A review of comprehensive utilization of biomass to synthesize carbon nanotubes: From chemical vapor deposition to microwave pyrolysis

Biomass is the only carbon-containing solid renewable resource with clean and environmentally friendly attributes, and is abundant and widely distributed in nature. It is a green source for advanced carbon materials. This review summarizes the important roles of carbon sources, catalysts and catalyst supports in the preparation of carbon nanotubes (CNTs) via chemical vapor deposition, as well as the mechanism for CNT growth and the raw material characteristics, preparation methods and formation mechanism for CNTs synthesized by microwave pyrolysis of biomass. Finally, the remaining problems in the current research and future work to be done are put forward with a view to realizing large-scale green preparation of biomass-based CNTs and resource utilization with biomass.