Encapsulation of poly(m-aminobenzodioxol)-Fe3O4 superparamagnetic nanorods and iron (III) thiocyanate complex in hydrogel toward hybrid solar cells

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Abstract

In this proof-of-concept study, a nanocomposite of poly(m-aminobenzodioxol) with Fe3O4 magnetic nanorods (PABD-Fe3O4NRs) was synthesized using a one-pot synthesis. The nanocomposite was characterized using transmission electron microscopy (TEM), environmental scanning electron microscopy (ESEM), and Fourier-transform infrared spectroscopy (FT-IR), which all displayed successful synthesis. The PABD-Fe3O4NRs were then incorporated within a graphite-implanted polyacrylamide (PAA-G) hydrogel matrix to develop an innovative nanocomposite-polymer solar cell. The additional Fe3+ was then used to form a metal thiocyanate complex, [FeSCN]2+, within the pores of the hydrogel. To the best of our knowledge, this study is the first to report the use of a conductive hydrogel nanocomposite for the encapsulation of the active layer within a hybrid solar cell. The incorporation of this material as a single layer enabled storage of the [FeSCN]2+ solution as well as increased the formation of interconnected channels for faster electron transfer and diminished charge transfer resistance, and therefore, significantly enhanced the overall efficiency of the solar cell. Under simulated solar irradiation, the final FTO│TiO2 / PAA-G-PABD-Fe3O4NRs gel [FeSCN]2+ │Al solar cell demonstrated a power conversion efficiency (PCE or η) of 6.08% and a significant enhancement of 2100% in comparison with the solar cells fabricated with PABD-Fe3O4NRs in the absence of the PAA-G and [FeSCN]2+ complex. Our preliminary results exhibited high thermal stability and displayed superior photovoltaic properties when compared to other similar solar cells in literature. We envisage that the synthesis of hydrogel nanocomposites using various nanomaterials will significantly enhance the development of high-efficiency hybrid solar cells.

Introduction

Due to growing environmental issues and global warming, the development of novel renewable energy sources has gained significant scientific and industrial attention [1], [2], [3], [4]. For example, there is an urgent need for the development of innovative, efficient and low-cost solar cells to replace the extensive use of fossil fuels. These devices, that harvest solar energy by converting solar radiation into usable electricity, are essential for the future advancement of renewable and sustainable energy. Solar energy is the only sustainable energy source able to provide all the energy humans need. In fact, more energy hits the earth in one hour than the world utilizes in one year [5].

Polymer-based solar-cells are promising green candidates for energy conversion and storage due to their simple synthesis and lower cost [6], [7], [8], [9]. Conductive polymers are often used as the redox-active layer material in the fabrication of solar cells due to the excellent advantages such as high conductivity, high stability, low-cost synthesis and easy manipulation of chemical properties [6], [7], [8], [9], [10], [11], [12]. One of the most commonly applied conducting polymers in solar cells is polyaniline (PANI) and its derivatives. PANI polymers provide multiple oxidation states with various colours and acid/base doping sensitivity at a low-cost [9]. Moreover, due to their unique conduction mechanism and stability, they have been used as a counter electrode, a donor in the active layer, and as an anode buffer layer [6], [7]. However, further research is necessary to improve the overall performance and efficiency of these polymer-based solar cells. More recently, innovative magnetic polymer nanocomposites have been shown to be very promising in enhancing the performance of different types of solar cells. More specifically, Fe3O4 nanoparticles are often used to dope the polymers in the active redox-layer of solar cells [6], [10], [11], [12], [13]. Fe3O4 nanoparticles have been reported to play a significant role in enhancing the photovoltaic efficiency of organic polymer solar cells [10], [11], [12], [13], [14]. More specifically, Fe3O4/PANI composite has been shown to possess exceptional electrical and magnetic characteristics that can be exploited in many applications such as magnetic, electronic and photovoltaic devices. The polymer chains of PANI were reported to coat the Fe3O4 nanoparticles and provide them with high stability [6], [15], [16]. A few studies exist where derivatives of PANI/Fe3O4 composites were synthesized for applications such as biosensors [17], [18], as adsorbents to remove heavy metals and dyes [19], [20] and for fuel cells [21]. For the first time, our group reported that it is possible to use derivatives of PANI/ Fe3O4 composites in solar cells as well [6], [22]. Moreover, a new one-pot solid-state synthesis of a superparamagnetic derivative of PANI/ Fe3O4 nanocomposites was described and published by our group [6], [22]. In this method, FeCl3.6H2O was used and had a dual role in the reaction; it acted as an oxidant for polymerization of the PANI derivate and as the precursor for the synthesis of Fe3O4 nanoparticles since it had Fe2+ as a source. This method was beneficial because it allowed for simultaneous synthesis of the polymer and the Fe3O4 nanoparticles, reducing the number of steps in the process [6], [22]. Using a similar technique, we synthesized this nanocomposite, poly(m-aminobenzodioxol) with superparamagnetic Fe3O4 nanorods (PABD- Fe3O4NRs), using 5-amino-1,3-benzodioxole as a monomer in this proof-of-concept report [22]. Superparamagnetic derivatives of PANI/ Fe3O4 nanocomposites have been proven to have an enhanced effect on the efficiency of solar cells [6], [23].

