100 sccm, adjusting the pressure in vacuum apparatus at 100-300 Pa, raising the temperature to 200-800 degrees C, passing carbon source gas, adjusting carbon source gas flow rate at 10-100 sccm, adjusting argon gas flow rate at 10-100 sccm and hydrogen gas flow rate at 10-200 sccm, adjusting vacuum pressure at 200-500 Pa, radio frequency (RF) power at 50-200 W, pressure at 200-500 Pa, carbon gas flow rate at 10-100 sccm, argon gas flow rate at 10-100 sccm, hydrogen gas flow rate at 10-200 sccm, temperature at 200-800 degrees C, deposition time 10-900 seconds, turning off the power, stopping the introduction of carbon source gas and hydrogen, and cooling to room temperature under argon atmosphere.