Thesis (Ph. D.)--University of New South Wales, 2000. / Also available online.

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisors: Chin-Pao Huang, Dept. of Civil and Environmental Engineering, and S. Ismat Shah, Dept. of Materials Science Includes bibliographical references.

Thesis (M.Sc. (Chemistry)) - Rhodes University, 2008

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 72-74). Also available on the Internet.

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Chin-Pao Huang and Daniel K. Cha, Dept. of Civil & Environmental Engineering. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 72-74). Also available on the Internet.

Thesis (D.E.)--Lamar University-Beaumont, 2003. / Includes bibliographical references.

Organic donor and acceptor have promised the better future energy technologies to alleviate global energy demand and environmental issues. And nowadays they begin to come true in bulk heterojunction organic solar cells (BHJ OSCs) with advantages of low-cost, light-weight, large-area, flexibility, and with high efficiencies (PCEs) of over 14% for converting solar energy to electricity. Porphyrins are unique potential for artificial photocatalysis but their application in BHJ OSCs are still limited by the PCEs less than 10%. This complicacy comes from their inadequate spectral absorptions and the imperfect morphologies. In this thesis, we devote to chemical modification of acceptor-π-porphyrin-π-acceptor (A-π-Por-π-A) structural molecules to enhance their spectral absorptions and phase-separation functions with fullerene acceptor. Firstly, chemically driving J-aggregates have been studied on the new A-π-Por-π-A porphyrin molecule, which could improve the phase-separation of its blend film with PC71BM and and enhance its performance in BHJ OSCs with PCE up to 8.04%. Secondly, two new benzodithiophene (BDT) π-bridged A-π-Por-π-A molecules have been prepared with complementary absorption between the Soret and Q bands. The devices based on the blend fims of the porphyrin donor and PC71BM acceptor exhibit full spectral photocurrent generation and impressive PCEs up to 7.92%. Thirdly, we further extended the π-conjugation of the above BDT π-brigded A-π-Por-π-A molecules by inserting alkyl chain substituted thiophene derivatives into their backbones, resulting in new porphyrin molecules with UV-visible-near-infraed absorption spectra. Using those porphyrin molecules as donor and PCBM as acceptor, the devices show full spectra photocurrent generatoion and appropriate film morphology, resulting in high PCE up to 8.59%. Besides, photocatalysis is also a new promising technology to generate renewable energy. We herein develop new low-cost and noble-metal-free photocatalysts based on Co(OH)2 modified CdS nanowires and applied them for visible light driven hydrogen production from water-splitting. The optimum H2 production rate reaches 14.43 mmol·h−1·g−1 under (λ ≥ 420 nm) upon visible light irradiation, which is 206 and 3 times larger than that of the pristine CdS NWs and 1 wt% Pt-CdS NWs, respectively. The results indicate the promising application of earth-abundant Co(OH)2 as alternative cocatalysts of noble metals.