Hydrogels are cross-linked polymers that have the ability to retain large amounts of aqueous solutions mainly through hydrogen bonding [24], [25]. These materials have an exclusive three-dimensional (3D) porous network that also enables them to encapsulate different types of nanomaterials to form versatile nanocomposites [26], [27], [28]. Hydrogels have previously been used for various applications such as tissue engineering, wound dressing, drug delivery, removal of heavy metals and dyes, coal dewatering, biosensors, consumer products, and solar cells [29], [30], [31], [32], [33], [34], [35], [36], [37].

One of the most studied hydrogels is made from cross-linked polyacrylamide (PAA). PAA is an ideal hydrogel to use in solar cell applications because it is very versatile and easy to synthesize. It also has a very high swelling capacity which allows us to incorporate various nanomaterials and aqueous solutions within its pores. Moreover, PAA has strong mechanical properties, flexibility, elasticity, and stretchability [29], [38], [39]. It is also able to maintain its stability in different harsh conditions [25], [38], [39], [40], [41]. Often the hydrogel is used to store the electrolyte solution (gel electrolyte) because it provides a great combination of both the stability of a solid-state electrolyte and high charge transfer ability of a typical liquid electrolyte [34], [42]. So far, PAA-based hydrogel electrolytes have mainly been incorporated in dye-sensitized solar cells (DSSCs) [24], [42], [43] and quantum dot-sensitized solar cells (QDSCs) [34], [44], [45], [46], [47]. To create these gels, the liquid electrolyte is loaded into the matrix of the gel mainly by osmotic pressure which is the driving force of the process. More specifically, the mechanism of the absorption of electrolyte is governed by the Flory theory [34], [42]. When the gel electrolyte is sandwiched between the photoanode and a counter electrode, the reduction reaction occurs at the electrolyte/counter electrode interface [34], [42]. In order to accelerate the reduction of redox species in the solar cell system, conducting polymers (e.g. PANI, polypyrole) [43] and carbonaceous materials (e.g. graphite and graphene oxide) [42], [48], [49] have previously been incorporated into the gel matrix. This allowed the electrocatalytic reaction to expand from electrolyte/counter electrode interface to both interface and the gel electrolyte. Moreover, it has been reported that the incorporation of these carbonaceous materials significantly enhanced the performance of the solar cells by shortening the charge diffusion path length, increasing the loading of the electrolyte within the network of the gel and increasing the formation of 3D interconnected conducting channels for enhanced electron transfer [34], [42]. For the first time, instead of electrolyte solution, in this study we incorporate [FeSCN]2+ complex in the matrix of the hydrogel. [FeSCN]2+ is a complex formed when we combined the excess Fe3+ from the synthesis of the PABD- Fe3O4NRs composite with thiocyanate (SCN-). The SCN- reacted with Fe3+to give [FeSCN]2+ complex which developed a very intense red colour [50]. We hypothesized that incorporating this complex within the matrix of our hydrogel would further enhance the performance because the complex could potentially act as a photo-absorber in the ideal range. The combination of the PABD-Fe3O4NRs composite and the [FeSCN]2+ complex within the PAA hydrogel matrix enabled us to create this ideal active material for a hybrid solar cell. Furthermore, having a hydrogel matrix improved the stability of the solar cell because it not only protected the polymer from any heat/ light degradation, but it also slowed down the evaporation process of the aqueous [FeSCN]2+ complex. Due to the porous- nature of the hydrogel, we could easily encapsulate various materials (magnetized polymer, graphite and [FeSCN]2+ complex). The encapsulation of the [FeSCN]2+ complex within the pores of hydrogel matrix allowed for a more homogenous distribution in the polymer layer.

In this proof-of-concept study, to further enhance these effects, we have encapsulated a magnetic nanocomposite of PABD-Fe3O4NRs in a graphite-modified PAA hydrogel (PAA-G) as a single layer. We hypothesized that including the PABD-Fe3O4NRs within the PAA-G hydrogel with [FeSCN]2+ and sandwiching them between the photoanode and a counter electrode would increase the formation of interconnected channels which increased the electrocatalytic area and suppressed the charge-transfer resistance [34] and in turn lead to a significant enhancement in the efficiency of the hybrid solar cell. To the best of our knowledge, there has been no report where PABD-Fe3O4NRs were incorporated within a PAA-G hydrogel matrix along with [FeSCN]2+ complex and employed in the development of a high-efficiency solar cell. Moreover, the encapsulation of an entire active layer within a hydrogel matrix to be used as a single layer in a solar cell was achieved for the first time in this report.

