▎ 摘　　要

NOVELTY - A silica/graphene three-dimensional composite material comprises a three-dimensional graphene foam matrix and a silica/graphene composite uniformly dispersed on a substrate. The silica/graphene composite has core-shell structure with silica particles as a core and graphene as a casing. USE - Silica/graphene three-dimensional composite material used in pressure sensor (claimed). ADVANTAGE - The composite material has excellent mechanical strength, high force sensitivity, high electrical conductivity, high mechanical recovery, simple operation and low requirements on equipment. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of silica/graphene three-dimensional composite material, which involves (1) depositing graphene on a surface of the silica particles by chemical vapor deposition to obtain a silica/graphene composite, (2) adding the silica/graphene composite prepared in the step (1) to the graphene oxide dispersion to uniformly disperse the silica/graphene composite, adding reducing agent and buffering agent, and mixing, to obtain a reaction liquid, and transferring reaction liquid to a reaction vessel to obtain a hydrogel of a silica/graphene three-dimensional composite material, and removing the unreacted reducing agent and buffer in the hydrogel, (3) freezing hydrogel treated by the step (2) and placing in a freeze dryer to obtain an aerogel of a silica/graphene three-dimensional composite material, (4) annealing aerogel prepared in the step (3) under vacuum.