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The emerging field of living technologies aims to create new functional hybrid materials in which living systems interface and interact with inanimate ones. Combining research into living technologies with emerging developments in computing architecture has enabled the generation of organic electronics from plants and slime mould. Here, we expand on this work by studying capacitive properties of a substrate colonised by mycelium of grey oyster fungi,Pleurotus ostreatus. Capacitors play a fundamental role in traditional analogue and digital electronic systems and have a range of uses including sensing, energy storage and filter circuits. Mycelium has the potential to be used as an organic replacement for traditional capacitor technology. Here, were show that the capacitance of mycelium is in the order of hundreds of picofarads and at the same time a voltage-dependent pseudocapacitance of the order of hundreds of microfarads. We also demonstrate that the charge density of the mycelium 'dielectric' decays rapidly with increasing distance from the source probes. This is important as it indicates that small cells of mycelium could be used as a charge carrier or storage medium.

In vitro cytotoxicity assessment is indispensable in developing new biodegradable implant materials. Zn, which demonstrates an ideal corrosion rate between Mg- and Fe-based alloys, has been reported to have excellent in vivo biocompatibility. Therefore, modifications aimed at improving Zn's mechanical properties should not degrade its biological response. As sufficient strength, ductility and corrosion behavior required of load-bearing implants has been obtained in plastically deformed Zn-3Ag-0.5Mg, the effect of simultaneous Ag and Mg additions on in vitro cytocompatibility and antibacterial properties was studied, in relation to Zn and Zn-3Ag. Direct cell culture on samples and indirect extract-based tests showed almost no significant differences between the tested Zn-based materials. The diluted extracts of Zn, Zn-3Ag, and Zn-3Ag-0.5Mg showed no cytotoxicity toward MG-63 cells at a concentration of ≤12.5%. The cytotoxic effect was observed only at high Zn

Niniejszy tekst rozpoczyna projekt badaczy poświęcony tym myślicielom, którzy rozważania nad możliwością pomyślenia Boga wiążą z problematyką różnicy. Przewodnie pytanie tych rozważań jest takie oto: jak Bóg pojawia się w horyzoncie zróżnicowanym, a zarazem rozdzielonym przez różnicę pomyślaną zawsze na określony sposób? Jeśli różnica nieuchronnie wpisuje się w myślenie, to jak Bóg wpisuje się w różnicę? Pytanie o Boga prowadzi do następnego: jak w obszarze myślenia o boskości rządzi różnica? Innymi słowy: jak dalece sposób, w jaki pomyślana jest różnica, oddziałuje na kształt myślenia o tym, co boskie? Poszukując odpowiedzi na te pytania pierwszy krok kierujemy w stronę Heideggera. Ze względu na szczególny status jego różnicy ontologicznej i na ślad, jaki wciąż pozostawia ona na myśleniu "w horyzoncie" różnicy, to właśnie od niej rozpoczniemy ruch w stronę różnicowania jako takiego. Pytanie o Boga i różnicę u Heideggera ma w tym tekście następujący kształt: jak Bóg pojawia się w obszarze rozdzielonym przez różnicę między byciem a bytem? Jak różnica ontologiczna wyznacza sposób, w jaki pomyślany jest Bóg? This text begins a research project concerning those thinkers who associate the discussion about the possibility of thinking about God with the problem of difference. The main question of these considerations is this: how does God appear on the differentiated horizon, while torn by difference always conceived in a defined manner? If difference is inevitably inscribed in thought, then how is God inscribed in difference? The question about God leads to another: How does difference rule in reflection on divinity? In other words: How far does the way that difference is conceived affect how we reflect upon the deity? When looking for answers to these questions we take the first step towards Heidegger. Owing to the special status of ontological difference and the trace it leaves on thinking "on the horizon" of difference, it is with this we begin movement toward differentiation as such. The question about God and the difference in Heidegger's thought in this text takes the following form: How does God appear in a sphere divided by the difference between Being and beings? How does ontological difference mark conception of God?

A better control over processes responsible for the photocurrent generation in semiconductors and nanocomposites is essential in the fabrication of photovoltaic devices, efficient photocatalysts and optoelectronic elements. Therefore, new approaches towards photochemical properties tuning are intensively searched for. Among numerous parameters, the photocurrent polarity is of great importance to the overall performance of a device. Usually, the polarity is controlled through an alignment of electronic states/bands, tailoring of applied potential or suitable selection of incident light wavelengths. In most scenarios though, the influence of light intensity is somehow neglected and either some arbitrarily chosen, natural conditions are mimicked or this parameter is varied only in a narrow range. Here we present a ternary nanocomposite in which the persistent photocurrent polarity switching is achieved through changes in the light intensity. We also present arguments suggesting this behaviour is of a general character and should be considered also in other photochemical systems., A better understanding of processes responsible for photocurrent generation in semiconductors and nanocomposites is essential in many applications. Here, authors use a ZnO-based hybrid material to demonstrate an unusual photocurrent switching effect induced by varying irradiation intensities.

