- Title
- The effects of graphene and other nanomaterials on the electrocatalytic behaviour of phthalocyanines
- Creator
- Shumba, Munyaradzi
- Date Issued
- 2017
- Date
- 2017
- Type
- Thesis
- Type
- Doctoral
- Type
- PhD
- Identifier
- http://hdl.handle.net/10962/37952
- Identifier
- vital:24712
- Description
- Carbon based nanomaterials, gold nanorods and metallophthalocyanine nanoconjugates have been developed for electrocatalysis. Carbon based nanomaterials used are multiwalled carbon nanotubes, pristine graphene oxide nanosheets, nitrogen, boron, sulphur, phosphorus doped graphene oxide nanosheets. Cobalt phthalocyanine (CoPc), cobalt tetra aminophenoxy phthalocyanine (CoTAPc), cobalt tetra aminophenoxy phthalocyanine (CoTAPhPc), cobalt mono carboxyphenoxy phthalocyanine (CoMCPhPc) and cobalt tetra carboxyphenoxy phthalocyanine (CoTCPhPc) are the phthalocyanines employed in this work. Metallophthalocyanines were employed either in their bulk form or in their nanosized form. Electrode modification by these nanomaterials was either done sequentially, premixed or linked nanoconjugates. In all sequential modification, phthalocyanines were employed on top of other nanomaterials. Sequentially modified electrodes gave higher detection currents than both premixed and covalently bonded nanoconjugates. The nanomaterials reported here were characterised by transmission electron microscopy, Raman spectroscopy, time of flight secondary ion mass spectrometry, and X-ray diffraction among other techniques. The modified electrodes were further characterised by scanning electron microscopy, scanning electrochemical microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry, while square wave, linear scan and cyclic voltammetry, rotating disc electrode and chronoamperometry have been used to evaluate the electrocatalytic behaviour of the previously mentioned towards either oxidation or reduction of L-cysteine and/or hydrogen peroxide respectively. Generally, the nanoconjugates resulted in superior catalytic performance compared to the performance of individual nanomaterials. Zinc octacarboxy phthalocyanine (ZnOCPc) conjugated to either GONS or rGONS were employed to compare electrocatalytic detection of hydrogen peroxide to its luminescence sensing.
- Format
- 249 leaves
- Format
- Publisher
- Rhodes University
- Publisher
- Faculty of Science, Chemistry
- Language
- English
- Rights
- Shumba, Munyaradzi
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Collections
RU Department of Chemistry
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