Low-Temperature Carbonization of Phosphorus-Doped Nanocellulose for Carbon Nanofiber Film Fabrication

Nanocellulose extracted from agro-waste rice straw has been utilized to fabricate carbon nanofiber films. The nanocellulose-based films were drop-casted and underwent a two-step thermal treatment: stabilization at 180 degrees C in air and carbonization at 700 degrees C in a nitrogen atmosphere. Phosphoric acid (PA) was incorporated into the nanocellulose solution, resulting in a 17% reduction in stabilization activation energy and a 20% increase in carbonization yield. Additionally, PA facilitated phosphorus doping, leading to a phosphorus concentration of up to 5%, and enhanced the Brunauer-Emmett-Teller (BET) surface area from 223 m2 g-1 to 334 m2 g-1. Structural analysis via XRD, Raman spectroscopy, and TEM confirmed the formation of a turbostratic graphitic structure in the PA-doped carbon nanofiber films. This increased surface area and graphitic structure make the films highly promising for diverse applications, including flame-retardant coatings, sensors, energy storage devices, and biomedical uses.