1. Investigation of Fe’s influence on turquoise hydrogen production enhanced by Ni nanoclusters with gamma alumina supportAinars Knoks, Izabela Čurković, Danjela Kuščer, Šarūnas Varnagiris, 2026, izvirni znanstveni članek Povzetek: One of the challenging aspects of implementing hydrogen is the cost and availability of hydrogen, e.g. green hydrogen is costly and inaccessible, whereas conventional grey hydrogen is associated with substantial CO2 emissions. An intermediate solution could be turquoise hydrogen, which promises substantially lower direct cost and CO2-imposed social cost. This work investigates nickel nanoclusters on iron co-catalyst system, supported by gamma alumina, for the catalytic degradation of methane. A novel synthesis approach is tested to examine the influence of Fe amount on reaction yields and outcomes. Varying amounts of Fe with and without Ni were tested at 700,800, and 900 °C in a batch-type reaction. Analysis of catalysts and outcomes was carried out; it was found that the use of co-catalysts on commercial gamma alumina pyrolysis yields hydrogen at 82% at lower reaction temperatures of 700 °C and 80% at900°C. Addition of Ni nanoclusters provide higher results than those of a single Fe catalyst. The synergistic effect of Ni-Fe catalysts exhibits improved efficiency, yielding a range of valuable nanofibrous carbon tested as pesticide sensors showing promise in extending life cycle of catalyst materials.
Ključne besede: iron-nickel nanoclusters, clean energy, hydrogen, pyrolysis, nanomaterials
Objavljeno v DiRROS: 14.05.2026; Ogledov: 194; Prenosov: 155
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2. Insights into surface microstructural engineering of Inconel 625 for enhanced oxygen evolution reaction performanceLuka Suhadolnik, Črtomir Donik, Blaž Tomc, Mejrema Nuhanović, Martin Šala, Marjan Bele, Matjaž Finšgar, Andraž Mavrič, Iztok Arčon, Matjaž Godec, Nejc Hodnik, 2025, izvirni znanstveni članek Ključne besede: electrocatalysis, compositionally complex materials, commercial nickel alloys, oxygen evolution reaction, scanning electron microscopy, IL-SEM
Objavljeno v DiRROS: 29.10.2025; Ogledov: 732; Prenosov: 468
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3. Tribo-corrosion properties of a NiTi dental wirePetra Močnik, Tadeja Kosec, 2014, izvirni znanstveni članek Povzetek: NiTi-alloy arch wires are used in dental medicine for tooth positioning. Failures are reported during the mounting and operation. It is supposed that these difficulties are results of a simultaneous presence of corrosion and mechanical wear. First, a corrosive medium was examined in order to simulate the conditions in the mouth. Different simulated body fluids were compared with natural saliva using electrochemical methods. The corrosion properties of the NiTi dental wire in the as-received state and without the surface oxide film were studied with electrochemical impedance spectroscopy. Tribo-corrosion tests of NiTi in artificial saliva were performed and a relation between the chemical and mechanical wear was studied. After the experiment, the surface was spectroscopically examined. The relation between the chemical and mechanical wear was determined.
Ključne besede: nickel alloys, titan alloys, simulated saliva, passive film, tribo-corrosion, electrochemical impedance spectroscopy
Objavljeno v DiRROS: 26.09.2025; Ogledov: 741; Prenosov: 360
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4. Composite based on nickel-functionalized carbon nitride and carbon nanotubes as an efficient electrocatalyst for the oxygen evolution reactionNicolò Rossetti, Verónica Celorrio, Goran Dražić, Laura Calvillo, 2025, izvirni znanstveni članek Povzetek: Single metal atom catalysts (SACs) are receiving widespread attention in electrochemical energy conversion reactions due to the rational use of metal resources and maximum atom utilization efficiency. The role of the support in stabilizing the single atoms is crucial for their catalytic stability. Carbon nitride (CN) is an excellent support for SACs but its low electrical conductivity is not appropriate for electrochemical applications. Here, we report an engineered composite material based on multiwall carbon nanotubes (MWCNTs) and single nickel atoms stabilized on CN (Ni–CN) as efficient and robust electrocatalyst for the oxygen evolution reaction (OER). Composites with different mass Ni–CN:MWCNT ratios have been prepared to optimize the contribution of both materials, and characterized by X-ray diffraction, transmission electron microscopy, X-ray absorption, and X-ray photoemission spectroscopy. Results confirmed the self-assembly of both materials and the condensation of the triazine-based structure of CN into heptazine-based onto the MWCNTs’ surface during the synthesis, as well as the presence of single Ni atoms in the composites. The co-presence of NiO nanoparticles was detected for the samples with the highest Ni content. The ratio of NiO nanoparticles to single-atom Ni centers was governed by the Ni–CN:MWCNT ratio employed during synthesis. Electrochemical characterization showed a synergistic effect between Ni–CN and MWCNTs that boosted the OER activity of the composites respect to the individual components. The 1:2 ratio turned out to be the optimal one for the composite preparation, maximizing the combined effects of the catalytic activity of the Ni centers and the electrical conductivity of MWCNTs. The mass activity obtained by this composite was 30 times higher than that of the Ni–CN starting material, attributable to its superior electrical conductivity and improved accessibility of Ni active sites. This study underscores the potential of composite materials to advance SACs toward large-scale application.
