Microwave irradiation on carbon black: Studies on the transformation of particles into nano-balls, nano-sticks and nano-onion like structures

Abstract The solid-state transformation behavior of carbon black (CB) nanoparticles after irradiated with microwave energy was studied with and without influence of a metal catalyst. The CB sample was exposed to microwave radiation at power of 900 W from the oven and collected after 15 min and after 30 min and 45 min of irradiation. The samples were characterized using X-ray diffraction measurements, Raman spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM) and thermogravimetric analysis. Characterization of the samples prepared without catalyst shows that microwave irradiation can transform CB nanoparticles into nano–balls and nano–stick like structures. While nanoballs of almost 300–500 nm diameter are visible in all the samples irrespective of microwave irradiation time, amorphous nano-stick like structure are present only in the sample collected after 30 min of microwave irradiation. CB irradiated together with a metal catalyst resulted in metal-encapsulated onion like structures with perfectly arranged graphene layers.