Controllable depolymerization of lignin using carbocatalyst graphene oxide under mild conditions

•Carbocatalyst graphene oxide depolymerizes lignin without an additional oxidizer under mild conditions.•Depolymerization is catalyzed via an oxidative mechanism through an enol-ether intermediate.•Phenolic OH prohibits ring open reaction from the enol ether intermediate.•Carbocatalyst graphene oxide is recyclable.