Self-assembled CoSe2–FeSe2 heteronanoparticles along the carbon nanotube network for boosted oxygen evolution reaction

Abstract

Water electrolysis is a significant alternative technique to produce clean hydrogen fuel in order to replace environmentally destructive fossil fuel combustion. However, the sluggish oxygen evolution kinetics makes this process vulnerable as it requires relatively high overpotentials. Hence, significantly effective electrocatalysts are necessary to access the water-oxidation process at a low overpotential to make this process industrially viable. Therefore, in order to reduce the energy barrier, we developed bimetallic CoSe₂–FeSe₂ heteronanoparticles along the carbon nanotube network (CoSe₂–FeSe₂/CNT) via a facile selenization strategy. Due to the unique assembly of highly conductive nanoparticles along the CNT network, the CoSe₂–FeSe₂/CNT displays an exceptionally good oxygen evolution (OER) activity; it requires 248 mV overpotential to reach a current density of 10 mA cm⁻² (η₁₀) with an ultra-low Tafel slope of 36 mV dec⁻¹ and displays an overpotential of 1.59 V (η₁₀) in the full water-splitting catalysis with the commercial Pt/C cathode. The high OER activity of CoSe₂–FeSe₂/CNT over the monometallic CoSe₂/CNT and FeSe₂/CNT electrocatalysts approve the synergistic interactions. Therefore, the superior performance is possibly ascribed to the unique porous nanoarchitecture and the strong coupling interactions between CoSe₂ and FeSe₂ heteronanoparticles on the conductive network. This study introduces an innovative approach to rationally design and fabricate cost-effective and highly proficient electrocatalysts for boosted OER performance.