In this manuscript, we report a one-step, all solid-state microwave procedure for simultaneous reduction, nitrogen-doping and concurrent growth of carbon nanotube ‘spacers’ on graphene from a single sustainable precursor, namely urea. Our newly developed technique not only effectively reduces graphene oxide but also results in growth of vertically anchored nitrogen doped carbon nanotubes on graphene substrate to give unique mesoporous, hierarchical, 3D nano-architectures. The utility of our newly developed G-NCNT in energy storage applications such as lithium-ion batteries and super-capacitors will also be reported. ^**This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2011-0030013, 2016R1A2B1013276).