Nanoparticles of CuGaO2 delafossite were successfully synthesized from the sol – gel process by controlling the atmospheric conditions at 850 oC. 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 oC and 1200 oC in nitrogen and air atmosphere, respectively, while our methodology stabilizes the CuGaO2 particles in the nano-metric region at low temperature (i.e. 850 oC).

Ultrafine iridium oxide nanorods (IrO2 NRs) were successfully synthesized using a molten salt method at 650 _C. The structural and morphological characterizations of these IrO2 NRs were carried out by powder X-ray diffraction, Raman spectroscopy and electron microscopic techniques.

Delafossite CuGaO2 has been employed as photocatalysts for solar cells, but their electrocatalytic properties have not been extensively studied, especially no comparison among samples made by different synthesis routes. Herein, we first reported the successful synthesis of delafossite CuGaO2 particles with three different morphologies, i.e. nanocrystalline hexagons, sub-micron sized plates and micron–sized particles by a modified hydrothermal method at 190°C for 60 h,1,2,3 a sono-chemical method followed by firing at 850°C for 48 h, and a solid state route at 1150°C, respectively.