The effects of carbon nanotubes on the electrocatalysis of hydrogen peroxide by metallo-phthalocyanines |
| |
Authors: | Mashazi Philani Mugadza Tawanda Sosibo Ndabenhle Mdluli Phumlani Vilakazi Sibulelo Nyokong Tebello |
| |
Institution: | a Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa b Nanotechnology Innovation Centre - Sensors, Chemistry Department, Rhodes University, PO Box 94, Grahamstown 6140, South Africa |
| |
Abstract: | The pre-grafted screen-printed gold electrode modified with phenyl-amino monolayer was investigated for covalent immobilization of phenyl-amine functionalized single-walled carbon nanotubes (PA-SWCNT) and metal tetra-amino phthalocyanine (MTAPc) using Schiff-base reactions with benzene-1,4-dicarbaldehyde (BDCA) as cross-linker. The PA-SWCNT and MTAPc modified electrodes were applied as hybrids for electrochemical sensing of H2O2. The step-by-step fabrication of the electrode was followed using electrochemistry, impedance spectroscopy, scanning electron microscopy and Raman spectroscopy and all these techniques confirmed the fabrication and the immobilization of PA-SWCNT, MnTAPc and CoTAPc onto gold surfaces. The apparent electron transfer constant (kapp) showed that the carbon nanotubes and metallo-phthalocyanines hybrids possess good electron transfer properties compared to the bare, pre-grafted and the MTAPc modified gold electrode surfaces without PA-SWCNT. The electrochemical sensing of hydrogen peroxide was successful with PA-SWCNT-MTAPc hybrid systems showing higher electrocatalytic currents compared to the other electrodes. The analytical parameters obtained using chronoamperometry gave good linearity at H2O2 concentrations ranging from 1.0 to 30.0 μmol L−1. The values for the limit of detection (LoD) were found to be of the orders of 10−7 M using the 3δ for all the electrodes. The PA-SWCNT-MTAPc modified SPAuEs were much more sensitive compared to PA-MTAPc modified SPAuEs. |
| |
Keywords: | Single-wall carbon nanotubes Metal tetra-amino phthalocyanine Electroanalysis Hydrogen peroxide |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|