High-Performance NiO/GCN Nanohybrids Synthesized under Different Thermal Conditions for Efficient Electrocatalytic Oxygen Evolution Reaction

Abstract

Advancements in renewable energy technologies heavily depend on effective electrocatalysis, and the exploration of hybrid nanomaterials shows great potential for achieving improved catalytic performance. This research delves into the synthesis and characterization of nanohybrids incorporating graphitic carbon nitride (GCN) and nickel oxide (NiO) under varying thermal conditions for the oxygen evolution reaction (OER). A coprecipitation method produced the nanocomposite, analyzed through various characterization techniques. NiO/ GCN nanohybrids synthesized at lower temperatures displayed superior activity, attributed to the well-defined biotite and muscovite structure promoting efficient charge transfer. Higher temperatures synthesized nanohybrids led to reduced efficiency due to agglomeration-induced restricted active site accessibility. NiO/ GCN at 400 °C composite exhibited outstanding electrocatalytic activity with low overpotential, high current density, and durability. In a 24 h chronoamperometry study, the glassy carbon (GC) modified NiO/GCN electrode demonstrated commendable durability, requiring only 261 mV overpotential for a current density of 10 mA/cm 2 and a modest Tafel slope of 69.62 mV decade.