Development of efficient and earth abundant electro-catalysts for oxygen evolution reaction (OER) greatly hampered the realistic large scale production of hydrogen by electrolysers. Bimetal iron/nickel (oxo)hydroxide represents a promising OER catalyst for its high intrinsic activity and stability. To enhance its conductivity and density of active sits, we rationally immobilized amorphous FexNi(1-x)OOH nano-particles on SnO2 nanotube arrays by a mild all solution process. The SnO2 layer does not only function as a conductive matrix, but also guarantee the successful in-situ decoration of FexNi(1-x)OOH species instead of oxidative corrosion of the Nickel foam substrate by FeCl3 in the solution. Multiple physical characterizations confirmed the successful construction of the tubular architecture of SnO2 and the even dispersing of FexNi(1-x)OOH particles (SEM, TEM, XPS and Raman etc.). Its outstanding catalytic activity in basic solution in terms of a quite low overpotential of 250 mV at 50 mA cm-2 was demonstrated by electrochemical measurements (fig.1-h), and was ensured benefiting from the amorphous nature of FexNi(1-x)OOH nano-particles and the elegant tubular array micromorphology feature.
Fig. 1. SEM image (a, b) and element mapping (c, d, e, f and g) of NixFe(1-x)OOH/SnO2 nanotube arrays; (h) Linear Sweep Voltammetry (LSV) curves of NixFe(1-x)OOH@SnO2 NTA/Ni foam (purple), NiOOH@SnO2 NTA/Ni foam (blue), FeOOH@SnO2 NP/Ni foam (green), SnO2 NTA/Ni foam (red line) and bare Ni foam (black line) in alkaline solution. Dash line shows the LSV curve of NixFe(1-x)OOH@SnO2 NTA/Ni foam in the same solution with 70% iR compensation,. Condition: 1.0 M KOH. Scan rate 5 mV s-1.
. Nian-Tzu Suen, Sung-Fu Hung, Quan Quan, Nan Zhang, Yi-Jun Xu, Hao Ming Chen, Chem. Soc. Rev., 2017, 46, 337—365.