▎ 摘　　要

NOVELTY - Composite material comprises graphene oxide and sheet-like magnesium hydroxide having one-dimensional size of 20-500 nm. The sheet-like magnesium hydroxide is uniformly dispersed on the surface of the graphene oxide. USE - Composite material is useful in flame retardant and water treatment (claimed). ADVANTAGE - The composite material avoids the agglomeration of graphene oxide and can be simply, rapidly and efficiently prepared in an large-scale industrial manner. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the method for preparing the composite material, which involves preparing graphene oxide by adopting a Hummers method, subjecting the graphene oxide to drying and dispersing to obtain graphene oxide dispersion liquid, preparing magnesium salt solution, preparing an alkali solution, adding the graphene oxide dispersion liquid to a hypergravity rotary packed bed or a sleeve type micro-channel reactor, adding magnesium salt solutions and the alkali solution, reacting to obtain a crude product, washing and drying the crude product to obtain the magnesium hydroxide/graphene oxide composite material.