Sol – gel synthesis, structural characterization and bifunctional catalytic activity of nanocrystalline delafossite CuGaO2 particles

Abstract

Nanoparticles of CuGaO2 delafossite were successfully synthesized from the sol – gel process by controlling the atmospheric conditions at 850 °C. The average size of CuGaO2 nanoparticles of ∼40 nm was determined by transmission electron microscopy. Note that the thermodynamically stable conditions for CuGaO2 delafossite synthesis are 1100 °C and 1200 °C in nitrogen and air atmosphere, respectively, while our methodology stabilizes the CuGaO2 particles in the nano-metric region at low temperature (i.e. 850 °C). Moreover, delafossites CuGaO2 nanoparticles show very interesting bifunctional catalytic activity in the electrolysis of water with O2 and H2 generation at anodic and cathodic potentials respectively. The current densities of CuGaO2 nanoparticles as the bifunctional catalysts were found to be 15 mA/cm2 and 18 mA/cm2 for H2 and O2 generation, respectively, using 0.5 M KOH solution as an electrolyte versus Ag/AgCl electrode.