rGO/PEDOT:PSS/NiMn2O4 Nanohybrid: An Inexpensive Anode Catalyst for Methanol and Ethylene Glycol Electro-Oxidation

Abstract

Present work reports the development of a mesoporous ternary nanohybrid (GPN) based on NiMn2O4, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and reduced graphene oxide (rGO) for methanol (MeOH) and ethylene glycol (EG) oxidation. Initially, NiMn2O4 nanoparticles have been synthesized using solvothermal-assisted calcination and then polymerization of EDOT monomer has been done in presence of rGO nanosheets and NiMn2O4 nanoparticles to form GPN nanohybrid. The current densities of 70.4 mA cm−2 at an onset potential of 0.21 V in 0.5 M MeOH and 53 mA cm−2 at an onset potential of 0.32 V in 0.5 M EG solution have been recorded at GPN modified indium tin oxide (ITO) electrode. This electrode exhibits a current retention of 87% in 0.5 M MeOH and 81% in 0.5 M EG solution after 700 cycles. The improved electrocatalytic activity and cyclic stability of GPN can be attributed to the presence of rich binary active sites of Ni and Mn species, large surface area and high electrical conductivity of rGO and uniform dispersion of NiMn2O4 nanoparticles over PEDOT:PSS. This work demonstrates the potential of GPN nanohybrid as an alternative to platinum towards MeOH and EG electro-oxidation.