Electrodeposition of Manganese (III) Phthalocyanine/ Reduced Graphene Oxide for Asymmetric Supercapacitor Devices

In this study, two novel tetra-substituted manganese (III) phthalocyanines bearing (9H-carbazol-2-yl)oxy groups on peripheral (1) or non-peripheral (2) positions were prepared and used for modification of reduced graphene oxide (rGO) by applying a simple one-step electrodeposition technique for the first time. The manganese (III) phthalocyanines (MnPcs) were electropolymerized and graphene oxide was electrochemically converted into reduced graphene oxide simultaneously. Subsequently, an rGO-MnPc hybrid structure was formed directly on the NiF electrode (substrate) via layer-by-layer assembly. Additionally, the effect of substituent position on the charge storage capacity of the prepared hybrid capacitive candidates was investigated. The fabricated hybrid electrodes exhibited remarkable electrochemical performance due to the combination of manganese (III) phthalocyanines and reduced graphene oxide. The NiF/rGO₂-2 electrode exhibited the highest specific capacitance (512.4 F g^-1) at 0.5 A g^-1 and the remained specific capacitance was obtained 88.1 % after 5000 consecutive charge-discharge cycles. An asymmetric supercapacitor (ASC) was constructed from rGO₂-2 as the positive electrode and rGO as the negative electrode with a working potential of 1.5 V. The as-prepared device delivered a specific energy of 17.4 Wh kg^-1 at 350 W kg^-1. Hence, manganese (III) phthalocyanine-reduced graphene oxide electrodes can be considered outstanding materials for energy storage applications in the future.