Recent advances in phthalocyanines for chemical sensor, non-linear optics (NLO) and energy storage applications

Phthalocyanines (Pcs) are intensely coloured, robust macrocycles that possess admirable chemical, thermal and photo- stability as a result of its extensive π-network. The Pc family has established their fundamental and technological importance in numerous applications due to structural versatility and unique properties that result from the incorporation of a variety of inorganic and organic components into its framework. The diversity of Pc structures allows for the optimisation of certain properties to obtain functional, high-performance materials. The combination of aromaticity, relatively simple synthesis and structural flexibility makes Pcs a great asset for numerous scientific and industrial advancements. This review focuses on recent advances (2014–2020) of phthalocyanines in the specific technologies of chemical sensors, non-linear optics (NLO), and energy storage applications. Many MPc complexes reported to date favour select metals and ligand derivatives which leaves huge opportunities for further exploration.The National Research Foundation, South Africa and the University of KwaZulu-Natal (UKZN), South Africa.http://www.elsevier.com/locate/ccr2022-06-23hj2021Chemistr

Synthesis, spectroscopic and DFT characterization of 4 β -(4-tert-butylphenoxy) phthalocyanine positional isomers for non-linear optical absorption

In this work the synthesis, spectral characterization and non-linear optical properties of metal-free 4β-(4-tert-butylphenoxy) phthalocyanine isomers are described and compared to the previously reported alpha derivative. The second-order nonlinear optical properties of the phthalocyanine isomers were investigated using the Z-scan technique and compared to the theoretical data obtained from density functional theory (DFT) and time dependent density functional theory (TD-DFT) calculations. Z-scan results indicated strong non-linear behaviour, revealing reverse saturable absorption (RSA) profiles for all four isomers. The experimental βexp values showed the following trend:C4h (9.31×10–10mMW–1)>D2h (7.89×10–10mMW–1)>Cs (7.32× 10–10 mMW–1) > C2v (1.77 × 10–10 mMW–1). These results were similar to that obtained with the 4β-(4-tert-butylphenoxy) phthalocyanines as the C2v and Cs isomers were found to have the lowest βexp values compared to other symmetries. The 4β-(4-tert-butylphenoxy) phthalocyanine C4h isomer was found toshowbetter non-linear optical properties compared to all other isomers.Keywords: Phthalocyanine, non-linear optical absorption, density functional theory, magnetic circular dichrois

Fabrication and processing of bacterial cellulose/silvernanowire composites as transparent, conductive, andflexible films for optoelectronic applications

DATA AVAILABILITY : The data that support the findings of this study are avail-able in the supplementary material of this article.SUPPORTING INFORMATION : DATA S1 : Supplementary Information.This work reports on the engineering and fabrication of transparent, conductive, and flexible films made as a composite of bacterial cellulose microfibers (BMF), a polymer (either PVA or PEO), and silver nanowires (AgNWs) as viable and cost-effective replacements to commercial indium-tin oxide (ITO) and fluorine-doped tin oxide (FTO) transparent conductors. The studies conducted indicate that the optical and mechanical properties of BMF-polymer substrates are tuneable by varying the ratio of BMF to polymer. An optimized ratio of 70:30 of BMF to polymer was established for BMF-PVA and BMF-PEO composites. The optimized composite films were coated with varying amounts of AgNWs. As the AgNW loading increased, the deposition density of AgNW networks increased, while the sheet resistance and optical transmittance decreased. The optimum AgNW loading was determined at 0.20 mg for both composite films. The BMF-PVA-AgNW film displayed transmittance between 81% and 71% and an average resistivity of 9.462 ± 0.588 Ω/sq while the BMF-PEO-AgNW films showed transmittance between 73% and 65% and an average resistivity of 9.388 ± 0.1.375 Ω/sq. These properties compared well to that of commercial ITO and FTO glass substrates. The findings promote cellulose-based composites as low-cost, lightweight, and durable substrates for optoelectronic applications.The National Research Foundation South Africa and the University of KwaZulu-Natal (UKZN).http://wileyonlinelibrary.com/journal/appChemistr

Electroanalytical detection of heavy metals using metallophthalocyanine and silica-coated iron oxide composites

Please read abstract in the article.The National Research Foundation of South Africa for the Thuthuka research Grant.https://link.springer.com/journal/116962019-12-01hj2018Chemistr

Metallophthalocyanines in a ternary photoactive layer (P3HT:MPc:PC70BM) for bulk heterojunction solar cells

Novel bulk heterojunction (BHJ) organic photovoltaic (OPV) solar cells have been fabricated by introducing a series of metallophthalocyanines (MPcs) into a blend of a poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl C70 butyric acid methyl ester (PC70BM) photoactive layer. Sixteen MPcs have been synthesised with due consideration of the metal type and valency, functionalised ligand moieties and their respective molecular energy levels. The MPcs were expected to act as an electron cascade material that improves photovoltaic performance in a two-fold manner. Firstly, to provide an efficient energy level offset between the polymeric donor (P3HT) and the fullerene-based derivative acceptor (PC70BM) to enhance charge transfer and reduce recombination within the OPV solar cells. Secondly, to harvest a greater portion of the solar spectrum as MPcs are associated with absorption near the near-infrared region. The BHJ OSCs were fabricated in the following inverted configuration: ITO/TiO2/P3HT:MPc:PC70BM/WO3/Ag and were investigated for their optimum photovoltaic performance. The BHJ OSCs comprising of P3HT, PC70BM and the manganese MPc (MnPc) series photoactive layer displayed the best PCEs ranging between 2.36 – 2.62% which were approximately 47.5 - 63.7% higher than the binary reference BHJ OSCs.publishe

Electroanalytical detection of heavy metals using metallophthalocyanine and silica-coated iron oxide composites

Please read abstract in the article.The National Research Foundation of South Africa for the Thuthuka research Grant.https://link.springer.com/journal/116962019-12-01hj2018Chemistr