In this paper, Zn-3Ag and Zn-3Ag-0.5Mg alloys were studied in terms of applicability as biodegradable implant materials. The performed tensile, compression and bending tests indicate a high strengthening effect induced by the Ag and Mg additions, additionally resulting in grain size refinement. It was shown that sustaining plastic strain during deformation depends on the applied stress causing asymmetric mechanical behavior of the tested Zn-based materials. Electrochemical measurements and immersion tests in Hanks' solution lasting up to 180 days revealed that Ag and Mg contribute to the change of the Zn matrix's open circuit potential and the formation of micro-galvanic cells between the Zn grains and precipitates. The fine-grained microstructure and evenly distributed small precipitates led to uniform corrosion occurring via pit formation on the corroded surface due to intergranular and micro-galvanic corrosion mechanisms. The corrosion rate of the Zn-3Ag-0.5Mg alloy after 180 days was almost twice that of pure Zn and the Zn-3Ag alloy.

The comprehensive results regarding the physicochemical properties of carbonaceous materials that are obtained from pistachio shells support their usage as solid fuels to supply direct carbon solid oxide fuel cells (DC-SOFCs). The influence of preparation conditions on variations in the chemical composition, morphology of the biochar powders, and degree of graphitization of carbonaceous materials were investigated. Based on structural investigations (X-ray diffraction analysis and Raman spectroscopy), it was observed that disordered carbon particles developed during the application of thermal treatments. The use of X-ray fluorescence enabled a comparative analysis of the chemical composition of the inorganic matter in biocarbon-based samples. Additionally, the gasification of carbonaceous-based samples vs. time at a temperature of 850 °C was investigated in a H2O or CO2 gas atmosphere. The analysis demonstrated the conversion rate of biochar obtained from pistachio shells to H2, CH4 and CO during steam gasification. The electrochemical investigations of the DC-SOFCs that were supplied with biochars obtained from pistachio shells were characterized by satisfactory values for the current and power densities at a temperature range of 700–850 °C. However, a higher power output of the DC-SOFCs was observed when CO2 was introduced to the anode chamber. Therefore, the impact of the Boudouard reaction on the performance of DC-SOFCs was confirmed. The chars that were prepared from pistachio shells were adequate for solid fuels for utilization in DC–SOFCs.

In this paper, results concerning electrochemical deposition of Ni-TiO2 composite coatings are presented. The influence of electrode potential, concentration of TiO2 in the electrolyte, as well as the influence of magnetohydrodynamic effect (MHD) on deposition rate, composition, current efficiency, structure, surface states, and coatings surface morphology is described. Electrochemical studies were preceded by thermodynamic analysis of the system. In addition, the electrokinetic potential (ZP) of TiO2 particles in applied electrolyte was determined. Electrodeposited composites contained up to 2.15 wt. pct of TiO2. Depending on the applied electrolysis conditions, the current efficiency recorded up to 31.7 pct for B = 0 T and up to 34.2 for B = 1 T. Electrochemical studies as well as further material characterizations indicated the strong influence of the magnetic field on processes taking place at the electrode surface. Several results indicated that the synthesis process is accompanied by precipitation of nickel hydroxides and nickel hydrides as well as by hydrogen evolution reaction (HER). The obtained coatings were also characterized in order to determine their photoelectrochemical properties.

This research was funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No 768789 as well as by the Polish National Centre of Science under grant no 2017/26/D/ST8/00508. The Institute of Solid State Physics, University of Latvia, as a center of excellence, has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement no. 739508, project CAMART2., A key challenge for carbon dioxide reduction on Cu-based catalysts is its low faradic efficiency (FE) and selectivity towards higher-value products, e.g., ethylene. The main factor limiting the possibilities of long-term applications of Cu-based gas diffusion electrodes (GDE) is a relatively fast drop in the catalytic activity of copper layers. One of the solutions to the catalyst stability problem may be an in situ reconstruction of the catalyst during the process. It was observed that the addition of a small amount of copper lactate to the electrolyte results in increased Faradaic efficiency for ethylene formation. Moreover, the addition of copper lactate increases the lifetime of the catalytic layer ca. two times and stabilizes the Faradaic efficiency of the electroreduction of CO2 to ethylene at ca. 30%. It can be concluded that in situ deposition of copper through reduction of copper lactate complexes present in the electrolyte provides new, stable, and selective active sites, promoting the reduction of CO2 to ethylene. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Published under the CC BY 4.0 license.--//-- This is the published version of the article Bisztyga-Szklarz, M.; Mech, K.; Marzec, M.; Kalendarev, R.; Szaciłowski, K. In Situ Regeneration of Copper-Coated Gas Diffusion Electrodes for Electroreduction of CO2 to Ethylene. Materials 2021, 14, 3171. https://doi.org/10.3390/ma14123171., Polish National Centre of Science 2017/26/D/ST8/00508; H2020 768789; H2020 739508 CAMART2.