Section snippets

Materials

Acrylamide (99% purity), N,N′-methylenebis(acrylamide) (99.5% purity), potassium persulfate, graphite powder, potassium iodide (KI, 99.5% purity), iodine (I2, 99.8% purity), sodium hydroxide (NaOH), titanium(IV) oxide nanopowder (TiO2, with <25 nm particle size with anatase phase, 99.7% trace metals basis), titanium (IV) oxide mesopowder, chitosan, potassium thiocyanate (KSCN), iron(III) chloride hexahydrate (FeCl2·H2O), and 5-amino-1,3-benzodioxole (97% purity) were purchased from

Morphological analysis

As shown in Fig. 1(a), the PABD- Fe3O4NRs nanocomposite had a strong attraction to the magnet which was evidence that the magnetic Fe3O4NRs were successfully incorporated within the PABD polymer. To further show this effect, a video demonstrating the strong magnetic properties of the nanocomposite was included in the Supplementary Information section (Video S1). HR-TEM was performed to characterize the PABD in the presence and absence of the Fe3O4NRs. Fig. 1(b) displays the PABD in the absence

Conclusions

In this study, we synthesized PABD-Fe3O4NRs using a one-step solid-state reaction. The nanocomposite was characterized using TEM, ESEM, and FT-IR which demonstrated successful synthesis and nanorod morphology of the Fe3O4NRs. For the first time, PABD-Fe3O4NRs were then encapsulated within a PAA-G hydrogel in a one-pot polymerization method and sandwiched as a single layer between the photoanode and cathode along with the incorporation of the [FeSCN]2+ complex to create a hybrid nanocomposite

CRediT authorship contribution statement

Celia Ferrag: Conceptualization, Investigation, Methodology, Validation, Writing - original draft, Writing-review & editing. Meissam Noroozifar: Conceptualization, Investigation, Methodology, Validation, Writing - original draft, Writing - review & editing. Ali Reza Modarresi-Alam: Conceptualization, Writing - review & editing. Kagan Kerman: Conceptualization, Methodology, Data curation, Funding acquisition, Project administration, Supervision, Writing - review & editing.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

K. K. acknowledges financial support from the Canada Research Chair Tier-2 award for “Bioelectrochemistry of Proteins” (Project no. 950-231116), Ontario Ministry of Research and Innovation (Project no. 35272), Discovery Grant (Project no. 3655) from Natural Sciences and Engineering Research Council of Canada (NSERC), and Canada Foundation for Innovation (Project no. 35272). The authors also thank Ilya Gourevich from the Centre for Nanostructure Imaging (Department of Chemistry) at University of

References (86)

  • F. Sadegh et al.

    A facile and green synthesis of superparamagnetic Fe3O4@PANI nanocomposite with a core-shell structure to increase of triplet state population and efficiency of the solar cells

    J. Environ. Chem. Eng.

    (2021)
  • X. Jin et al.

    High-efficiency platinum-free quasi-solid-state dye-sensitized solar cells from polyaniline (polypyrrole)-carbon nanotube complex tailored conducting gel electrolytes and counter electrodes

    Electrochim. Acta

    (2018)
  • E.M. Ahmed

    Hydrogel: preparation, characterization, and applications: a review

    J. Adv. Res.

    (2015)
  • E. Makhado et al.

    Sequestration of methylene blue dye using sodium alginate poly(acrylic acid)@ZnO hydrogel nanocomposite: kinetic, isotherm, and thermodynamic investigations

    Int. J. Biol. Macromol.

    (2020)
  • K. Balasubramani et al.

    Efficient removal of antidepressant flupentixol using graphene oxide/cellulose nanogel composite: particle swarm algorithm based artificial neural network modelling and optimization

    J. Mol. Liq.

    (2020)
  • C. Ferrag et al.

    Polyacrylamide hydrogels doped with different shapes of silver nanoparticles: antibacterial and mechanical properties

    Colloids Surf. B Biointerfaces

    (2021)
  • E. Caló et al.

    Biomedical applications of hydrogels: a review of patents and commercial products

    Eur. Polym. J.

    (2015)
  • J. Duan et al.

    Multifunctional graphene incorporated polyacrylamide conducting gel electrolytes for efficient quasi-solid-state quantum dot-sensitized solar cells

    J. Power Sources

    (2015)
  • J.J. Chen et al.

