Effect of V Doping on Electrocatalytic Performance of Ni-Co-S on Bacterial Cellulose-derived Carbon Aerogel

Abstract

Ni-Co-S/CA composite aerogels were prepared by hydrothermal method using bacterial cellulose-derived carbon aerogels (CA) as support. The microstructure and properties of the composites were adjusted via adding trace vanadium. The characterization results show that the main phase of Ni-Co-S is NiCo2S4 with the secondary phase of NiS2. With the increment of the nickel-cobalt salt concentration, the load amount increases, and the peak current density of electrocatalysis firstly upgraded and then degraded. After being doped with a small amount of vanadium at lower nickel-cobalt salt concentration, Ni-Co-S transforms from spherical particles with high crystallinity to square particles with low crystallinity, and its electrocatalytic activity and stability are improved. Under the preparative conditions of 0.01 mol/L total concentration of nickel-cobalt salt and 3mol% vanadium salt, the as-obtained electrode exhibits the optimal catalytic performance for methanol oxidation. Compared with the sample without V doping, its peak current density (78.1 mA/cm2) enhanced by 45.7% at least. The Ni-Co-S/CA composite aerogel electrodes with the advantages of light weight and high porosity, is expected to be applied in portable direct methanol fuel cell.