Anodization of NiFe Foam for Water-Oxidation Reaction under Neutral Conditions
Negah Hashemi, Robabeh Bagheri, Subhajit Nandy, Keun Hwa Chae, Mohammad Mahdi Najafpour
Abstract
Large-scale solar-driven water splitting requires developing practical and durable oxygen-evolution reaction (OER) catalysts. Herein, a NiFe (hydr)oxide-based electrode that undergoes operation at 50 V is introduced as an effective and durable electrocatalyst under neutral conditions. The electrocatalyst produced on the surface of the foam is examined through several methods. All of the mentioned methods indicate the presence of various NiFe (hydr)oxides with different phases on the NiFe foam surface. For the anodized NiFe foam at pH 7, the overpotential for the onset of OER and the activity at 1 mA/cm2 are recorded at 440 and 580 mV, respectively. In addition, the effects of anodization potentials and electrochemically active surface areas are discussed.