Some embodiments are directed to a method and device for reducing a component composed of at least one graphene oxide and a matrix consisting of at least one polymer, characterized in that the method includes at least the following steps: introducing a mixture of polymer(s) and graphene oxide GO into a reactor subject to a value of temperature T and a value of pressure P suitable for placing a fluid under supercritical or subcritical conditions for a given period, the temperature T being suitable for not degrading the polymer; and cooling the reactor and removing the obtained product R consisting of reduced polymer(s) and graphene oxide rGO.