The Research On Cobalt And Nickel Sulfides Supported Carbon Nanotubes Catalysts For Oxygen Evolution Reaction Of The Waterelectrolysis

Hydrogen production by water electrolysis consumes high energy for high anodeover-potential, making the low conversion efficiency in the industry. Precious metal materialsfor oxygen evolution reaction (OER) have good activity and stability. However, they are tooexpensive and scarce to large-scale production. The transition metal cobalt, nickel compoundsas the anode catalyst of water electrolysis exhibit excellent catalytic activity and have lowprice, and thus have been extensively studied in the alkaline medium.The paper is based on the research and development of the transitional metal cobalt,nickel sulfide as anode catalysts for water electrolysis which have high catalytic activity, lowoverpotential, good stability in the alkaline medium. Two kinds of cobalt metal sulfides (suchas CoS2/CNTs and Co3S4/NCNTs) were studied, involving how to preparation, the physicaland chemical characterization and anode catalytic activity. In addition, nickel sulfide(NiS/CNTs) was prepared by reflux method and the synthetic conditions and stability ofoxygen evolution reaction were investigated. The detail content is as below.1) CoS2/CNTs catalyst was prepared by hydrothermal method, the effects of CoS2content,reaction temperature and time on oxygen evolution reaction were investigated.TheCoS2/CNTs catalyst showed good electrocatalytic activity for OER. The catalyst OERpotential valve of E=0.68V (vs SCE, the same below) was significantly lower than that ofCoS2(E=0.75V) and CNTs (E=0.73V) in the same current density (I=10mA/cm2).2) Co3S4/NCNTs catalyst was synthesized by ion exchange method, the effects of theCo3S4content and different sulfur resource onoxygen evolution reactionwere studied for OER.The Co3S4/NCNTs catalyst exhibiteda higher OER reactivity with TAA as sulfur source andthe Co3S4loading amount of20wt.%. The OER potential value of E=0.65V was significantlylower than that of Co3S4(E=0.74V) and NCNTs (E=0.68V,I=10mA/cm2).3) NiS/CNTs catalyst was prepared by low temperature reflux method. The influence ofthe cationic surfactant CTAB and calcinationonits catalytic activity for OERwas investigated.The NiS/CNTs catalyst shows better catalytic activity and higher stability.