Boosting the Capacitive Performance of Cobalt(II) Phthalocyanine by Non-peripheral Octamethyl Substitution for Supercapacitors

Main observation and conclusion In this paper, pristine cobalt(II) phthalocyanine (CoPc) and non-peripheral octamethyl substituted CoPc (N-CoMe2Pc) are the focus of electrochemical investigation. CoPc and N-CoMe2Pc nanorods (NR) were synthesized by a facile precipitation process from sublimated bulk phthalocyanine powders and their electrochemical properties were explored. Due to the large specific surface area, the capacitance performance of the nanorods was significantly higher than that of the sublimated powder sample. N-CoMe2Pc powder exhibited better pseudocapacity compared with CoPc powder and CoPc NR, which is attributed to enhanced charge transfer rate and improved redox activity after the introduction of octamethyl substituents on phthalocyanine ring. The maximum specific capacitance value was achieved by N-CoMe2Pc NR based electrode, exhibiting 210.2 F g(-1) capacitance at 5 mV s(-1) scan rate and 156.1 F g(-1) at 0.25 A g(-1) current density, and also showing high efficiency and satisfactory retention. These results indicate that according to proper molecular design, N-CoMe2Pc NR could be applied as the potential candidate for electrode material in supercapacitors. [GRAPHICS] .