Porous Nickel Fibers with Enhanced Electrocatalytic Activities on Electro-oxidation of Ethanol in Alkaline Media

Well-dispersed mesoporous nickel fibers with large specific surface areas were first reported as anode catalysts for the electro-oxidation of ethanol. The porous nickel fibers could be obtained by an easily controlled and template-free coordination precipitation-thermal deposition method using NiCl 2 6H 2 O and oxalic acid as the raw materials and ammonia as the complexing and morphology-controlling agent. The method was low cost and suitable for mass production. The resulting nickel material showed a significant advantage of the hierarchical porous structure with fibrous morphology and a large specific surface area of 7.9 m 2  g −1 . The nickel fibers/GCE exhibited significantly higher electrocatalytic peak current density of 63 mA cm −2 with a lower Tafel slope of 58.7 mv dec −1 . It also showed lower charge transfer resistance in the presence of ethanol ( c  = 0.2 mol L −1 ) compared with those of the purchased spherical nickel powders. The superior electrocatalytic performance makes the as-prepared mesoporous fibers promising candidates for electrochemical catalyst materials in direct alkaline ethanol fuel cells (DAEFCs).