Au Nanoparticles Effect on Inverted ZnO Nanorods/Organic Hybrid Solar Cell Performance

The sun provides a plentiful and inexpensive source of carbon-neutral energy that has yet to be fully utilized. This is a major driving force behind the development of organic photovoltaic (OPV) materials and devices, which are expected to offer benefits such as low cost, flexibility, and widespread availability. For the photovoltaic performance enhancement of the inverted ZnO-nanorods (NR)/organic hybrid solar cells with poly(3-exylthiophene):(6,6)-phenyl-C61-butyric-acid-methylester (P3HT:PCBM) and poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) active layers, gold nanoparticles (Au-NPs) were introduced into the interface between indium-thin-oxide cathode layer and ZnO cathode buffer layer, and the efficiency improvement was observed. It's worth noting that adding Au NPs had both a positive and negative impact on device performance. Au NPs were shown to be advantageous to localized surface plasmon resonance (LSPs) in the coupling of dispersed light from ZnO NRs in order to extend the light's path length in the absorbing medium. Although the light absorption in the active layer could be enhanced, Au NPs might also act as recombination centers within the active layer. To avoid this adverse effect, Au NPs are covered by the ZnO seeded layer to prevent Au NPs from direct contact with the active layer. The dominant surface plasmonic effect of Au NPs increased the photoelectric conversion efficiency from 2.4% to 3.8%.

Advancements in cathode catalyst and cathode layer design for proton exchange membrane fuel cells

Proton exchange membrane fuel cells have been recently developed at an increasing pace as clean energy conversion devices for stationary and transport sector applications. High platinum cathode loadings contribute significantly to costs. This is why improved catalyst and support materials as well as catalyst layer design are critically needed. Recent advances in nanotechnologies and material sciences have led to the discoveries of several highly promising families of materials. These include platinum-based alloys with shape-selected nanostructures, platinum-group-metal-free catalysts such as metal-nitrogen-doped carbon materials and modification of the carbon support to control surface properties and ionomer/catalyst interactions. Furthermore, the development of advanced characterization techniques allows a deeper understanding of the catalyst evolution under different conditions. This review focuses on all these recent developments and it closes with a discussion of future research directions in the field.

Impact of the Cathode Layer Printing Process on the Performance of MEA Integrating PGM Free Catalyst

In this work, platinum group metal (PGM) free-based cathode active layers were prepared using different printing techniques. The membrane electrode assemblies (MEAs) integrate a PGM free catalyst based on Fe, N and C atoms at the cathode side. Scanning electron microscopy (SEM) images of MEA cross sections showed the strong impact of the fabrication process on the cathode structure, the porosity and the ionomer repartition. The MEAs were characterized in a 25 cm2 single cell using cyclic voltammetry under H2/N2. The performance of the MEAs and the double layer capacity of the cathodes were also shown to be linked to the process used. The comparison of the electrochemical accessible surface of the catalyst and of its surface area (SBET) led to the determination of a utilization factor. The coated membrane (CCM) made using the decal transfer process gives the best performances.

Воздействие импульсного тлеющего разряда атмосферного давления на алюминиевые пленки нанометровой толщины

The effect of a positive pulsed corona discharge on the thin-film cathode surface was studied in atmospheric pressure air gaps of 2–8 mm at voltages of 5–15 kV. Observed current pulses had the following parameters: repetition rate about 10-15 kHz, pulse duration of 300-500 ns, and amplitude of 10-20 mA. It was shown that at relatively low average currents of 20–50 μA, the discharge transforms into the glow one near the cathode. Due to the discharge channel radial contraction to micrometer scale, Joule heating of the formed cathode layer can lead to a temperature increase up to 1000 K and cause local erosion of the cathode surface. This mechanism should be taken into account when analyzing the interaction of discharge plasma with biological objects.

