Electrocatalytic Activity of Nanocomposites of Sulphur Doped Graphene Oxide and Nanosized Cobalt Phthalocyanines

Abstract

In this work we explore the electrocatalytic activity of nanocomposites of reduced sulphur doped graphene oxide nanosheets (rSDGONS) and cobalt phthalocyanine (CoPc) or cobalt tetra amino phthalocyanine (CoTAPc) towards hydrogen peroxide. Transmission electron microscopy, scanning electron microscopy, X‐ray photon spectroscopy, X‐ray diffraction, chronoamperometry, linear scan voltammetry and cyclic voltammetry were used to characterize the nanocomposites. Nanosized CoPc showed superior (in terms of currents) electrocatalytic oxidation and reduction of hydrogen peroxide compared to CoTAPc nanoparticles (CoTAPcNP). The lowest detection limit was obtained for hydrogen peroxide oxidation on electrodes modified with CoPcNP‐rSDGONS at 1.49 µM. The same electrode gave a high adsorption equilibrium constant of 1.27×103 mol−1 and a Gibbs free energy of −17.71 kJ/mol, indicative of a spontaneous reaction on the electrode surface.

Electrochemical Detection of 4‐Chlorophenol Using Glassy Carbon Electrodes Modified with Thulium Double‐Decker Phthalocyanine Salts

“…5 which relates Gibbs free energy change due to adsorption (ΔG°) to the adsorption equilibrium constant β, ΔG° values were determined to be −18.79 kJ.mol −1 and −20.84 kJ. mol −1 for 2 a‐GCE and 2 b‐GCE , respectively and are comparable to those reported elsewhere for high Tafel slopes …”

“…The other vibrational characteristics of LnPc 2 complexes (2 a and 2 b) including C=C, C=N-and CÀ N from the benzene ring, azo and the isoindole groups were observed observed from 1356 to 1714 cm À 1 . The CH 3 and CÀ H vibrations on the diethylaminophenoxy or the benzene rings of the LnPc 2 cores in 2 a and 2 b, appeared at ∼ 2851 to 2964 cm À 1 .…”

“…mol À 1 for 2 a-GCE and 2 b-GCE, respectively and are comparable to those reported elsewhere for high Tafel slopes. [3,78]…”

“…Metallophthalocyanines (MPcs) are well known electrocatalysts. [1][2][3][4] It has been shown that, among the Pc derivatives, rare-earth based sandwich-type Pc (LnPc 2 ) derivatives have an additional interest for sensing applications due to their remarkable properties that are superior to those shown by other Pcs, [5] particularly as electrochemical sensors. [1,6,7] LnPc 2 complexes exhibit better electrochemical and electrochromic properties than their metallo monophthalocyanine (MPc) analogues.…”

Synthesis and effect of substituent position, metal type on the electrochemical properties of (3-morpholin-4-ylpropoxy) groups substituted cobalt, manganese phthalocyanines

“…Phthalocyanines and their derivatives have been used in many applications such as chemical and biosensor [3], solar cell, [4,5], catalyst [6], nonlinear optic [7], liquid crystal [8], catalyst [9,10], photosensitizers in photodynamic therapy (PDT) [11,12], because they have intense blue-green colour owing to the electronic delocalization of their 18π electrons. On the other hand, electrochemical characterization of phthalocyanines is important for the electrocatalyst [13], electrosensing [14], electropolymerization [15,16], electrochromic fields [17].…”