▎ 摘　　要

NOVELTY - Manufacturing alumina nano-sheet, comprises (a) mixing by dispersing graphene oxide and alumina precursor in non-aqueous solvent, (b) hydrolyzing alumina precursor by adding aqueous medium into the obtained mixed solution, (c) producing alumina-graphene oxide composite by drying the hydrolyzed mixture, and (d) thermally decomposing the obtained composite at 500-800 degrees C using stream of air. USE - The nano-sheet is useful for removing heavy metals or valuable metals (claimed). ADVANTAGE - The nano-sheet has excellent arsenic removal capacity, large surface area and pore volume; and can be produce in bulk amount in an easy manner using graphene oxide template. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) alumina nano-sheet prepared by the above method; and (2) removing heavy metals or valuable metals, comprising applying the alumina nano-sheet on a substance containing heavy metals or valuable metals.