This work describes results concerning the corrosion behaviour of Li, Na and Si doped eutectic Zn-Al alloys. Corrosion properties were investigated with the use of several complementary electrochemical techniques: time resolved OCP analysis, potentiodynamic studies, rotating disc electrode (RDE) and electrochemical impedance spectroscopy (EIS). The corrosion potential (Ecorr) and corrosion current (icorr) were obtained using potentiodynamic tests. The corrosion studies revealed that the alloying addition to eutectic Zn-Al resulted in slightly lower corrosion resistance than observed for Zn-Al. The results indicate that the addition of Si reduced corrosion resistance the least, compared to Li and Na.

Titanium dioxide nanocomposites were synthesized in hierarchical architectures with the use of 1,4-dihydroxyanthraquinone photosensitizer. In the first step, the dye was either incorporated into the TiO2 core or adsorbed on its surface. In the subsequent phase, both structures were covered with an outer layer of titanium dioxide. The structure, morphology, aggregation, spectroscopic and electrochemical properties of the synthesized TiO2-based materials are presented with a special emphasis on the photosensitization and the photocurrent switching phenomena which are also discussed within the context of the optical logic gates implementation and fuzzy logic systems operation. We present three different interpretations of the photocurrent action spectra yielding binary, ternary or fuzzy logic circuits.

Presented results describe electrochemistry of Ni2+ complexes with glycinate (Gly−), etylenediamminetetraacetate (EDTA4−), acetate (Ac−), citrate (Cit3−), and formate (HCOO−) ligands in aqueous environment. Electrochemical tests indicated possibility of electrochemical synthesis of nickel films at potentiostatic conditions in Ac−, HCOO−, Gly− and Cit3− based systems. Deposition rate is strongly dependent on applied complexing agent. The highest deposition rate, ca. 1900 ng s− 1 cm− 2 (E = − 1.1 V vs. Ag/AgCl) was observed in system containing formate nickel complexes. Registered potentiostatic current – time curves combined with electrochemical quartz crystal microbalance (EQCM) indicated the highest current efficiency for Gly− based system i.e. 0.75 (954 ng s− 1 cm− 2, E = − 1.1 V vs. Ag/AgCl). Voltammograms and XRD patterns indicated that nickel electrodeposition is accompanied by hydrogen absorption. XPS technique indicated the presence of nickel hydroxides on electrodeposited films surface.

In this paper, we present results concerning the electrochemical deposition of Zn-SiC composite coatings reinforced with nano-, submicro-, and microparticles. The influence of current density, particle size, and ultrasound on functional parameters which are especially important from a practical point of view (i.e., concentration of particles in coatings, current efficiency, morphology, reflectivity, roughness, hardness, and corrosion resistance) are investigated and discussed. Coatings were deposited from commercial, chloride-based electrolytes dedicated for the deposition of Zn coatings in a weakly acidic environment. Electrodeposited composites contained up to 1.58, 4.08, and 1.15 wt. % of SiC for coatings reinforced with nano, submicro, and micrometric particles, respectively. The process proceeded with relatively high efficiency, exceeding 80% in almost all cases. The results indicate that ultrasounds strongly increase Faradaic efficiency and affect the kinetics of electrode processes and the properties of synthesized coatings. Moreover, the obtained results show that it is possible to synthesize composite coatings with slightly higher mechanical properties while retaining corrosion resistance compared to metallic Zn coatings.

Presented results describing properties of alloys deposited at potentiostatic conditions in Ni 2+ – Pd 2+ – Cl − – H 2 O system. Electrolysis parameters were defined based on results of thermodynamic analysis as well as voltammetry coupled with electrochemical quartz crystal microbalance (EQCM). Influence of electrode potential and electrolyte components concentration on alloy composition, morphology and its structure was investigated. Alloys were deposited at different Ni(II) and Pd(II) complexes concentrations. Results indicated possibilities of electrochemical synthesis of alloys of wide composition range. Deposits structure as well as crystallites size were discussed based on results of XRD measurements. Alloys composition was determined with the use of energy dispersive spectroscopy (EDS). Morphology of alloys was characterized with the use of scanning electron microscopy (SEM).

This work presents the description of the electrochemical process of formation thin tellurium layers from citrate acidic solution. The suggested methodology consists in the preparation of stable acidic baths with high content of tellurium, and with the addition of citrate acid. In order to analyse the mechanism of the process of tellurium deposition, the electroanalytical tests were conducted. The tests of cyclic voltammetry and hydrodynamic ones were performed with the use of polycrystalline gold disk electrode. The range of potentials in which deposition of tellurium in direct four-electron process is possible was determined as well as the reduction of deposited Te° to Te2− and its re-deposition as a result of the comproportionation reaction. On the basis of the obtained results, the deposition of tellurium was conducted by the potentiostatic method. The influence of a deposition potential and a concentration of TeO2 in the solution on the rate of tellurium coatings deposition was examined. The presence of tellurium was confirmed by X-ray spectrofluorometry and electron probe microanalysis. In order to determine the phase composition and the morphology, the obtained coatings were analysed with the use of x-ray diffraction and scanning electron microscopy.

