One-step synthesis of porous copper oxide for electrochemical hydrogen evolution

Electrochemical hydrogen production offers an efficient means of utilizing renewable energy for generating hydrogen. Copper oxide is important in forming cathode electrodes for water splitting cells. The present study focuses on synthesizing porous copper oxide via thermal oxidation using copper salt and melamine as precursors. By adjusting the melamine content in the copper salt, it becomes possible to customize the phase, morphology, and porosity of the resultant copper oxide. The synthesized material is characterized using XRD, SEM, TEM and XPS. Copper oxide (Cu x O) deposited on nickel foam is tested via linear sweep voltametry (LSV) for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The overpotential for HER process for non-porous, porous pure phase and mixed phase porous Cu x O is same i.e. 46 mV for current density of 10 mA cm −2 in 1 M KOH electrolyte. The Tafel slope is 256.29 mV/dec, 254.3 mV/dec and 114.05 mV/dec respectively for non-porous, pure phase porous and mixed phase porous Cu x O indicating efficient hydrogen evolution. The charge transfer resistance R ct value is 3.745 Ω, 0.321 Ω and 0.568 Ω respectively. The mixed phase Cu x O catalyst exhibited better stability as compare to the other for about more than 4 h.