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-yloxy groups on peripheral or non-peripheral positions were prepared and used for modification of reduced graphene oxide by applying a simple one-step electrodeposition technique for the first time. The manganese (III) phthalocyanines (1 and 2) 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.

Supercapacitive properties of carbazole-containing cobalt(II) phthalocyanines/reduced graphene oxide composites.

This study aims to compare the effect of substituents (position and number) and reduced graphene oxide on the supercapacitive properties of cobalt(II) phthalocyanines. For this purpose, three new tetra- and octa-substituted cobalt(II) phthalocyanines bearing 9H-carbazol-2-yloxy groups on peripheral or non-peripheral positions (1-3) were synthesized. The characterization of the resultant cobalt(II) phthalocyanines was carried out by applying several spectroscopic approaches. The newly synthesized macromolecules were used for the functionalization of reduced graphene oxide (rGO). The obtained nanocomposites (rGO-(1-3)) were utilized for the modification of Ni foam (NiF) electrodes through a facile one-step electrodeposition strategy performed for electrochemical supercapacitor applications. Simultaneous polymerization of the cobalt phthalocyanines and electrochemically reduction of graphene oxide led to the formation of a fabricating layer on the surface of the NiF electrode. The resulting electropolymerized films were characterized by Raman, Fourier-transform infrared (FT-IR), and Field emission scanning electron microscope (FESEM) spectroscopic techniques as well as electrochemical methods. The prepared electrodes possessed superior electrochemical activities owing to the synergistic effect of the cobalt(II) phthalocyanines and rGO. All the modified electrodes displayed high supercapacitaive properties and the highest activity was obtained for the NiF/rGO2-1 electrode. The NiF/rGO2-1 electrode exhibited higher specific capacitance (655.2 F g-1 at 0.5 A g-1) than NiF/1 (338.0 F g-1). Additionally, a specific capacitance of 85.2% was obtained for NiF/rGO2-1 electrode after 3000 charge-discharge cycles. As a result, all the prepared metallophthalocyanines-reduced graphene oxide can be considered alternative agents to develop high performance-next-generation energy storage devices.