An excellent Fenton catalyst requires high activity, good stability and also convenience in separation for recycling. In this work we report Fenton-reaction-derived iron/nitrogen-doped graphene with encapsulated iron carbide nanoparticles (Fe3C@Fe/N-G) as an excellent heterogeneous Fenton catalyst. It was synthesized via Fe3+/H2O2-Fenton-reaction-driven oxidative polymerization of dopamine on graphene oxide surface, followed by carbonization process. Detailed characterizations unveil that as-prepared Fe3C@Fe/N-G is made up of Fe/N-doped graphene sheets with encapsulated dense and homogeneous Fe3C nanoparticles. Due to its unique microstructure and rationally-combined components, this catalyst exhibits appealing catalytic performance including high activity and excellent recoverability in photo-assisted Fenton reaction. This work may offer a valuable route to rational design and controllable synthesis of high-performance transition metal-based catalysts. [GRAPHICS] .