Novel conductive multi-walled polymeric nanotubes of poly(diazoaminobenzene) for single-layer polymer solar cell

https://doi.org/10.1016/j.reactfunctpolym.2020.104529Get rights and content

Highlights

  • Synthesis of a novel multi-walled polymeric nanotube (MWPNT) of poly(diazoaminobenzene) (PDAAB) was described.

  • Synthesis involved a one-pot, acid and template-free green method at room temperature.

  • PDAAB was observed to have azo groups appended along its entire backbone.

  • The fabrication of single-layer polymer solar cells using PDAAB was reported.

  • Solar cells were compared using PDAAB before and after wash with ethanol.

Abstract

Novel conductive and flexible multi-walled polymeric nanotubes (MWPNTs) of poly(diazoaminobenzene) (PDAAB) were synthesized using diazoaminobenzene monomer for the first time in this report. The synthesis followed a one-pot, cost-effective, green and template-free procedure, in which aniline was used as initiator with 87% yield at room temperature. PDAAB was characterized with spectroscopic and microscopic methods such as Fourier-transform infrared (FTIR), UV–vis, X-ray diffractometry (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM) as well as cyclic voltammetry (CV) and conductivity measurements. In addition, MWPNTs were used in the design of a novel single-layer polymer solar cell. PDAAB was sandwiched between TiO2 nanoparticle-modified fluorine-doped tin oxide (FTO) electrode and an aluminum electrode (FTO-TiO2│PDAAB│Al), as anode and cathode, respectively. Finally, various physical characteristics of the single-layer polymer solar cell were determined under simulated solar irradiation. Our proof-of-concept study demonstrated that MWPNTs provided a promising platform to develop polymer-based solar energy conversion and storage systems.

Introduction

The photoisomerization of the azo chromophores has been a topic that has caught the attention of researchers in a wide variety of research fields [[1], [2], [3], [4], [5], [6], [7], [8]]. There has been a demand to understand the role of chromophores on changing the properties of these polymeric materials. It is known that the azobenzene segment employs as a trigger for the introduction of the morphological changes. Based on these studies, it is now known that the presence of an azo chromophore can modulate both electroactivity and photoactivity of polymers. The application of different conducting polymers such as polypyrrole, polythiophene, polyphenylene and polyaniline (PANI) have been reported for devepoling of green and renewable energy with solar cells due to the presence of a conjugated π-electron backbone [[9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21]]. The synthesis of conjugated polymers such as azo-linked materials has been reported with various synthetic routes in the literature [7] but their applications in solar cells have been limited. Synthesis of azo-linked polymers with solubilizing alkyl side chains based on thiophene and fluorene as well as using palladium and copper-catalyzed polymerizations have been reported previously [[22], [23], [24], [25]]. These conductive polymers make up a novel class of organic electronic materials that can be utilized for various applications such as drug delivery [26], transistors, sensors, optical storage [27], LED and solar cells [28]. Based on these discoveries, the morphology of polymers has become one of the important factors for increasing the power conversion efficiency (PCE or %η) of polymer solar cells [29]. Yang et al. [30] have reported the effect of morphology of poly(3-hexylthiophene) and methanofullerene derivatives in solar cells. Based on this study, the high performance of polymers were dependent on the crystal structure and mixing them at varying temperatures to prepare a smooth layer. The same result was reported by Shao et al. [31] and van Duren et al. [32]. Chang et al. [33] have also reported 26% increase in PCE photovoltaic performance for an acid-doped PANI nanotube layer. These reports described that the photovoltaic performance of PANI improved with the annealing of polymer layer due to the increase in conductivity and mobility as well as the controlled tubular nanoscale morphologies. Dye-sensitized solar cells (DSSCs) using PANI–ZnS and PANI-CdS nanotubes have been reported [34,35]. Park et al. [36] have reported DSSCs by using porous PANI nanotubes as a counter electrode. The effect of different factors in the fabrication of nanostructures of the conjugated polymers in organic solar cells was reported by Chen and Hsu [37]. Also, the morphological effect of TiO2 nanoparticles and PANI nanofibers on the photovoltaic activity as a new nano-composite of (PANI nanofibers)/(TiO2 nanoparticles) with different architectures have been recently reported by our research group [38]. In the organic and hybrid (organic-inorganic) solar cells, both multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNT) were used for increasing electron tranfer rate. SWCNTs and MWCNTs have different functions due to differences in their band gap [39,40]. The dispersion and orientation of the CNTs in the organic matrix and their effect on the efficiency of solar cells were discussed by Aernouts et al. [41].

DSSCs including azo group compounds have been reported [[42], [43], [44], [45], [46], [47]], but there is no report about their application in the single-layer polymer solar cells, to the best of our knowledge. Meena et al. [48] have recently reported the application of the azo linkage in a multi-layer cell as a main chain with PCE of 0.53%.

