▎ 摘　　要

A Grignard reagent, n-BuMgCl, is found to be able to reduce graphite oxide to form loosely aggregated graphene sheets immobilized with few MgCl species. Further complexing with TiCl4 leads to a graphene-based supported catalyst that is ready for in situ olefin polymerization to access electrically conductive polyolefin/graphene nanocomposites. PP/graphene nanocomposites thus prepared possess a rather low electrical percolation threshold (approximately 0.2 vol%) and high conductivities (e.g., 3.92 S.m-1 at 1.2 vol%, 28.5 S.m-1 at 4.1 vol%, and 163.1 S.m-1 at 10.2 vol%).