Affordable dye sensitizer by waste

Abstract The development of dye sensitizer is growing in line with the increasing demand for renewable energy. A research to obtain a dye sensitizer that is economical, safe, and produces a great value of DSSC efficiency is a challenge unresolved. On the other hand, the efforts for waste reduction are also intensively conducted to create better environment. In this paper, the variation of synthetic dye wastes from batik industries have been successfully applied as dye sensitizer and fabricated on DSSC cells. Congo red (1.0133%) yielded higher efficiency than rhodamine B (0.0126%), methyl orange (0.7560%), and naphthol blue black (0.0083%). The divergence of the efficiency of DSSC is very dependent upon the chromophore group owned by dye. This study has proven that the more chromophore group possessed by dye, the higher the efficiency of DSSC generated. This research concludes that the dye wastes have a bright future to be implemented as dye sensitizer on solar cells

Carbon nanotube-enhanced photoelectrochemical properties of metallo-octacarboxyphthalocyanines

The photoelectrochemistry of metallo-octacarboxyphthalocyanines (MOCPc, where M = Zn or Si(OH)2) integrated with MWCNTs for the development of dye-sensitized solar cells (DSSCs) is reported. The DSSC performance (obtained from the photo-chronoamperometric and photo-impedimetric data) decreased as ZnOCPc > (OH)2SiOCPc. The incorporation of the MWCNTs on the surface of the TiO2 film (MOCPc–MWCNT systems) gave higher photocurrent density than the bare MOCPc complexes. Also, from the EIS results, the MOCPc–MWCNT hybrids gave faster charge transport kinetics (approximately three times faster) compared to the bare MOCPc complexes. The electron lifetime was slightly longer (ca. 6 ms) at the ZnOCPc systems than at the (OH)2SiOCPc system (ca. 4 ms) meaning that the presence of the MWCNTs on the surface of the TiO2 film did not show any significant improvement on preventing charge recombination process

Combinatorial effects of genistein and sex-steroids on the level of cystic fibrosis transmembrane regulator (CFTR), adenylate cyclase (AC) and cAMP in the cervix of ovariectomised rats

The combinatorial effects of genistein and estrogen (E) or estrogen plus progesterone (E + P) on CFTR, AC and cAMP levels in cervix were investigated. Ovariectomised adult female rats received 50 or 100 mg/kg/day genistein with E or E followed by E + P [E + (E + P)] for seven consecutive days. Cervixes were harvested and analyzed for CFTR mRNA levels by Real-time PCR. Distribution of AC and CFTR proteins in endocervix were observed by immunohistochemistry. Levels of cAMP were measured by enzyme-immunoassay. Molecular docking predicted interaction between genistein and AC. Our results indicate that levels of CFTR, AC and CAMP in cervix of rats receiving genistein plus E were higher than E-only treatment (p < 0.05) while genistein plus [E + (E + P)] were higher than E + (E + P)-only treatment (p < 0.05). In conclusions, increased levels of CFTR, AC and cAMP in cervix of E and E + (E + P)-treated rats by genistein could affect the cervical secretory function which could influence the female reproductive processes. (C) 2015 Elsevier Inc. All rights reserved

Intramolecular electron transfer in porphyrin-anthraquinone donor-acceptor systems with varying molecular bridges

Photoinduced electron transfer has been investigated in porphyrin anthraquinone (ZnTTP-AQ) donor-acceptor dyads having either ester (ZnTTP-AQ1) or ether (ZnTTP-AQ2) linkages. Both dyads were characterized by spectroscopic and electrochemical methods. Absorption spectra show absence of any ground state interaction between the porphyrin and anthraquinone moieties. The quenched fluoresence and lifetime indicate electron transfer from the porphyrin to the anthraquinone moiety. The quenching is more pronounced in ZnTTP-AQ1 with ester linkage, suggesting efficient electronic coupling compared to the ether linkage in ZnTTP-AQ2. Computational analysis and frontier molecular orbitals confirmed the formation of charged separated state por+AQ-. The electron transfer rates (kET) of these triads are found in the range 0.43 × 10 8 to 10.52 × 10 9 s-1 and are found to be solvent polarity dependent

Solution processed aligned ZnO nanowires as anti-reflection and electron transport layer in organic dye-sensitized solar cells

Aligned one-dimensional nanostructure-based solar cells have lower-performance than traditional dye-sensitized solar cells (DSSC); due to optical and electrical losses. In this letter, we minimized optical/electrical-loss by using low-temperature solution-processed ZnO nanowires (NW) as anti-reflection(AR)/electron-transport(ET) layer in newly designed indoline dye based-DSSCs. AR-layered organic-DSSC exhibit better durability performance and enhanced photocurrent density (Jsc), &gt;26% compared to the bare devices; due to the enhanced light-coupling. Additionally, this letter debates the techniques to increase performance of the DSSCs in terms of current and voltage in detail. Such AR/ET layered architecture will be of broad academic and industrial interest, for example in photodetectors and so on

Unsymmetrical phenanthro-imidazole/phenothiazine conjugates for optoelectronic applications

We designed and synthesized two small unsymmetrical phenanthro-imidazole/phenothiazine molecules with (OHM-2) and without (OHM-1) a phenyl-π-spacer. The optical and electrochemical properties were measured to determine the band-gap and HOMO energy values of these molecules. It was observed that the phenyl-π-spacer played a crucial-role in lowering the hole-reorganization energy, extending the conjugation for improved electrical properties, and tuning the optical/electrochemical properties for optoelectronic applications. An alkyl-chain introduced on structure increased the hydrophobicity, improving stability in ambient atmosphere applications. Unsymmetrical phenanthro-imidazole/phenothiazine molecules were shown to be a suitable, versatile hole-transporting material for highperformance optoelectronic devices

Photoinduced energy transfer in carbazole-BODIPY dyads

A series of carbazole (CBZ)boron dipyrromethene (BODIPY) based donoracceptor dyads, CB1, CB2, and CB3, with CBZ as an energy donor, tethered together with spacers of varied sizes i.e., phenyl bridge, biphenyl bridge and diphenylethyne bridge, respectively, are reported. The newly synthesized dyads were characterized by various spectroscopic techniques. A comparison of the absorption and electrochemical data of the dyads with their reference compounds (i.e., 9-phenyl-9H-carbazole (C0) and N,N0-difluoroboryl-1,3,7,9-tetramethyl-5-phenyldipyrrin (B0)) revealed minimal ground-state interactions between the chromophores. Selective excitation of CBZ in the dyads at 290 nm resulted in the quenching of the CBZ emission followed by the appearance of BODIPY emission, revealing efficient energy transfer from singlet excited CBZ (1CBZ*) to BODIPY. The photoinduced energy transfer phenomenon was studied in three different solvents of varying polarity. The driving forces for energy transfer (DGEN) for all the dyads were found to be exothermic. The rate constants for energy transfer, kENT, measured by the femtosecond transient absorption technique in toluene were found to be in the range of 0.82.0 1010 s1, depending on the type of spacer between the CBZ and BODIPY entities, and were in close agreement with the theoretically estimated rates according to the Fo¨rster energy transfer model. In contrast, selective excitation of BODIPY in these dyads at 485 nm resulted in small quenching of the BODIPY emission, suggesting a lack of major photochemical events originating from 1BODIPY*