Ključne besede: carbon nanotubes, carbon nitride, single atom catalysts, nickel oxygen evolution reaction
Objavljeno v DiRROS: 18.09.2025; Ogledov: 698; Prenosov: 358
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5. Application of atomic force microscopy in preparing Ni-Al layer using a two-stage processNingning Li, Zhenjie Hao, Lei Xu, Xi Chen, Jin Peng, Leyu Wei, Mingqi Tang, Yuping Tong, Zicheng Ling, Yimin Li, 2025, izvirni znanstveni članek Ključne besede: Ni-Al layer, atomic force microscopy, nickel layer, morphology
Objavljeno v DiRROS: 24.04.2025; Ogledov: 931; Prenosov: 554
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6. Effects of Ni content on the microstructure and mechanical properties of alumina/silicon carbide tool compositesTingting Liao, Xiaoya Shen, Fanchang Kong, XinYi Yang, Ruotong Tian, Lin He, Chenyang Zhu, Biao Guo, Pingping Liu, Jiehui Liu, Xi Zhang, 2025, izvirni znanstveni članek Ključne besede: nickel, ceramic composite, toughness
Objavljeno v DiRROS: 24.04.2025; Ogledov: 1241; Prenosov: 492
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8. Resolving a structural issue in cerium-nickel-based oxide : single compound or a two-phase system?Jelena Kojčinović, Dalibor Tatar, Stjepan Šarić, Cora Pravda Bartus, Andraž Mavrič, Iztok Arčon, Zvonko Jagličić, Maximilian Mellin, Marcus Einert, Angela Altomare, Rocco Caliandro, 2024, izvirni znanstveni članek Ključne besede: cerium oxide, nickel oxide, crystallography
Objavljeno v DiRROS: 13.03.2024; Ogledov: 1918; Prenosov: 1394
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9. Recombination of oxygen atoms on the surface of oxidized polycrystalline nickel—temperature and pressure dependencesDomen Paul, Miran Mozetič, Rok Zaplotnik, Jernej Ekar, Alenka Vesel, Gregor Primc, Denis Đonlagić, 2023, izvirni znanstveni članek Povzetek: The recombination of neutral oxygen atoms in the ground state on the oxidized nickel samples was studied experimentally in the range of pressures where the maximum density occurs in weakly ionized low-pressure oxygen plasma, i.e. between 40 and 200 Pa. The recombination coefficient was determined in the flowing afterglow. The source of oxygen atoms was plasma sustained in a quartz tube of inner diameter 4.7 mm by a microwave discharge in the surfatron mode. The recombination coefficient was determined in the afterglow chamber, which was a Pyrex tube with an inner diameter of 36 mm. The density of oxygen atoms in the afterglow chamber was varied by adjusting the discharge power, the gas flow, the pressure, and the position of a recombinator. Such flexibility of the experimental system enabled adjustment of the temperature of the oxidized nickel samples independently from the O-atom density in its vicinity or other parameters. The density of oxygen atoms in the afterglow chamber at various system parameters was determined by the Šorli method, which is reliable, and has an accuracy of about 20%. The recombination coefficient was determined by calorimetry. The coefficient was inversely proportional to the square root of the pressure and exponentially to the sample temperature. Systematic measurements performed at various pressures and temperatures enabled empirical formula, which were explained qualitatively by recombination kinetics.
Ključne besede: heterogenous surface recombination, recombination coefficient, nickel, nickel oxide, temperature
Objavljeno v DiRROS: 30.08.2023; Ogledov: 1592; Prenosov: 936
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10. IoT electrochemical sensor with integrated ▫$Ni(OH)_2–Ni$▫ nanowires for detecting formaldehyde in tap waterŠpela Trafela, Abhilash Krishnamurthy, Kristina Žagar, Urška Kavčič, Igor Karlovits, Beno Klopčič, Sašo Šturm, Kristina Žužek Rožman, 2023, izvirni znanstveni članek Povzetek: Simple, low-cost methods for sensing volatile organic compounds that leave no trace and do not have a detrimental effect on the environment are able to protect communities from the impacts of contaminants in water supplies. This paper reports the development of a portable, autonomous, Internet of Things (IoT) electrochemical sensor for detecting formaldehyde in tap water. The sensor is assembled from electronics, i.e., a custom-designed sensor platform and developed HCHO detection system based on Ni(OH)2–Ni nanowires (NWs) and synthetic-paper-based, screen-printed electrodes (pSPEs). The sensor platform, consisting of the IoT technology, a Wi-Fi communication system, and a miniaturized potentiostat can be easily connected to the Ni(OH)2–Ni NWs and pSPEs via a three-terminal electrode. The custom-made sensor, which has a detection capability of 0.8 µM/24 ppb, was tested for an amperometric determination of the HCHO in deionized (DI) and tap-water-based alkaline electrolytes. This promising concept of an electrochemical IoT sensor that is easy to operate, rapid, and affordable (it is considerably cheaper than any lab-grade potentiostat) could lead to the straightforward detection of HCHO in tap water.
Ključne besede: formaldehyde, electrochemical sensor, nickel, tap water
Objavljeno v DiRROS: 06.06.2023; Ogledov: 1934; Prenosov: 1536
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