Synthesis of nanostructured sphere-like copper oxide by microwave spray pyrolysis

•CuO/Cu2O submicrospheres were synthesized via microwave-assisted spray pyrolysis.•The entire process took only 20 min, without any further treatment.•The submicrospheres are composed of primary nanoparticles of 18 nm.•The material exhibited a bandgap of 1.28 eV.•The exhibited bandgap is often found in the literature for CuO.