Photodegradation of 4-nitrophenol (4-Np) in the presence of water-soluble zinc phthalocyanines and water-insoluble metallophthalocyanines is reported. The water-soluble phthalocyanines employed include zinc tetrasulphophthalocyanine (ZnPcS[subscript 4]), zinc octacarboxyphthalocyanine (ZnPc(COOH)[subscript 8]) and a sulphonated ZnPc containing a mixture of differently sulphonated derivatives (ZnPcS[subscript mix]), while the water-insoluble phthalocyanines used include unsubstituted magnesium (MgPc), zinc (ZnPc) and chloroaluminium (ClAlPc) phthalocyanine complexes and the ring-substituted zinc tetranitro (ZnPc(NO[subscript 2])[subscript 4]), zinc tetraamino (ZnPc(NH[subscript 2])[subscript 4]), zinc hexadecafluoro (ZnPcF[subscript 16]) and zinc hexadecachloro (ZnPcCl[subscript 16]) phthalocyanines. The most effective water-soluble photocatalyst is ZnPcS[subscript mix] in terms of the high quantum yield obtained for 4-Np degradation (Φ[subscript 4-Np]) as well as its photostability. While ZnPc(COOH)[subscript 8] has the highest Φ[subscript 4-Np] value relative to the other water-soluble complexes, it degrades readily during photocatalysis. The Φ[subscript 4-Np] values were closely related to the singlet oxygen quantum yields Φ[subscript Δ] and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 x 10[superscript 6] mol[superscript -1] dm[superscript 3] s[superscript -1] for ZnPcS[subscript mix] and 7.7 x 10[superscript 6] mol[superscript -1] dm[superscript 3] s[superscript -1] for ZnPc(COOH)[subscript 8]. ClAlPc is the most effective photocatalyst relative to the other heterogeneous photocatalysts for the phototransformation of 4-Np, with 89 ± 8.4 % degradation of 4-Np achieved after 100 min. The least effective catalysts were ZnPcCl[subscript 16] and MgPc. The final products of the photocatalysis of 4-Np in the presence of the homogeneous photocatalysts include 4-nitrocatechol and hydroquinone, while degradation of 4-Np in the presence of the heterogeneous photocatalysts resulted in fumaric acid and 4-nitrocatechol. ClAlPc was employed for the heterogeneous photocatalysis of the non-systemic insecticide, methyl paraoxon. Complete degradation of the pesticide was confirmed by the disappearance of the HPLC trace for methyl paraoxon after 100 min of irradiation with visible light. The removal of 4-Np from an aqueous medium using commercially available Amberlite[superscript ®] IRA-900 modified with metal phthalocyanines was also investigated. The metallophthalocyanines immobilised onto the surface of Amberlite[superscript ®] IRA-900 include Fe (FePcS[subscript 4]), Co (CoPcS[subscript 4]) and Ni (NiPcS[subscript 4]) tetrasulphophthalocyanines, and differently sulphonated phthalocyanine mixtures of Fe (FePcS[subscript mix]), Co (CoPcS[subscript mix]) and Ni (NiPcS[subscript mix]). Adsorption rates were fastest for the modified adsorbents at pH 9. Using the Langmuir-Hinshelwood kinetic model, the complexes showed the following order of 4-Np adsorption: CoPcS[subscript mix] > NiPcS[subscript 4] > NiPcS[subscript mix] > FePcS[subscript 4] > FePcS[subscript mix] > CoPcS[subscript 4]. The adsorbents were regenerated using dilute HNO[subscript 3], with 76 % (7.6 x 10[superscript -5] mol) of 4-Np recovered within 150 min.

Photochemical properties of sulphonated phthalocyanine complexes of aluminium, zinc, tin and silicon, and octa-carboxyphthalocyanine complexes of aluminium and zinc have been investigated. These water-soluble metallophthalocyanine (MPc) complexes, especially the sulphonated aluminium and zinc phthalocyanines, were found to be good photosensitisers for the transformation of the toxic mono-, tri- and penta-chlorophenols in aqueous solutions. The efficiency of MPc sensitiser towards photo-transformation of chlorophenols depends on its effectiveness to generate singlet oxygen as well as its photostability. Octa-substituted thiol-derivatised phthalocyanine complexes of cobalt, iron and zinc were synthesized and their spectral and electrochemical properties investigated. The photochemical properties ofthe zinc phthalocyanine complexes in non-aqueous solutions were comparable to those in literature. Ultrathin films of the octasubstituted thiol-derivatised phthalocyanine complexes of cobalt, iron and zinc were, for the first time, immobilized onto gold electrodes using the self-assembling technique. Surface electrochemistry indicates that the ultrathin films are surface-confined self-assembled monolayer (SAM) species. Gold electrodes modified with the redox-active SAMs of cobalt and iron phthalocyanine complexes proved to be potential electrochemical sensors for the detection of thiols (L-cysteine, homocysteine and penicillamine) and thiocyanate in aqueous solutions (pH 4). The limits of detection for the thiols and thiocyanate were in the range of ∼ 10⁻⁷ and 10⁻⁶ mol dm⁻³, respectively. The modification process was reproducible and the modified electrodes showed good stability and, if stored in pH 4 buffer solutions, could be used for the analysis of thiols and thiocyanate for about a month without the need for recalibration. Etching of gold marred electrochemical detection of cyanide with the MPc-SAM-modified gold electrodes. Interestingly, however, kinetic and equilibria studies revealed strong interaction of octabutylthiophthalocyaninatoiron (II), FeOBTPc, with cyanide in both DMF and DMSO solutions.