Carbon nanotubes/graphene/nickel (CNT-G-Ni) fluffy spheres were synthesized using renewable carbon sources. Carbon-encapsulated nickel nanoparticles (CENNs) were prepared by hydrothermal carbonization (HTC) of potato starch and nickel nitrate, and then followed by catalytic graphitization at 900 degrees C. The prepared GENNs were cracked at 700 degrees C in biogas, during which graphene shells over GENNs were peeled off and formed graphene nanoplatelets, and simultaneously multiwall carbon nanotubes (MWCNTs) were formed over nickel particles and in-situ integrated into graphene nanoplatelets t...