Diazoaminobenzene (DAAB) or 1,3-diphenyltriazene is an aromatic amine which has been used for the preparation of several important complexes due to its high concentration of nitrogen atoms [[49], [50], [51], [52]]. Because of its nitrogen double bond (N=N), the photochemistry and cis-trans isomerization of DAAB has been examined [[53], [54], [55]]. In our previous reports, PANI with a nanostructure and poly(p-aminoazobenzene) nanosheets were assembled in the structure of polymer single-layer solar cells [56,57]. To the best our knowledge, there is no report for polymerization of DAAB. In this study, for the first time, a novel conductive poly(diazoaminobenzene) (PDAAB) with multi-walled polymeric nanotube (MWPNT) morphology was synthesized and characterized. The synthesis method developed for MWPNTs of PDAAB is a template-free and green one. In addition, MWPNTs were utilized in the development of single-layer polymer solar cells and their photovoltaic properties were investigated in detail and compared with others reported in literature.

Section snippets

Materials and equipment

Reagents of analytical grade were used without any purification except for aniline, which was purified by distillation. Diazoaminobenzene monomer was purchased from Sigma-Aldrich (Oakville, ON) and also, it was synthesized following the literature method [58]. A JASCO Fourier transform infrared spectrophotometer (Easton, MD) and a Shimadzu UV–visible spectrophotometer (Kyoto, Japan) were used for recording the spectra. An ECS 4010 Nitrogen/Protein Analyzer (Costech Analytical Technologies,

FT-IR analysis

Fig. 2 displays the FT-IR spectra of PDAAB and DAAB. The broad peaks for PDAAB exhibited to the vibrational modes in polyaniline. Similar observations were reported in literature [38,[62], [63], [64], [65]]. The Nsingle bondH bonds indicated stretching absorption at 3000–3200 cm−1 and the Raman active single bondCdouble bondCsingle bond ring stretching vibration at 1603 cm−1.

It is known when the protonation induced the conformational changes in the polymer chain, the infrared-inactive modes became infrared-active, which indicated that

Conclusions

In this study, for the first time, the polymerization of the monomer diazoaminobenzene is reported to produce a novel PDAAB via a very simple, one-pot, green, acid and template-free method at room temperature. The synthetic method involves pH-falling and rapid-mixing in the presence of aniline as an initiator at room temperature. The aniline has a critical role in the onset of the reaction and the polymer cannot be formed in the absence of it. Based on these results, PDAAB was observed to have

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Declaration of Competing Interest

The authors declare no conflict of interest.

Acknowledgments

The authors acknowledge the financial support of a grant from the Graduate Council of University of Sistan and Baluchestan and the National Nanotechnology Initiative of Iran. K. K. gratefully acknowledges Canada Research Chair Tier-2 award in "Bioelectrochemistry of proteins" (project no. 950-231116), the Ontario Ministry of Research and Innovation (Project no. 35272), Discovery Grant (project no. 3655) from the Natural Sciences and Engineering Research Council of Canada (NSERC), and the Canada

References (103)

  • J.A. Mikroyannidis et al.

    Efficient bulk heterojunction solar cells based on low band gap bisazo dyes containing anthracene and/or pyrrole units

    Sol. Energy Mater. Sol. Cells

    (2010)
  • T. Jack et al.

    Conformational studies of π-allylic palladium complexes of 1, 3-diphenyltriazene and 1-methyl-3-phenyltriazene

    J. Organomet. Chem.

    (1971)
  • D. Pfeiffer et al.

    Synthesis, structure, and characterization of lanthanide complexes bearing 1,3-diphenyltriazenido ligands

    J. Organomet. Chem.

    (1999)
  • P. Zhao et al.

    1,3-diphenyltriazene as a possible optical molecular switch: a first-principles study

    Phys. B Condens. Matter

    (2009)
  • S. Shabzendedar et al.

    Synthesis and characterization of poly(p-aminoazobenzene) nanosheet as a new derivative of polyaniline containing azo groups under green chemistry condition and its high efficiency in solar cell

    Synth. Met.

    (2019)
  • C.J. Brabec et al.

    The influence of materials work function on the open circuit voltage of plastic solar cells

    Thin Solid Films

    (2002)
  • A. Volkov et al.

    Electrochemical polymerization of aromatic amines: IR, XPS and PMT study of thin film formation on a Pt electrode

    J. Electroanal. Chem. Interfacial Electrochem.

    (1980)
  • T. Ohsaka et al.

    IR absorption spectroscopic identification of electroactive and electroactive polyaniline films prepared by the electrochemical polymerization of aniline

    J. Electroanal. Chem. Interfacial Electrochem.

    (1984)
  • A. Farrokhzadeh et al.

    Complete doping in solid-state by silica-supported perchloric acid as dopant solid acid: synthesis and characterization of the novel chiral composite of poly [(±)-2-(sec-butyl) aniline]

    J. Solid State Chem.

    (2016)
  • J. Stejskal et al.