Over the last years an increased interest has been seen in the electrodeposition of cobalt and cobalt alloys. An essential challenge in the electrodeposition of cobalt is to control the structure and morphology which, in turn, depends on the preparation conditions. The work presents an assessment of the influence of parameters of cobalt deposition in potentiostatic conditions on the structure and morphology of the obtained deposits surface. The level of development of electrocatalytically deposited cobalt layers was examined through microscope methods with the use of the atomic force microscope. Additionally, the samples structure was analysed using X-radiation. The conducted tests allow drawing the following conclusions. The level of surface development does not depend on the applied potential at which deposition of cobalt is carried out. Deposition at low potentials result in creating, on the surface the mixture of metallic cobalt and hydroxides with high level of surface development. High concentration of cobalt ions in the solution result in obtaining close values of the surface development level irrespective of the applied deposition potential.

The present work concerns studies aiming at determination of optimal parameters of obtaining selenium coatings on a copper substrate through the cathodic reduction from sulphate and citrate solutions. The voltammetric analysis was performed in selected solutions to define electrode reactions within the examined range of potentials as well as an influence of pH on their kinetics. The range of potentials in which selenium is reduced to Se0, and then to Se2- was determined. The next stage was performing several electrolysis, where the working electrode was copper. It was to define an influence of citric acid, sodium sulphate, electrolyte pH and the electrolysis potential on the quality of the obtained coatings. The coatings were analysed with the use of X-ray spectrofluorimetry, X-ray diffraction and scanning electron microscopy.

In this paper, we present the results of the study on the influence of electrolysis conditions including external magnetic field on the properties of Ni–TiO2 composite materials synthesized from a citrate bath. The influence of electrode potential, TiO2 concentration in the electrolyte, as well as the value of magnetic field induction vector on the deposition rate, composition, current efficiency, structure, surface states and morphology of the synthesized coatings is reported. The obtained results indicate possibilities of synthesis of composites containing up to 1.39 wt % of TiO2. Dependent on the applied electrolysis condition current efficiency amounts to from 38.1 to 45.5% for B = 0 T and from 46.3 to 53.1 for B = 1 T. The results of electrochemical studies as well as further characterization of synthesized materials indicate that the presence of the magnetic field strongly influenced the kinetics of the processes responsible for materials formation. Voltammetric, XRD and XPS analyses indicate simultaneous formation of hydrides and hydroxides during electrolysis.

The alkaline copper(II) lactate system is the most popular system applied in the electrochemical synthesis of Cu2O films designed for various purposes. The present work describes step by step the mechanism of electrode reactions accompanying the cathodic polarization of the electrode within a potential range from 0 to −1.0 V in copper lactate based electrolyte. Anodic processes related to the oxidation of products formed during cathodic sweep are also analyzed in detail. The performed studies indicate sequence and mechanisms of reduction of species present in the electrolyte, secondary reduction of products of cathodic reactions as well as oxidation of various species formed at the electrode surface.

Present work describes the influence of silver nanoparticles precursor form as well as the impact of graphene oxide initial concentration on deposition of the silver nanoparticles onto graphene oxide. Borane dimethylamine complex (DMAB) was used as the reducing agent. It was observed that application of silver ammonia complexes as the silver nanoparticles precursor as well as alkaline solution effect in higher quantity of deposited AgNPs in comparison to deposition process with the use of silver(I) nitrate in acidic solution.

The kinetic studies of sorption and reduction of gold(III) chloride complex ions on activated carbon Norit ROX 0.8 were carried out. Experiments were performed at different initial concentrations of gold(III) chloride complex ions, agitation rates, temperature as well as initial mass of the adsorbent. SEM, XRD and XPS analyses have confirmed the presence of metallic gold on the activated carbon surface. XPS analysis showed that reduction of gold(III) ions is accompanied by the oxidation of phenolic hydroxide superficial groups. Kinetic equation of a first-order reaction was found suitable for process description.

The work describes the mechanism responsible for formation of Co–Ru alloys through electroreduction of aquachloro complexes of Co(II) and Ru(III) in an aqueous acidic chloride electrolyte of pH = 3. Identification of electrode reactions was performed based on voltammetric and electrogravimetric tests. Potential range for alloy deposition and current efficiency of electrolysis were determined by EQCM and voltammetric tests, respectively. UV–Vis spectrometry was used to examine electrolyte stability. The influence of concentration of various forms of Co(II) and Ru(III) complexes (Σ[CoCl x (H 2 O) 6− x ] 2− x ( x = 0, 1, 2) (10–100 mM), Σ[RuCl y (H 2 O) 6− y ] 3− y ( y = 3,4, 5, 6) (10 mM) as well as applied potential (from −0.5 to −0.9 V vs Ag/AgCl electrode), pH of electrolyte (1–3) and temperature range (25–70 °C) were examined towards composition, structure and morphology of deposited Co–Ru alloys. The performed structural analysis showed a high influence of the synthesis conditions on the structure and morphology of the obtained alloys.

