The present disclosure provides a preparation method of a plasma-treated nanofiber-based hydrogen gas sensing material, including the following steps: (1) stirring a mixed solution of absolute ethanol, polyvinyl pyrrolidone (PVP), N,N-dimethylformamide, SnCl.sub.2.Math.H.sub.2O, and Zn(CH.sub.3COO).sub.2.Math.2H.sub.2O uniformly on a constant-temperature magnetic stirrer to obtain a spinning solution; (2) electrospinning the spinning solution and depositing on an aluminum foil to obtain a spinning fiber; (3) annealing the spinning fiber in a muffle furnace to obtain a hydrogen gas sensing material sample; and (4) subjecting the hydrogen gas sensing material sample to a vacuum argon plasma treatment with a Hall ion source to obtain the nanofiber-based hydrogen gas sensing material. In the method, nanofibers are prepared by electrospinning and subjected to the vacuum argon plasma treatment through the Hall ion source. The prepared sensing material has an extremely large specific surface area, and gas-sensing properties of rapid response and high sensitivity to hydrogen gas.

Described are precursor fibers of lignin-based carbon fibers with a content of water-soluble lignin salt (A). A special characteristic of these precursor fibers is the inclusion of water-soluble polyvinylpyrrolidone or a derivative (B) thereof. Further described is an advantageous process for producing these precursor fibers as well as their advantageous use for producing carbon fibers by carbonization, optionally followed by graphitization.

Described are precursor fibers of lignin-based carbon fibers with a content of water-soluble lignin salt (A). A special characteristic of these precursor fibers is the inclusion of water-soluble polyvinylpyrrolidone or a derivative (B) thereof. Further described is an advantageous process for producing these precursor fibers as well as their advantageous use for producing carbon fibers by carbonization, optionally followed by graphitization.