Nanostructured Cobalt(II) Tetracarboxyphthalocyanine Complex Supported Within the MWCNT Frameworks: Electron Transport and Charge Storage Capabilities

Abstract

The electrochemical redox properties of a surface‐confined thin solid film of nanostructured cobalt(II) tetracarboxyphthalocyanine integrated with multiwalled carbon nanotube (nanoCoTCPc/MWCNT) have been investigated. This novel nanoCoTCPc/MWCNT material was characterized using SEM, TEM, zeta analysis and electrochemical methods. The nanoCoTCPc/MWCNT nanohybrid material exhibited an extra‐ordinarily high conductivity (15 mS cm−1), which is more than an order of magnitude greater than that of the MWCNT‐SO3H (527 µS cm−1) and three orders of a magnitude greater than the nanoCoTCPc (4.33 µS cm−1). The heterogeneous electron transfer rate constant decreases as follows: nanoCoTCPc/MWCNT (kapp≈19.73×10−3 cm s−1)>MWCNT‐SO3H (kapp≈11.63×10−3 cm s−1)>nanoCoTCPc (kapp≈1.09×10−3 cm s−1). The energy‐storage capability was typical of pseudocapacitive behaviour; at a current density of 10 µA cm−2, the pseudocapacitance decreases as nanoCoTCPc/MWCNT (3.71×10−4 F cm−2)>nanoCoTCPc (2.57×10−4 F cm−2)>MWCNT‐SO3H (2.28×10−4 F cm−2). The new nanoCoTCPc/MWCNT nanohybrid material promises to serve as a potential material for the fabrication of thin film electrocatalysts or energy‐storage devices.