The process of electrochemical deposition of tellurium was studied. Preliminary researches embrace the voltammetry and microgravimetric measurements. According to the results the electrolysis of tellurium was conducted under potentiostatic conditions. There was no deposition of tellurium above potential −0.1 vs. Ag/AgCl electrode in 25°C. The process of deposition is observed in the range of potentials −0.1 to −0.3 V vs. Ag/AgCl. The presence of tellurium was confirmed by XRF and XRD. The obtained deposits were homogenous and compact. Below potential −0.3 V vs. Ag/AgCl the Faradaic efficiency of the tellurium deposition decreased due to reduction of Te to H2Te and hydrogen evolution.

A composite material consisting of metallic platinum nanoparticles and reduced graphene oxide was successfully obtained in microflow reactor. Moreover, subnanometric platinum particles were observed. Reduced graphene oxide plays an important role as a stabilizing agent for platinum nanoparticles. Reduced graphene oxide coverage and platinum particle size as well as size distribution depend mainly on initial concentration of platinum(IV) ions. High level of reduced graphene oxide coverage by platinum nanoparticles (PtNPs) was obtained and is equal to 71%. This in turn effects significantly the mass ratio of reduced graphene oxide to PtNPs which is equal to 49% (w/w). Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis of the obtained materials were performed. Also, catalytic properties of the obtained composite material consisting of PtNPs at reduced graphene oxide surface, towards electrochemical glucose oxidation, were investigated. It was found that the studied materia...

Semiconductors based on selenium are an important class of semiconducting systems which have been widely studied due to their electronic and optical properties. Among them the special attention is focused on molybdenum-selenium system now. The molybdenum chalcogenides are potential electrode materials for photovoltaic and photoelectrochemical applications due to their light absorbing properties in the visible region. Moreover this material has also been used as a catalyst for hydrogen evolution reaction instead of expensive platinum. Usually, thin films of these materials are prepared by high temperature and vacuum techniques. However electrodeposition has been found to be a very good and low-cost method to fabricate thin films of these compounds. The electrodeposition of thin films of Mo-Se phases from aqueous baths were studied. The effect of different concentrations of selenious acid, sodium molybdate, pH and temperature were examined. Additionally different complexing agents embracing ammonia and citrate were tested. A conventional three-electrode cell: Pt-sheet as counter electrode and Saturated Calomel Electrode (SCE) or Ag/AgCl as reference electrodes were used. The different substrates were used as working electrode: gold, copper and ITO. Electrodeposition mechanism and kinetics of Mo-Se system deposition were studied by the conventional electrochemical methods. Chronoamperometry and cyclic voltammetry techniques were combined with electrochemical quartz crystal microbalance to analyze this process in details. According to the obtained results the potentiostatic conditions were applied to deposit Mo-Se thin-films. The proper adjustment of the process of electrolysis has a crucial role on the composition and structure of the deposited films, which decide about their properties. The applied potential of electrolysis were changed systematically in ranges within which it significantly effects on the composition and structure of the Mo-Se thin films. The composition and the structure of the deposited thin films were identified by XRF, EDS, XRD and grazing incidence XRD techniques. Moreover the morphology of the samples were analyzed by SEM. This work was supported by the Polish National Center of Science under grants 2011/01/D/ST5/05743, 2011/01/N/ST5/05509 and AGH University of Science and Technology contract no. 11.11.180.509.

A series of materials based on titanium dioxide nanoparticles and anthraquinone dyes have been modelled using the quantum mechanical minimalistic model. Based on the computational results some spectral and photoelectrochemical properties of these materials have been predicted. Experimental studies indicate that the quantum-chemical predictions are correct. New materials exhibit interesting switching properties and moderate photosensitization towards visible light. Furthermore, based on excited state properties of dye–semiconductor hybrids diverse photocatalytic properties, including the activation of molecular oxygen, can be predicted.

The work describes the mechanism responsible for formation of Co–Rh alloys through electroreduction of aquachloro- complexes of Co(II) and Rh(III) in an acidic chloride electrolyte. The identification of electrode reactions was performed based on voltammetric and electrogravimetric tests. Also, current efficiency of electrolysis was estimated. The electrolyte stability was tested with the use of UV–Vis spectrometry. The potential range enabling the alloy synthesis was based on electrochemical studies. The tests included influence of concentration of ∑ [CoCl x (H 2 O) 6 − x ] 2 − x (x = 0, 1, 2) (10 to 100 mM) and ∑ [RhCl y (H 2 O) 6 − y ] 3 − y (y = 4, 5, 6) (10 mM), electrode potential (− 0.5 to − 1.0 V vs Ag/AgCl electrode), electrolyte pH (1 to 3) and temperature (25 to 75 °C) on the composition, structure and morphology of Co–Rh alloy deposited at various potentials. The conducted tests indicate a possibility of alloy synthesis of a wide range of elemental composition and diversified morphology. The performed structural analysis showed a high influence of the synthesis conditions on the structure of the synthesized alloys.

