▎ 摘　　要

Graphene sheets have been synthesized from single walled carbon nanohorns by one-step reaction with hydrogen peroxide. The obtained graphene sheets are in pure form and shows good electrical properties. As-synthesized graphene acts as dual function of support as well as reducing agent to prepare graphene-silver nanoparticle composite having uniform particle size of 6 nm. This method can easily be scalable to prepare graphene or graphene supported metal nanoparticle composites for versatile applications.