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Institute
Low pressure capacitively coupled radiofrequency plasmas operated in a mixture of aniline vapor and argon are used for the deposition of thin films on silicon substrates. The influence of the aniline vapor fraction in the gas mixture upon the plasma properties and the characteristics of the deposited thin film is analyzed. Plasmas diagnostics are carried out using mass spectrometry and optical emission spectroscopy and the thin films are characterized by means of Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine-structure spectroscopy. Experiments highlight that the use of a low aniline/argon ratio leads to the deposition of an amorphous film whereas high-aniline/argon ratios allow the synthesis of a plasma polymer similar to polyaniline. The properties of such plasmas and the mechanisms involved in the deposition process are discussed in detail.
The design of novel and abundant catalytic materials for electrolysis is crucial for reaching carbon neutrality of the global energy system. A deliberate approach to catalyst design requires both theoretical and experimental knowledge not only of the target reactions but also of the supplementary mechanisms affecting the catalytic activity. In this study, we focus on the interplay of hydrogen mobility and reactivity in the hydrogen evolution reaction catalyst MoS2. We have studied the diffusion of atomic hydrogen and water by means of neutron and X-ray photoelectron spectroscopies combined with classical molecular dynamics simulations. The observed interaction of water with single-crystal MoS2 shows the possibility of intercalation within volume defects, where it can access edge sites of the material. Our surface studies also demonstrate that atomic hydrogen can be inserted into MoS2, where it then occupies various adsorption sites, possibly favoring defect vicinities. The motion of H atoms parallel to the layers of MoS2 is fast with D ≈ 1 × 10−9 m2/s at room temperature and exhibits Brownian diffusion behavior with little dependence on temperature, i.e., with a very low diffusion activation barrier.
Shaalke: Development of a MATLAB Software Tool for Advanced Statistical Outdoor Data Evaluation
(2025)
This paper introduces Shaalke, a novel analytical software tool developed for the high-accuracy evaluation of long-term photovoltaic module measurement data. Addressing the critical need for robust parameter extraction from field data, Shaalke integrates advanced filtering, linear regression, and algorithmic processing to overcome limitations of traditional evaluation methods. We demonstrate Shaalke's capability to accurately determine STC parameters and both static and dynamic temperature coefficients, showing excellent agreement with manufacturer specifications and independent laboratory measurements. A key finding is Shaalke's precise mapping of the irradiance dependence of module efficiency, filling a significant gap left by typical datasheet values which often only provide data at 1000 and 200 W/m². Furthermore, the tool enables reliable power degradation analysis, identifying modules that exceed manufacturer-tolerated limits. Shaalke provides a comprehensive, data-driven platform for understanding real-world module performance, offering invaluable insights for system design, operation, and quality assurance, thereby bridging the gap between laboratory specifications and field performance.
Electrodeposited Mo-rich NiMo catalysts offer enhanced catalytic activity for the alkaline hydrogen evolution reaction (HER) and provide an electrically conductive, binder-free substrate connection, making them promising catalysts for green hydrogen production. However, creating Mo-rich deposits is challenging, as the codeposition process typically favors Ni. Optimal deposition conditions for Mo-rich NiMo catalysts remain insufficiently explored. This article investigates Mo-rich NiMo electrodeposition from an ammonia-free citrate bath using NaSO4 as a chlorine-free support electrolyte. The effects of the deposition parameters, 1) sodium molybdate concentration in the electrolyte, 2) deposition current density, and 3) enhanced mass transport via working electrode rotation on the alkaline HER activity, were studied. The electrodeposits, containing 44–66 wt% Mo, exhibited increased surface area due to a rough, cracked morphology and variable oxygen content of the catalyst. The oxygen content was linked to HER activity, revealing an inhibiting effect. The lowest overpotential of 118 mV at −10 mA cm−2 for the alkaline HER was achieved using an electrolyte with 0.02 mol L−1 sodium molybdate, a deposition current density of 600 mA cm−2, without electrode rotation. Respective samples combined a favorable Ni:Mo ratio comprising 56 wt% Mo content with increased surface area and low oxygen content.
