Ceria Supported Nickel(0) Nanoparticles: A Highly Active and Low Cost Electrocatalyst for Hydrogen Evolution Reaction

Herein, we report the development of a nickel-based catalyst obtained by reduction of Ni2+ ions on the surface of ceria nanopowder using aqueous solution of NaBH4. The catalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). Nickel(0) nanoparticles supported on nanoceria (Ni0/CeO2) were employed as electrocatalyst on glassy carbon electrode (GCE) for H2 evolution reaction. The modified Ni0/CeO2-GCE requires a relatively small overpotentials of 150 mV, 175 mV and 203 mV to drive current densities of 10, 20 and 50 mA cm−2, respectively. Tafel slope, 80 mV dec−1, indicates that HER process follows the Volmer-Heyrovsky mechanism with relatively high turnover frequency (TOF), i.e. 0.41 and 5.84 s−1 at an overpotential of 100 and 200 mV, respectively. A drastic enhancement in the electrocatalytic activity of Ni0/CeO2-GCE was observed when platinum wire was used as counter electrode instead of graphite rod, especially after long term potential cycling due to platinum dissolution and deposition on the modified electrode. Ni0/CeO2-GCE was found to exhibit high electrochemical stability (i.e. a small change both in the Tafel slope and onset potential) after 2000 CV scans in 0.5 M H2SO4, which makes Ni0/CeO2 a potential electrocatalyst for H2 evolution from water.