Recently a number of articles concerning subjects related to limitation of greenhouse gasses emission or neutralization of greenhouse gasses present in atmosphere significantly increased. Global warming negatively influences on non-failure operation of ecosystem and due to glaciers melting resulting in water volume increase causing raising of water level in seas and oceans. Large number of negative factors resulting from global warming effect creating necessity of performance of intensified investigations going to development of technologies enabling limitation of emission or neutralization of greenhouses gasses through its conversion to chemical compounds which can be applied in synthesis of other useful chemical compounds or functional materials. Other important problem beyond limitation of CO2 amount in atmosphere is related to possibilities of its conversion to chemical compounds which can be used as energy carriers. It creates possibilities for its applications in renewable energy storage oriented systems. The proposed project is focused on photoelectrochemical conversion of one of main greenhouse gas, CO2 to ethylene. The main scientific objective of performed studies was the development of methodology for electrochemical synthesis of binary composite Cu-Cu2O material. Copper is the only metal that exhibits very high selectivity for electrochemical conversion of CO2 to ethylene (1). Ren et al. observed similar effect in case of p-type Cu2O (2). Reported effects allow assumption that combination of both materials can be great solution in the frame of light supported electrochemical conversion of carbon dioxide to ethylene. Authors describe optimization of electrochemical synthesis process towards synthesis of composite coatings of wide composition range. Synthesis conditions were investigated starting from the thermodynamic analysis of the electrolyte. Conditions for synthesis were determined based on the results of voltammetric tests and electrochemical quartz crystal microbalance analyses. Synthesized coatings were characterized towards their composition, structure, morphology and catalytic properties towards electrochemical reduction of CO2 to ethylene. References Y. Kwon, Y. Lum, E. L. Clark, J. W. Ager and A. T. Bell, ChemElectroChem, 3, 1012 (2016). D. Ren, Y. Deng, A. D. Handoko, C. S. Chen, S. Malkhandi and B. S. Yeo, ACS Catalysis, 5, 2814 (2015). P. D. Tran, S. K. Batabyal, S. S. Pramana, J. Barber, L. H. Wong and S. C. J. Loo, Nanoscale, 4, 3875 (2012).

The work presents results of the studies on the synthesis of Co–Pd alloys from acid electrolytes containing chloride ions. The main aim of the tests was to identify reactions responsible for alloy formation and to determine an influence of the electrolysis parameters, i.e. working electrode potential, electrolyte composition and temperature on the composition of the resulted alloy coatings. Electrochemical investigations were performed by applying cyclic voltammetry (CV) combined with electrochemical quartz crystal microbalance (EQCM). The electrolyte composition was selected based on a thermodynamic analysis and spectrophotometric tests which were described in our previous papers [1, 2]. They allowed determination of equilibrium distribution of the metals complex forms and a stability analysis of the electrolyte. The alloys were synthesized within the potential range from −0.7 to −1.1 V. The tests indicate a possibility of alloys synthesis already at the potential range < −0.5 V. The alloys composition was analysed with the use of the EDS technique. The obtained alloys featured Pd content from 0.84 to 71.37 at.%.

Investigations of the influence of electrolysis parameters such as the concentration of metal ammonia complexes, working electrode potential and temperature on the composition, structure and catalytic activity of synthesized alloys for water molecule reduction reaction in 2 M NaOH (T = 25 °C) were conducted. The alloys were deposited under potentiostatic conditions within potential range from −0.7 to −1.1 V in electrolytes of pH 9.5, containing ammonia complexes of cobalt(III) and palladium(II), [Co(NH3)6]3+ and [Pd(NH3)4]2+, of different concentration ratio. Structural changes in electrodeposited alloys were discussed based on results of X-ray diffraction measurements. An elemental analysis was performed using the energy-dispersive X-ray spectroscopy technique. Finally, based on results of galvanostatic measurements, the Tafel slope within the range of activation control for hydrogen evolution reaction was determined and mechanism of the process was discussed. The alloys presented low Tafel slope value, from 25.4 to 88.7 mV dec−1. The alloy of the highest activity for hydrogen evolution reaction contained 31.2 at.% of Pd.

The main aim of the studies was to establish the parameters of electrolysis corresponding to the lowest value of overpotential of HER (hydrogen evolution reaction). The influence of sodium tungstate concentration, arginine concentration and orientation of applied magnetic field (MF) on composition, morphology, structure, cathodic current efficiency of deposition process and electrocatalytic activity of deposited alloys was examined. Carbon addition to electrodeposited Co–W alloys was made to enhance the electrolytic activity of hydrogen evolution process in 8 mol dm −3 NaOH at 90 °C. The alloys were deposited at pH = 4. The concentration of Na 2 WO 4 ·2H 2 O corresponding to the best catalytic activity of the obtained Co–W and Co–W–C alloys was 25 g/l. The positive effect of carbon addition on catalytic activity of hydrogen evolution was observed. The influence of electrodeposition parameters on size of microcracks formed during deposition processes was also investigated.