Die vorliegende Studie untersucht die Auswirkungen dynamischer Stromtarife auf das Stromverbrauchsverhalten und die Gesamtstromkosten in Deutschland im Jahr 2024. Gemäß §41 EnWG sollen dynamische Stromtarife den Stromverbrauch an das wetterabhängige Angebot erneuerbarer Energien (EE) anpassen. Die Studie analysiert 243 Szenarien eines preisgesteuerten Stromverbrauchs, wobei verschiedene Parameter wie das EE-Stromangebot, der minimale Strombörsenpreis und die Verschiebungsperiode des Stromverbrauchs variiert werden. Die Ergebnisse zeigen, dass eine kostenoptimierende Anpassung des Stromverbrauchs nur mit zusätzlichen Kurzzeitspeichern umsetzbar ist, um inakzeptable Verwerfungen im Tagesablauf der Stromverbraucher zu vermeiden. Die Berechnungen verdeutlichen, dass dynamische Stromtarife unter den Bedingungen des Jahres 2024 keine wesentlichen systemischen Vorteile bieten und erhebliche technische und finanzielle Zusatzaufwände erfordern. Die Studie schließt mit der Feststellung, dass die Einführung dynamischer Stromtarife neue Geschäftsmodelle und psychologische Effekte auf die Verbraucher haben könnte, jedoch auch eine neue Form der Stromrationierung darstellt.
Zusammenfassung
Anlass dieser Studie ist die verpflichtende Einführung dynamischer Stromtarife gemäß §41 EnWG. Hierdurch soll ein Paradigmenwechsel im Hinblick auf den Stromverbrauch bewirkt werden: Der Stromverbrauch soll sich künftig bestmöglich an das überwiegend wettergeführte Stromangebot der Erneuerbare-Energien-Quellen anpassen, statt dass sich das Stromangebot wie bisher am Strombedarf orientiert.
Die Studie untersucht, inwieweit dynamische Stromtarife das Stromverbraucher-Verhalten und die Gesamtstromkosten des Jahres 2024 hätten beeinflussen können, wenn diese bereits 2024 deutschlandweit genutzt worden wären.
The study introduces flexible and scalable manufacturing approach for electrodes utilizing boron-doped silicon as conductive support for iridium nanoparticles, addressing the challenges of cost and scarcity associated with noble catalysts for oxygen evolution reaction (OER). Colloidal Ir nanoparticles are synthesized via pulsed-laser ablation (≈4–7 nm) and decorated on B-doped Si (≈100 nm) through electrostatic adsorption. Titanium substrates are ultrasonically sprayed with Si:B – Ir and Ir nanoparticles with very low iridium loading of 12 wt.%. Crystalline Ir phases (Ir(111), Ir(200)) are observed and known to enhance the OER mechanism. Additionally, atom probe tomography confirms that the Si support particles contained 0.03-0.5 at.% of boron throughout the entire particle, while electrical permittivity and through-plane measurements reveal a positive impact of B-doped Si on the electrical conductivity of the nanocatalysts and of the ultralow-loaded catalyst coated Ti substrates (0.12 mgIr cm−2), respectively. Rotating disk electrode results show pronounced oxidation peaks for decorated Ir nanoparticles. The Si:B-Ir 4 nm catalyst exhibits the highest turnover frequency (2.62 s−1) and a competitive electrochemical surface area (25 m2 gIr−1) compared to Si:B-Ir 7 nm (0.96 s−1; 37.5 m2 gIr−1) and Ir black (0.24 s−1; 5 m2 gIr−1). The overall analysis of the parameters highlights a performant catalytic efficiency, through balancing activity and reaction kinetics effectively.
The feed-in of electricity from renewable energies, such as wind or solar power, fluctuates based on weather conditions. This unpredictability due to volatile feed-in can lead to sudden changes in energy generation so that solutions ensuring grid stability need to be implemented. The cooling sector offers the opportunity to create flexibilities for such balancing, with this study focusing on the thermal flexibilities that can be provided by cooling applications. Various cooling-demand profiles are investigated with respect to their load profile and their impact on flexibility is analysed. In addition to the cooling demand, scenarios of different storage dimensions are considered. As a result, it shows that an increasing base-load level and increasing operating-load duration have a negative effect on flexibility, while an increasing full-load duration is beneficial for flexibility. Storage size also has a strong impact as higher storage capacity and storage performance indicate higher flexibility, whereas above a certain size they only provide little added value.
This study presents the correlation between electrolyte pH, surface morphology, chemical speciation and electro-catalytic oxygen evolution activity of additive-free electrodeposited NiFe catalysts for application in anion exchange membrane water electrolysis. Spherical morphologies were identified at pH 0, shifting towards honey-combed structures at pH 4 with increasing surface area, especially at pH 3. Further, the electrolyte pH was found to influence the NiFe composition and electro-catalytic activity. Enhanced OER activity was noted at pH 2 with overpotentials of 214 mV at 10 mA cm−2 and 267 mV at 100 mA cm−2. The results reveal that the electrolyte pH is a parameter not only influencing the morphology but also tailoring the surface area, Fe oxide and Fe hydroxide composition and consequently the catalytic activity. Further, the outcomes highlight the electrolyte pH as a key process parameter that should be adjusted according to the application, and may substitute the addition of electrolyte-additives, proposing a simpler method for improving catalyst electrodeposition.

