▎ 摘　　要

NOVELTY - Preparing graphene/cobalt sulfide composite electrode material involves mixing cobalt salts and sulfur-containing ligands to form deep eutectic solvents (DESs). The DESs are coated on electrode substrate and fired to obtain graphene/cobalt sulfide composite electrode material. The DESs represents eutectic solvents. USE - Method for preparing graphene/cobalt sulfide composite electrode material used as catalyst in electrocatalysis, hydrogen evolution or total decomposition of seawater (claimed). ADVANTAGE - The method enables to prepare graphene/cobalt sulfide composite electrode material that has mild reaction conditions, low energy consumption, industrial production and high electrocatalytic seawater decomposition performance, and in simple, cost-effective and eco-friendly manner.