Полимерные комплексы никеля с лигандами саленового типа как многофункциональные компоненты катодов литий-ионных аккумуляторов

This work describes the method of preparation of composite lithium-ion battery cathodes that allows total replacement of conventional polymer binders and electroconductive carbon black additives with redox-active conductive polymeric nickel complexes of salen-type Schiff base ligands in the electrode layer. The structure and electrochemical behavior of the electrodes prepared by this method have been investigated. Polymeric metal complexes have been shown to successfully perform the functions of binding and conductive components and also reversibly store charge in the lithium iron phosphate cathodes, which could result in the improvement of the specific capacity of the cathode layer, as compared with the conventional electrodes.

RESTORATION OF MACHINE PARTS WITH GALVANIZED ZINC COATINGS

The article shows the role of electroplating in the restoration of parts, indicates the advantages of restoring parts with electroplating over other methods, and gives the characteristics and properties of coatings obtained by electroplating. (Research purpose) The research purpose is in increasing the speed of application of zinc electroplating when restoring parts. (Materials and methods) The cathode current density has a decisive influence on the coating speed. The main reason for limiting the cathode current density during galvanizing from sulfuric acid electrolytes is the chemical polarization of the cathode. The article presents a study on the designed installation for the application of galvanic coatings. When applying coatings to the internal surfaces of parts, there was used a device with activating elements having an electromechanical rotation drive. This device prevents depletion of the near-cathode layer of the electrolyte and reduces the chemical polarization of the cathode. Elements made of moisture-resistant skin were used as activators. (Results and discussion) The article presents the results of experiments as a dependence of the coating speed on the speed of the activator relative to the restoring surface. It also presents the relationship between the size of the abrasive grains of the activating elements, the force of their pressing against the cathode surface, the speed of movement of the activator and the speed of applying the zinc coating, as well as its quality. By activating the cathode surface, it was possible to raise the operating current density to 100-150 amperes per square decimeter. The speed of application of zinc coatings is 16-25 micrometers per minute. (Conclusions) In the course of research, authors determined the conditions of electrolysis during galvanizing, which provide a significant increase in the cathode current density and the rate of application of these coatings during the restoration of parts.

Ce0.9Gd0.1O2−x for Intermediate Temperature Solid Oxide Fuel Cells: Influence of Cathode Thickness and Anode Functional Layer on Performance

The performances of Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) anode-supported planar cells with a 10 cm2 active surface were studied versus the combination of cathode thickness and the presence of an Anode Functional Layer (AFL). The temperature range was 500 to 650 °C, and Gd0.1Ce0.9O2−x (GDC) was used as the electrolyte material, Ni-GDC as the anode material, and La0.6Sr0.4Co0.2Fe0.8O3−d (LSCF48) as the cathode material. The power density, conductivity, and activation energy of different samples were determined in order to investigate the influence of the cathode thickness and AFL on the performance. These results showed an improvement in the performances when the AFL was not present. The maximum power density reached 370 mW·cm−2 at 650 °C for a sample with a cathode thickness of 50 µm and an electrolyte layer that was 20 µm thick. Moreover, it was highlighted that a thinner cathode layer reduced the power density of the cell.

Polyethylenimine-Ethoxylated Interfacial Layer for Efficient Electron Collection in SnO2-Based Inverted Organic Solar Cells

In this work, we studied inverted organic solar cells based on bulk heterojunction using poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C71-butyric acid methyl ester (P3HT:PCBM) as an active layer and a novel cathode buffer bilayer consisting of tin dioxide (SnO2) combined with polyethylenimine-ethoxylated (PEIE) to overcome the limitations of the single cathode buffer layer. The combination of SnO2 with PEIE is a promising approach that improves the charge carrier collection and reduces the recombination. The efficient device, which is prepared with a cathode buffer bilayer of 20 nm SnO2 combined with 10 nm PEIE, achieved Jsc = 7.86 mA/cm2, Voc = 574 mV and PCE = 2.84%. The obtained results exceed the performances of reference solar cell using only a single cathode layer of either SnO2 or PEIE.