Electropolymerization and application of polyoxometalate-doped polypyrrole film electrodes in dye-sensitized solar cells

The Alphabet of Nanostructured Polypyrrole

This review is devoted to polypyrrole and its morphology, which governs the electroactivity of the material. The macroscopic properties of the material are strictly relevant to microscopic ordering observed at the local level. During the synthesis, various (nano)morphologies can be produced. The formation of the ordered structure is dictated by the ability of the local forces and effects to induce restraints that help shape the structure. This review covers the aspects of morphology and roughness and their impact on the final properties of the modified electrode activity in selected applications.

Efficient dye-sensitized solar cell fabricated using a less toxic alternative to electrolyte and charge collector

The photovoltaic investigation of novel and efficient dye-sensitized solar cells is discussed in this paper. Ruthenium-based synthetic dye (N3) is used as a sensitizer. A less toxic alternative is suggested for toxic indium-based glass substrates by using aluminum-doped zinc oxide (AZO) and fluorine-doped tin oxide (FTO) as charge collectors. Moreover, the electrolyte used is a mixture of polymer (polyaniline) and an iodide-triiodide couple to go for the approach involving a lower amount of iodine. In the paper study, on the extent of light, absorption of dye is done by ultraviolet-visible (UV-vis) spectroscopy. The morphological study of sheets is done using scanning electron microscopic (SEM) images to understand the binding of titania on photoanode. Photovoltaic characteristics (I-V) and induced photon to current efficiency (IPCE) measurements, and light harvesting efficiency (LHE) are also investigated. The highest power conversion efficiency of 6.18% is observed in the suggested fabricated green solar cell. Hence, more efficient, indium-free, and novel cell is fabricated by the usage of different charge collector substrates and quasi solid-state electrolytes.

Role of Polyoxometalate Contents in Polypyrrole: Linear Actuation and Energy Storage

A combination of polyoxometalates with polypyrrole is introduced in this work. Our goal was to include phosphotungstic acid (PTA) in different molar concentrations (0.005, 0.01, and 0.05 M) in the electropolymerization of pyrrole doped with dodecylbenzene sulfonate (DBS) and phosphotungstinates (PT), forming PPy/DBS-PT films. Scanning electron microscopy (SEM) revealed that the PPy/DBS-PT films became denser and more compact with increasing PTA concentrations. The incorporation of PT in PPy/DBS was analyzed using Fourier-transform infrared (FTIR) and energy dispersive X-ray (EDX) spectroscopy. The linear actuation in cyclic voltammetry and potential square wave steps in an organic electrolyte revealed increasing mixed actuation, with major expansion upon oxidation found for PPy/DBS-PT films with a PTA concentration of 0.005 M. Best results of a strain of 12.8% and stress at 0.68 MPa were obtained for PPy/DBS-PT (0.01 M). The PPy/DBS-PT films polymerized in the presence of 0.05 M of PTA and showed main expansion upon reduction, changing the actuation direction. Chronopotentiometric measurements of PPy/DBS-PT samples were conducted to determine the specific capacitance optimal for a 0.01 M PTA concentration in the range of 80 F g⁻¹ (±0.22 A g⁻¹).

Polymers in High-Efficiency Solar Cells: The Latest Reports

Third-generation solar cells, including dye-sensitized solar cells, bulk-heterojunction solar cells, and perovskite solar cells, are being intensively researched to obtain high efficiencies in converting solar energy into electricity. However, it is also important to note their stability over time and the devices' thermal or operating temperature range. Today's widely used polymeric materials are also used at various stages of the preparation of the complete device-it is worth mentioning that in dye-sensitized solar cells, suitable polymers can be used as flexible substrates counter-electrodes, gel electrolytes, and even dyes. In the case of bulk-heterojunction solar cells, they are used primarily as donor materials; however, there are reports in the literature of their use as acceptors. In perovskite devices, they are used as additives to improve the morphology of the perovskite, mainly as hole transport materials and also as additives to electron transport layers. Polymers, thanks to their numerous advantages, such as the possibility of practically any modification of their chemical structure and thus their physical and chemical properties, are increasingly used in devices that convert solar radiation into electrical energy, which is presented in this paper.

Modeling oxidised polypyrrole in the condensed phase with a novel force field

A novel model potential is developed for simulating oxidised oligopyrroles in condensed phases. The force field is a coarse grained model that represents the pyrrole monomers as planar rigid bodies with fixed charge and dipole moment and the chlorine dopants as point atomic charges. The analytic function contains 17 adjustable parameters that are initially fitted on a database of small structures calculated within all-electron density functional theory. A subsequent potential function refinement is pursued with a battery of condensed phase isothermal-isobaric Metropolis Monte Carlo in-silico simulations at ambient conditions with the goal of implementing a hybrid parametrization protocol enabling agreement with experimentally known thermodynamic properties of oxidised polypyrrole. The condensed system is composed of oligomers containing 12 monomers with a 1:3 dopant-to-monomer concentration. The final set of force field optimised parameters yields an equilibrium density of the condensed system at ambient conditions in excellent agreement with oxidised polypyrrole samples synthesised in wet-laboratories.

Five compounds based on [TeMo6O24]6− and [β-Mo8O26]4− anions synthesized by using different symmetrical and asymmetric N-donor ligands

A series of POM-based compounds can be used as amperometric detectors and the compounds based on [β-Mo₈O₂₆]⁴⁻ can not only detect the cation Cr(vi), but also can photocatalytically reduce Cr(vi).