▎ 摘　　要

Direct growth of graphene film on dielectric substrates is significant for the applications in electronic devices, which can avoid additional complicated and damaging treatments. Despite the advances, a facile way is urgently required to prepare graphene directly on insulators at a low temperature. We presented a gallium (Ga)-assisted atmosphere chemical vapor deposition to synthesize graphene films on silicon nitride (Si3N4). Liquid Ga was dropped on the substrate as a catalyst and flowed away after growth, achieving graphene on Si3N4 (100 nm)/SiO2 (100 nm)/Si and recovering the most of Ga. Multilayer graphene film was formed at the interface between Ga and the substrate. The growth of graphene was investigated by regulating the growth conditions, and an interfacial precipitation mechanism was proposed. Graphene synthesized with recovered Ga droplet is comparable to that prepared using pure Ga, revealing the reusability of Ga catalysts.