Self‐Supported Electrocatalysts Derived from Nickel‐Cobalt Modified Polyaniline Polymer for H2‐Evolution and O2‐Evolution Reactions

The water splitting aims to produce H2 for fuel cells and a number of industrial processes such as the ammonia synthesis and the metals refining. There is actually a major limitation about the development of cost-effective and efficient electrocatalysts to lower the cell voltage that must be overcome to perform sequentially the overall reaction that is 2H2O → 2H2 + O2. In the present study, we combined Ni and Co as the promising alternative catalytic metals to Pt-group metals as well as N and S as the doping elements to fabricate self-supported electrocatalysts for hydrogen evolution (HER) and oxygen evolution (OER) in alkaline media. To these ends, the polymerization of the aniline into polyaniline (PANI) in the presence of Ni(II) and Co(II) followed by calcination in air resulted in the formation of heterogeneous catalytic materials self-supported onto a matrix made of C, N, S, Ni and Co. Enhanced activity and durability were recorded for the hybrid and bimetallic PANI-NiCo composite.