▎ 摘　　要

NOVELTY - A graphene fiber has uniform diameter and size distribution, and a surface having parallel directional gully structure, analyzed by combination of atomic force microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and electrochemical workstation linear voltammetry scanning. The gully size and conductivity can be controlled by changing the size of graphene oxide sheet precursor. The graphene oxide nanosheet has a thickness of 1 nm and size of 2.12-9.22 mu m. The gully size is 0.81-1.73 mu m. The conductivity is 345.58-443.41 S/m. USE - Graphene fiber used in energy storage and conversion applications, biomedical applications, environmental protection applications, and multifunctional materials. ADVANTAGE - The graphene fiber can be prepared by simple and economical method, with excellent repeatability, using little amount of impurities, and to provide controllable conductivity and regular gully patterns on graphene fiber surface, without using reducing agents, binders, and other conductive materials. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the graphene fibers, which involves preparing a graphite oxide colloid using a modified Hummers method, ultrasonically dispersing 5-12 mg/mL graphite oxide colloid in ultrapure water at 50-500 W for 20-100 minutes, obtaining a uniformly mixed graphene oxide colloid, injecting the graphene oxide colloid into a capillary having a diameter of 0.2-1.2 mm, by a syringe, closing the capillary, hydrothermally reacting at 150-300 degrees C for 30-480 minutes, and drying in a glass tube at room temperature.