The effect of TiO₂ nanostructures such as nanoparticles, nanowires, nanotubes on photoanode properties, and dye-sensitized solar cells photovoltaic parameters were studied. The series of dye-sensitized solar cells based on two dyes, that is, commercially N719 and synthesized 3,7′-bis(2-cyano-1-acrylic acid)-10-ethyl-phenothiazine were tested. Additionally, the devices containing a mixture of this sensitizer and chenodeoxycholic acid as co-adsorbent were fabricated. The amount of adsorbed dye molecules to TiO₂ was evaluated. The prepared photoanodes with different TiO₂ nanostructures were investigated using UV-Vis spectroscopy, optical, atomic force, and scanning electron microscopes. Photovoltaic response of constructed devices was examined based on current-voltage characteristics and electrochemical impedance spectroscopy measurements. It was found that the highest UV-Vis absorption exhibited the photoanode with nanotubes addition. This indicates the highest number of sensitizer molecules anchored to the titanium dioxide photoanode, which was subsequently confirmed by dye-loading tests. The highest power conversion efficiency was (6.97%) for solar cell containing nanotubes and a mixture of the dyes with a co-adsorbent.

The work addresses an issue of the conductivity phenomenon in conductive polymer thin films. Polyaniline was chosen as a broadly used and thoroughly investigated conductive polymer in order to test and show capabilities of the developed original approach based on impedance spectra analysis. A number of films of different thickness were deposited onto a Pt electrode surface and consequently investigated in aqueous solution containing perchloric acid as an electrolyte. The processes that occur in polyaniline film were studied by cyclic voltammetry, electrochemical quartz crystal microgravimetry (EQCM) and electrochemical impedance spectroscopy (EIS). The role of incorporated ions as charge carriers was investigated with respect to the control of the conductivity properties of the film. Along with detailed polyaniline behavior study, the work makes up a fundamental scientific impact on theoretical electrochemistry and electroanalytical techniques.

Geopolymers, recognized as an ecological alternative to cement concrete, are gaining more and more interest from researchers and the construction industry. Due to the registrable electrical conductivity, this material also attracts the interest of other fields of science and industry as a potential functional material. The article discusses the used geopolymer material, created on the basis of metakaolin and waste Cathode Ray Tubes (CRT) glass, reinforced with ultra-long in-house carbon nanotubes (CNT), in the context of its use as a smart material for Structural Health Monitoring. Long in-house made carbon nanotubes were added to enhance the electrical conductivity of the geopolymer. The impedance spectroscopy method was applied to investigate the conductive properties of this material. The paper shows the microscopic and mechanical characteristics of the materials and presents the results of promising impedance spectroscopy tests.

A number of commercial organic compounds (m-MTDATA, PBD, CBP, TAPC, NPB, TPBi, etc) as well as several donor-acceptor-donor (D-A-D) compounds were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The compounds were chosen as they are promising components of small-molecule-based high efficiency Thermally Activated Delayed Fluorescence (TADF) emitters in Organic Light Emitting Diodes (OLEDs).\ud \ud Electrochemical impedance spectra of a Pt electrode in CH2Cl2 solutions containing the investigated compound and Bu4NBF4 as the electrolyte were obtained and analyzed by electrochemical electrical circuit methods. Charge transfer resistance, double layer capacitance, Warburg constant and other parameters were determined and represented as a function of the potential. Analysis of charge transfer resistance as a function of potential allowed an estimation of standard redox rate constants for the compounds' oxidation and reduction processes.\ud \ud Two main features concerning the redox reaction rates of OLED-active compounds were revealed: (i) the oxidation and reduction rates of ambipolar compounds, i.e. containing both donor and acceptor parts, were found to be much higher than those of unipolar donor-only and acceptor-only molecules; (ii) the relationship between the oxidation and reduction rate constants was shown to be related to the compounds' conductivity type in the solid state