    Polyaniline nanostructures and the role of aniline oligomers in their formation

    Prog. Polym. Sci.

    (2010)
  • R. Patil et al.

    Mobilities of charge carriers in poly (o-methylaniline) and poly (o-methoxyaniline)

    Electrochim. Acta

    (2004)
  • J. Stejskal et al.

    The genesis of polyaniline nanotubes

    Polym.

    (2006)
  • M. Trchová et al.

    FTIR spectroscopic and conductivity study of the thermal degradation of polyaniline films

    Polym. Degrad. Stab.

    (2004)
  • A.G. MacDiarmid et al.

    The concept of secondary doping as applied to polyaniline

    Synth. Met.

    (1994)
  • T.C. Huang et al.

    Electrochemical investigations of the anticorrosive and electrochromic properties of electroactive polyamide

    Electrochim. Acta

    (2012)
  • S. Zhou et al.

    Effect of methanol on morphology of polyaniline

    Eur. Polym. J.

    (2007)
  • M. Bláha et al.

    Effects of the polymerization temperature on the structure, morphology and conductivity of polyaniline prepared with ammonium peroxodisulfate

    Eur. Polym. J.

    (2013)
  • C. Laslau et al.

    Theories of polyaniline nanostructure self-assembly: towards an expanded, comprehensive Multi-Layer Theory (MLT)

    Prog. Polym. Sci.

    (2010)
  • C. Appiah et al.

    Crystallization behavior of precision polymers containing azobenzene defects

    Eur. Polym. J.

    (2017)
  • Z. Han et al.

    Synthesis and application in solar cell of poly(3-octylthiophene)/titania nanotubes composite

    Org. Electron.

    (2010)
  • M.S. Katore et al.

    Photovoltaic study of chemically engineered nano-titanium oxide loaded polyaniline matrix of architecture ITO/titanium oxide-polyaniline/aluminum

    Synth. Met.

    (2015)
  • Z. Liu et al.

    Polyaniline/TiO2 solar cells

    Synth. Met.

    (2006)
  • E. Merino et al.

    Control over molecular motion using the cis-trans photoisomerization of the azo group

    Beilstein J. Org. Chem.

    (2012)
  • Y. Gao et al.

    Stimuli-responsive polymers: fundamental considerations and applications

    Macromol. Res.

    (2017)
  • O.S. Bushuyev et al.

    Shape-shifting azo dye polymers: towards sunlight-driven molecular devices

    Macromol. Rapid Commun.

    (2018)
  • J. Wei et al.

    Photodeformable polymer gels and crosslinked liquid-crystalline polymers

    Soft Matter

    (2012)
  • S. Xie et al.

    Recent developments in aromatic azo polymers research

    Chem. Mater.

    (1993)
  • A. Ravve

    Photoresponsive polymers

  • G.S. Kumar et al.

    Photochemistry of azobenzene-containing polymers

    Chem. Rev.

    (1989)
  • Y. Kwon et al.

    Conducting polymer coating on a high-voltage cathode based on soft chemistry approach toward improving battery performance

    ACS Appl. Mater. Interfaces

    (2018)
  • W. Wei et al.

    A review on PEDOT-based counter electrodes for dye-sensitized solar cells

    Int. J. Energy Res.

    (2014)
  • M. Ates et al.

    Conducting polymers and their applications

    Curr. Phys. Chem.

    (2012)
  • T.K. Das et al.

    Review on conducting polymers and their applications

    Polym.-Plast. Technol. Eng.

    (2012)
  • E.M. Johansson et al.

    Combining a small hole-conductor molecule for efficient dye regeneration and a hole-conducting polymer in a solid-state dye-sensitized solar cell

    J. Phys. Chem. C

    (2012)
  • J.W. Jung et al.

    High-efficiency polymer solar cells with water-soluble and self-doped conducting polyaniline graft copolymer as hole transport layer

    J. Phys. Chem. C

    (2009)
  • Y. Otsuka et al.

    Photoinduced formation of polythiophene/TiO2 nanohybrid heterojunction films for solar cell applications

    J. Phys. Chem. C

    (2008)
  • Z. Yin et al.

    Controlled synthesis and energy applications of one-dimensional conducting polymer nanostructures: an overview

    Adv. Energy Mater.

    (2012)
  • J.F. Mike et al.

    Recent advances in conjugated polymer energy storage

    J. Polym. Sci. B Polym. Phys.

    (2013)
  • S. Peng et al.

    Polypyrrole nanorod networks/carbon nanoparticles composite counter electrodes for high-efficiency dye-sensitized solar cells

    ACS Appl. Mater. Interfaces

    (2011)
  • G. Kaur et al.

    Electrically conductive polymers and composites for biomedical applications

    RSC Adv.

    (2015)
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