Gas-driven shearing nanonization of lignin particles for efficient reduction of graphene oxide

Lignin, the second most abundant biopolymer after cellulose, is a promising but still underutilized natural reductant. Nanonization of the bulk lignin into nanoparticles provides a versatile option to enhance its reduction ability by enlarging the specific surface area and making more functional groups exposed to surface. In this work, a novel and simple gas-driven shearing nanonization method with mild operation conditions was explored for green preparation of lignin nanoparticles (LNs). LNs with an average size of ~120 nm were prepared under the working pressure as low as 0.5 MPa. The reduction ability of the as-prepared LNs was investigated by reducing graphene oxide (GO) into graphene. The results indicated that the preparation of LNs could effectively enhance the reduction ability of lignin when compared with the raw lignin. The gas-driven shearing nanonization method offers a green and simple alternative to produce LNs with high-value application prospects.