▎ 摘　　要

NOVELTY - Preparation of graphene nano-material comprises mixing catalytic agent, magnesium oxide and deionized water to obtain slurry, spray granulating, drying, and calcining to obtain an enriched material having a particle diameter of 10-100 mu m and specific surface area of 50-200 m2 g as magnesium oxide carrier of active material; and heating to 600-900 degrees C under an inert gas atmosphere and subjecting to chemical vapor deposition reaction by introducing a multi-carbon cracking gas for 3 hours. USE - Method for preparing graphene nano-material used for preparing concrete material (claimed). ADVANTAGE - The nano-material has high specific surface area and improves intensity, toughness, and water resistance of concrete. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of modified nanographene material comprising mixing graphene nano-material and silicate at weight ratio of 1:3-4, stirring with deionized water at ratio of 1:4-5, heating to 150-170 degrees C and 0.6-0.8 MPa, and hydrothermal reacting for 2-4 hours.