Effect of nature of nanoparticles on the photophysicochemical properties of asymmetrically substituted Zn phthalocyanines
- Authors: Magadla, Aviwe , Oluwole, David O , Britton, Jonathan , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234539 , vital:50206 , xlink:href="https://doi.org/10.1016/j.ica.2018.06.043"
- Description: In this work, low symmetry Zn mono caffeic acid tri-tert butyl (1) and Zn monocarboxyphenoxy tri-(tert-butylphenoxyl) (2) phthalocyanines (Pcs) were covalently linked to amino (using glutathione, GSH, or 3-aminopropyl)triethoxysilane, APTES) functionalised nanoparticles. The nanoparticles are represented as: AgNPs-GSH, SiNPs-APTES, Fe3O4-Ag-SiNPs-APTES and Fe3O4-AgNPs-GSH). The photophysical and photochemical behaviour of the complexes 1 and 2 and their conjugates with nanoparticles were investigated in dimethyl sulfoxide. The conjugates of the Pc complexes with the NPs afforded increase in triplet quantum yields with corresponding decrease in fluorescence quantum yield compared to the Pc complexes alone. The conjugates of 1-AgNPs-GSH, 2-SiNPs-APTES and 2-Fe3O4-Ag-SiNPs-APTES showed higher singlet oxygen quantum yield values as compared to the Pc complexes alone.
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- Date Issued: 2018
Optimizing phthalocyanine based dye-sensitized solar cells: The role of reduced graphene oxide
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Fomo, Gertrude , Oluwole, David O , Sindelo, Azole , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187770 , vital:44695 , xlink:href="https://doi.org/10.1016/j.synthmet.2018.10.021"
- Description: Dye-sensitized solar cells (DSSC) were fabricated by incorporating graphene materials as catalysts at the counter electrode. Platinum was also used as a catalyst for comparison purposes. Different phthalocyanines: hydroxyl indium tetracarboxyphenoxy phthalocyanine (1), chloro indium octacarboxy phthalocyanine (2) and dibenzoic acid silicon phthalocyanine (3) were used as dyes. Complex 3 gave the highest power conversion efficiency (η) of 3.19% when using nitrogen doped reduced graphene oxide nanosheets (NrGONS) as a catalyst at the counter electrode, and TiO2 containing rGONS at the anode. The value is close to 3.8% obtained when using Pt catalyst instead of NrGONS at the cathode, thus confirming that NrGONS is a promising candidate to replace the more expensive Pt. The study also shows that placing rGONS on both the anode and cathode improves efficiency.
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- Date Issued: 2018