▎ 摘　　要

NOVELTY - The preparation method of graphene involves mixing magnesium and calcium carbonate powder, pulverizing, evenly spreading powder over bottom of portion of quartz tube, placing quartz tube in horizontal high-temperature tube furnace, evacuating furnace, heating, cooling to obtain gray powder, adding hydrochloric acid solution, reacting, washing, solid-liquid separating, and drying solid product. USE - Preparation of graphene (claimed). ADVANTAGE - The method enables preparation of graphene with improved purity in a simple, energy-efficient, economical and environmentally-friendly manner. DETAILED DESCRIPTION - The preparation method of graphene involves mixing magnesium and calcium carbonate powder for 30 minutes, pulverizing into powder, evenly spreading powder over bottom portion of a quartz tube, placing quartz tube in a horizontal high-temperature tube furnace, evacuating high-temperature tube furnace with a vacuum pump so as to ensure air tightness in the furnace, heating furnace at 850 degrees C for 30 minutes to 5 hours in the presence of 60 ml/minute-1 argon gas, cooling to room temperature to obtain gray powder, adding 3mol/l hydrochloric acid solution to gray powder and then stirring, reacting for 120 minutes, washing mixture with distilled water until mixture is neutralized, solid-liquid separating, and drying solid product at 25 degrees C for 24 hours under vacuum conditions.