    Thermo-responsive properties of poly(N-isopropylacrylamide-co-acrylic acid) hydrogel and its effect on copper ion removal and fouling of polymer-enhanced ultrafiltration

    J. Membr. Sci.

    (2014)
  • S. Khajouei et al.

    DNA hydrogel-empowered biosensing

    Adv. Colloid Interface Sci.

    (2020)
  • G.P. Udayakumar et al.

    Biopolymers and composites: Properties, characterization and their applications in food, medical and pharmaceutical industries

    J. Environ. Chem. Eng.

    (2021)
  • M.J. Caulfield et al.

    Degradation on polyacrylamides. Part II. Polyacrylamide gels

    Polymers

    (2003)
  • S. Yuan et al.

    Multifunctional graphene incorporated conducting gel electrolytes in enhancing photovoltaic performances of quasi-solid-state dye-sensitized solar cells

    J. Power Sources

    (2014)
  • S. Yuan et al.

    Efficient quasi-solid-state dye-sensitized solar cells employing polyaniline and polypyrrole incorporated microporous conducting gel electrolytes

    J. Power Sources

    (2014)
  • S. Yuan et al.

    Conducting gel electrolytes with microporous structures for efficient quasi-solid-state dye-sensitized solar cells

    J. Power Sources

    (2015)
  • J. Zheng

    Graphene tailored polymer gel electrolytes for 9.1%-efficiency quasi-solid-state dye-sensitized solar cells

    J. Power Sources

    (2017)
  • Q. Yang et al.

    A series of conducting gel electrolytes for quasi-solid-state quantum dot-sensitized solar cells with boosted electron transfer processes

    J. Energy Chem.

    (2018)
  • A.K. Gupta et al.

    Synthesis and surface engineering of iron oxide nanoparticles for biomedical applications

    Biomaterials

    (2005)
  • M.J. Russell et al.

    New “party pill” components in New Zealand: the synthesis and analysis of some β-ketone analogues of 3,4-methylenedioxymethamphetamine (MDMA) including βk-DMBDB (β-ketone-N,N-dimethyl-1-(1,3-benzodioxol-5-yl)-2-butanamine)

    Forensic Sci. Int.

    (2011)
  • K. Varaprasad et al.

    Removal of dye by carboxymethyl cellulose, acrylamide and graphene oxide via a free radical polymerization process

    Carbohydr. Polym.

    (2017)
  • C. Ferrag et al.

    Thiol functionalized carbon ceramic electrode modified with multi-walled carbon nanotubes and gold nanoparticles for simultaneous determination of purine derivatives

    Mater. Sci. Eng. C: Mater. Biol. Appl.

    (2020)
  • S. Shabzendedar et al.

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

    React. Funct. Polym.

    (2020)
  • S. Pourjavaher et al.

    Development of a colorimetric pH indicator based on bacterial cellulose nanofibers and red cabbage (Brassica oleraceae) extract

    Carbohydr. Polym.

    (2017)
  • A.R. Modarresi-Alam et al.

    The first report of polymerization and characterization of aniline bearing chiral alkyl group on ring via covalent bond; Poly[(±)-2-(sec-butyl)aniline]

    J. Mol. Struct.

    (2015)
  • 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)
  • C.D. Markert et al.

    Characterizing the micro-scale elastic modulus of hydrogels for use in regenerative medicine

    J. Mech. Behav. Biomed. Mater.

    (2013)
  • D. Geethalakshmi et al.

    CSA-doped PANI/TiO2 hybrid BHJ solar cells – material synthesize and device fabrication

    Mater. Sci. Semicond. Process.

    (2016)
  • S. Pourjavaher et al.

    Development of a colorimetric pH indicator based on bacterial cellulose nanofibers and red cabbage (Brassica oleraceae) extract

    Carbohydr. Polym.

    (2017)
  • Q. Li et al.

    A simple approach of enhancing photovoltaic performances of quasi-solid-state dye-sensitized solar cells by integrating conducting polyaniline into electrical insulating gel electrolyte

    J. Power Sources

    (2014)
  • Q. Li et al.

    Full-ionic liquid gel electrolytes: enhanced photovoltaic performances in dye-sensitized solar cells

    J. Power Sources

    (2014)
  • S. Muthusaravanan et al.

    Phytoremediation of heavy metals: mechanisms, methods and enhancements

    Environ. Chem. Lett.

    (2018)
  • N.S. Lewis et al.

    Powering the planet: chemical challenges in solar energy utilization

    Proc. Natl. Acad. Sci. U.S.A.

    (2006)
  • S.Y. Zong et al.

    Fast simultaneous determination of 13 nucleosides and nucleobases in cordyceps sinensis by UHPLC-ESI-MS/MS

    Molecules

    (2015)
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