Porous Ni2P nanoflower supported on nickel foam as an efficient three-dimensional electrode for urea electro-oxidation in alkaline medium. (10th May 2018)

• Record Type: Journal Article
• Authors: Wang, Gang; Ye, Ke; Shao, Jiaqi; Zhang, Yingying; Zhu, Kai; Cheng, Kui; Yan, Jun; Wang, Guiling; Cao, Dianxue
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 19(2018)
• Page Start: 9316
• Page End: 9325
• Publication Date: 2018-05-10
• Subjects: Ni2P -- Porous nanosheet -- Electrocatalyst -- Anode -- Urea electro-oxidation; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.03.221
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Porous Ni2 P nanoflower supported on nickel foam (Ni2 P@Ni foam) electrodes are synthesized via a simple hydrothermal growth strategy accompanied with further phosphating treatment. The prepared electrodes are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Electro-catalytic performances towards urea electro-oxidation are tested by cyclic voltammetry (CV), chronoamperometry (CA) coupled with electrochemical impedance spectroscopy (EIS). By phosphating Ni(OH)2 precursor, the final obtained Ni2 P@Ni foam electrode presents a porous Ni2 P nanoflower structure within abundant porosity, and so exposes a large amount of electro-catalytic active sites and electronic transmission channels to accelerate the interfacial reaction. Compared with Ni(OH)2 @Ni foam precursor, the Ni2 P@Ni foam catalyst exhibits more excellent electro-catalytic activity as well as lower onset oxidation potential. Remarkably, the Ni2 P@Ni foam catalyst reaches a peak current density of 750 mA cm −2 with an onset oxidation potential of 0.24 V (vs. Ag/AgCl) accompanied by an excellent stability in 0.60 M urea with 5.00 M KOH solutions. Benefiting from the unique porous nanosheet structure, the as-synthesized Ni2 P@Ni foam catalyst performs a highly enhanced catalytic behavior for alkaline urea electro-oxidation, indicating that the material can be hopefully applied in direct urea fuel cells. Graphical abstract: Highlights: The Ni2 P@Ni foam electrode presents a porous Ni2 P nanoflower structure within abundant porosity. It exhibits a lower onset oxidation potential and much higher electro-catalytic activity towards urea electro-oxidation. It achieves the onset oxidation potential of 0.24 V vs. Ag/AgCl and peak current density of 750 mA cm −2 for urea oxidation.