Regulated Bimetal-Doped Polyaniline: Amorphous-Crumple-Structured Viable Electrocatalyst for an Efficient Oxygen Evolution Reaction
Venkatachalam Ashok, Selvam Mathi, Muthukumaran Sangamithirai, Jayaraman Jayabharathi
Abstract
Development of inexpensive high-performance electrocatalysts for the oxygen evolution reaction becomes vital by altering a renewable source to hydrogen fuel generation. Here, we report the controlled ratio of inexpensive bimetal-doped polyaniline (Co4Ni1@PANI), a crumpled amorphous nanoparticle electrocatalyst synthesized by the solvothermal technique. PANI provides even distribution of bimetal nanoparticles, which prevents agglomeration and aids in lowering the charge transfer resistance to 4.2 Ω for Co4Ni1@PANI. As-synthesized Co4Ni1@PANI/GC exhibits low overpotential of 285 mV at 10 mA cm–2, low Tafel slope of 64 mV dec–1, and higher current density than precious IrO2 (η, 392 mV; Tafel slope, 97 mV dec–1). Co4Ni1@PANI has 3-fold higher turnover frequency (0.0249 s–1) than IrO2 (0.0077 S–1). Co4Ni1@PANI/NF at 10 mA cm–2 exhibits prolonged stability of 300 h for O2 evolution with <3.6% potential loss at 1.58 V cell potential. At 1.57 V, the solar-focused water electrolysis corroboration reinforces the efficacy of a new Co4Ni1@PANI electrocatalyst to hydrogen gas conversion. The current research findings confirmed that non-precious, low-cost Co4Ni1@PANI can be used for large-scale H2 production.