Oxygen Plasma Activation of Carbon Nanotubes-Interconnected Prussian Blue Analogue for Oxygen Evolution Reaction

To obtain renewable and clean fuels, exploration of effective electrocatalysts is highly desirable due to the sluggish kinetics of water splitting. In this study, the oxygen plasma-activated hybrid structure of Ni–Fe Prussian blue analogue (PBA) interconnected by carbon nanotubes (O–CNT/NiFe) is reported as a highly effective electrocatalytic material for the oxygen evolution reaction (OER). The electrocatalytic performance is significantly influenced by different mass ratios of CNTs to Ni–Fe PBA. Benefiting from the conductive and oxygen plasma-activated CNTs as well as ordered and distributed metal sites in the framework, the optimized O–CNT/NiFe 1:18 exhibits a competitive overpotential of 279 mV at a current density of 10 mA cm–2 and a low Tafel slope of 42.8 mV dec–1 in 1.0 M KOH. Furthermore, the composite shows superior durability for at least 100 h. These results suggest that the O–CNT/NiFe 1:18 possesses promising potential as a highly active electrocatalyst.