▎ 摘　　要

NOVELTY - Preparation of graphene oxide composite, involves mixing graphene oxide and water to obtain a dispersion, soaking cotton thread in the dispersion for 0.5-10 hours, and drying at 30-80 degrees C for 10-20 hours. USE - Preparation of graphene oxide composite for forming filter layers of filter cores used for adsorbing heavy metal ions in water (all claimed). ADVANTAGE - The method enables uniform loading of graphene oxide on the surface and internal voids of cotton thread, and combines graphene oxide and cotton thread together by Van der Waals force to form a three-dimensional structure. Cotton thread has excellent mechanical strength and stability, thus enabling effective use of the composite as filter layer of filter core. Since there is no omission of graphene oxide from cotton thread, the filter core can be used repeatedly. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) graphene oxide composite comprising graphene oxide loaded on the surface of cotton thread; and (2) graphene oxide filter core comprising a framework, and a filter layer formed by winding the composite, arranged on the outer surface of framework.