This work comprises results of the studies on the mechanism and kinetics of hexaamminecobalt(III) and tetraamminepalladium(II) co-reduction in ammonia–chloride solutions at pH 9.5. Electrolyte stability was determined by UV–Vis absorbance measurements. Electrochemical investigations were performed by applying cyclic voltammetry (CV) combined with electrochemical quartz crystal microbalance (EQCM) as well as with spectrophotometric measurements. The results indicated that the reduction process of [Co(NH3)6]3+ consists of two steps. In the first step [Co(NH3)6]3+ is reduced to [Co(NH3)4]2+ and [Co(NH3)5]2+, and then ammonia complexes of Co2+ are reduced to Co0. The M/z values determined during electrogravimetric measurements indicate that the reduction process of [Pd(NH3)4]2+ takes place in one step due to 2-electrons irreversible reduction reaction. Deposition of Co and Pd take place only in the overpotential deposition range. It was found that the examined reactions are diffusion-controlled. In anodic part M/z values and registered CV's indicate cobalt(II) hydroxide oxidation.

The work presents studies of the mechanism and kinetics of tetraamminepalladium(II) electro-reduction in ammonia – chloride solutions at pH = 9.5. The studies were preceded by the thermodynamic analysis of the electrolyte. The electrolyte stability was determined by UV–Vis absorbance measurements. Electrochemical examinations were performed by applying cyclic voltammetry (CV) combined with electrochemical quartz crystal microbalance (EQCM). The M / z values determined during electrogravimetric measurements indicate that reduction process of [Pd(NH 3 ) 4 ] 2+ occurs in one step due to 2-electrons irreversible reduction reaction. Deposition of Pd takes place only in the overpotential deposition range. The examined reactions are diffusion controlled. Diffusion coefficient of [Pd(NH 3 ) 4 ] 2+ participating in particular reactions was determined with the use of Berzins–Delahay equation.

The work comprises results of the studies on the mechanism and kinetics of hexaamminecobalt(III) reduction in ammonia-chloride solutions at pH 9.5. The studies were preceded by the thermodynamic analysis of the electrolyte. Electrolyte stability was determined by UV–vis absorbance measurements. Electrochemical examinations were performed by applying cyclic voltammetry (CV) combined with Electrochemical Quartz Crystal Microbalance (EQCM) as well as with spectrophotometric measurements. The results indicated that reduction process of [Co(NH 3 ) 6 ] 3+ consists of two steps. In the first step [Co(NH 3 ) 6 ] 3+ is reduced to [Co(NH 3 ) 4 ] 2+ and [Co(NH 3 ) 5 ] 2+ , and then ammonium complexes of Co 2+ are reduced to Co 0 . Deposition of Co takes place only in the overpotential deposition range. Values of electrochemical equivalents M/z within this range indicate formation of Co(OH) 2 phase. The examined reactions are diffusion controlled. Diffusion coefficients of complexes participating in particular reactions were determined with the use of Randles–Sevcik and Berzins–Delahay equations. In anodic part M/z values indicate 2-electrons reaction of cobalt oxidation connected with chemical dissolution of cobalt hydroxide formed during cathodic sweep.

Co-Mo and Co-Mo-C Alloys Deposited in a Magnetic Field of High Intensity and their Electrocatalytic PropertiesThe article presents results of tests on electrodeposition in a magnetic field of Co-Mo and Co-Mo-C alloys characterised by low overvoltage of hydrogen evolution. Addition of molybdenum and carbon was to lower the values of overvoltage of hydrogen evolution on cobalt. The influence of a magnetic field of high intensity (1 - 12 T) on the deposits composition, structure and morphology was determined. The deposition was conducted in a magnetic field of parallel orientation of the magnetic field forces lines in relation to the working electrode. Electrocatalytic properties of the obtained alloy coatings within the range of hydrogen evolution were tested in a concentrated solution of NaOH. The obtained alloys were analysed with the XRD method, their composition was tested with the WDXRF technique and they underwent observation applying scanning electron microscopy (SEM). The comparison of electrocatalytic properties of Co-Mo alloys with properties of Co-Mo-C ones enabled determining the influence of carbon presence in cathodic deposits on the overvoltage value of hydrogen evolution on them.

