Fabrication of Flower-like Rhodium-Doped fl-Ni(OH)2 as an Efficient Electrocatalyst for Methanol Oxidation Reaction in Alkaline Media

In this study, beta-Ni(OH)(2) with a unique flower-like morphology was synthesized through a hydrothermal method. The doping of Rh in beta-Ni(OH)(2) was achieved by a reduction method. The as-synthesized catalysts were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy for the crystal structure, morphology, composition, and chemical state analysis. The electrochemical tests revealed that the doping of Rh can significantly increase the electrocatalytic performance of beta-Ni(OH)(2) in 1.0 M KOH solution. The methanol oxidation peak current density of Rhdoped beta-Ni(OH)2 reached 95 mA cm(-2) with a Tafel slope of 40 mV dec(-1). The reason for these improvements is that Rh can suppress the phase transformation of NiOOH from fi to a. Meanwhile, the electronic structure change of nickel in beta-Ni(OH)(2) and the defect ratio increase caused by Rh doping are beneficial to methanol oxidation reaction (MOR) catalytic activity. Furthermore, the synergistic effect between Rh and Ni(OH)(2) improved the surface activity of beta-NiOOH. The doping of Rh in fi-Ni(OH)(2) is initiative in this work, which provides a new strategy to design highly efficient and cost-effective MOR electrocatalysts for alkaline DMFCs.