The main scientific objective of performed studies was development of methodology for electrochemical synthesis of ternary composite materials in the Cu-Cu2O-CNT/CNF systems (CNT – carbon nanotubes, CNF – carbon nanofibers). Copper is the only metal that exhibits very high selectivity for electrochemical conversion of CO2 to ethylene (1). Ren et al. observed similar effect in case of p-type Cu2O (2). Reported effects allows on assumption that combination of both materials can be great solution in the frame of light supported electrochemical conversion of carbon dioxide to ethylene. Additionally application of carbon structures: CNT or CNF as charge transfer mediators can limit photodegradation of Cu2O, improving simultaneously its chemical stability (3) and catalytic activity as well as selectivity for electrochemical conversion of CO2 to ethylene (2). Presence of highly hydrophobic CNT/CNF phase in Cu matrix may significantly improve selectivity through limiting adsorption of polar water molecules favoring simultaneously adsorption of nonpolar CO2 molecules. Present studies describing optimization of electrochemical synthesis process towards synthesis of composite coatings of wide composition range. Synthesis conditions were investigated starting from thermodynamic analysis of the electrolyte. In next step, based on zeta potentials values stability of colloidal electrolyte containing carbon nanotubes was analyzed. Current-voltage conditions allowing on deposition of Cu with Cu2O with simultaneous incorporation of CNT/CNF structures were determined based on voltammetric and elctrogravimetric tests. Synthesized coatings were characterized towards their composition, structure and morphology. References Y. Kwon, Y. Lum, E. L. Clark, J. W. Ager and A. T. Bell, ChemElectroChem, 3, 1012 (2016). D. Ren, Y. Deng, A. D. Handoko, C. S. Chen, S. Malkhandi and B. S. Yeo, ACS Catalysis, 5, 2814 (2015). P. D. Tran, S. K. Batabyal, S. S. Pramana, J. Barber, L. H. Wong and S. C. J. Loo, Nanoscale, 4, 3875 (2012).

The electrodeposition of cadmium on silver was analysed by cyclic voltammetry, electrochemical quartz microbalance and electrochemical impedance spectroscopy. All the techniques complemented each other and specify the range of potentials where underpotential and bulk deposition take place. Additionally, the CV and EIS measurements suggest the phase transformation in the range of potentials where the phenomenon of UPD phenomenon is indicated. Keywords: Underpotential deposition, Electrochemical quartz crystal microbalance, Electrochemical impedance spectroscopy, Cadmium, Silver

The work presents results of researches over the deposition of Ni-Mo alloys through the electrolysis conducted in galvanostatic conditions. In order to improve adhesion and aesthetic properties of the deposited alloys, SLS was added to the bath as a surface active agent. The influence of electrolyte pH was tested as well as concentrations of particular components on the composition, structure, cathodic current efficiency of the electrolysis process and catalytic activity of alloys in the process of hydrogen evolution. A positive influence of addition of molybdenum on catalytic activity was observed occurring in lowering the Tafel’s slope within the activation control range from 122 mV/dec (Ni) to 21 mV/dec (Ni-28.5Mo) for a reaction of water molecules reduction in 8 M NaOH at 90°C.

Synthesis of NiPd alloy is investigated in many research centers in the world mainly due to its interesting properties making possible its application as magnetic and catalytic materials. NiPd alloys were investigated also as catalysts in autothermal reforming of methane (1), counter electrode electrocatalyst in liquid-junction solar cells (2), utilization of CO2 and methane in dry reforming process (3), anodes in methanol oxidation (4) and toluene hydrogenation (5). Exchange current density versus the enthalpy of hydrogen adsorption (Log(i0)-dGMe-H) dependence allows on assumption that material composed of Ni and Pd will exhibit high catalytic properties towards hydrogen evolution reaction (HER). Previously we reported studies on electrochemical co-deposition of nickel with palladium from acidic solutions containing aquachloro- complexes of both elements (6) as well as palladium with cobalt (7, 8) and nickel with molybdenum (9). In literature, in spite of its wide application range, few reports exist concerning electrodeposition of NiPd alloys. Existing reports are focused on synthesis of NiPd alloys from suplphate-chloride (5), ethylenediamine (4) and chloride (6) based baths. In present work authors reported studies focused on electrochemical deposition in alkaline ammonia based system for first time. Described studies were started from thermodynamic and UV-Vis analysis enabling qualitative description of analysed system. Electrochemistry of Ni2+ – Pd2+ – Cl– – NH3 – H2O system was analyzed based on results of cyclic voltammetry combined with electrochemical quartz crystal microbalance (EQCM). In further step synthesized alloys were characterized towards their compositions (WD-XRF), morphology (SEM, AFM), structure (XRD) and catalytic properties towards HER. References 1. I. Z. Ismagilov, et al., International Journal of Hydrogen Energy(2014). 2. P. Yang, C. Ma and Q. Tang, Electrochimica Acta, 184, 226 (2015). 3. B. Steinhauer, et al., Applied Catalysis A: General, 366, 333 (2009). 4. K. S. Kumar, et al., Surface and Coatings Technology, 202, 1764 (2008). 5. K. Chen, et al., Chinese Journal of Catalysis, 17, 352 (1996). 6. K. Mech, et al., Applied Surface Science(2016). 7. K. Mech, et al., J Appl Electrochem, 44, 97 (2014). 8. K. Mech, et al., Electrochimica Acta, 104, 468 (2013). 9. K. Mech, et al., Archives of Metallurgy and Materials, 58, 227 (2013).