Inspired by our recent finding that Fe4.5Ni4.5S8 rock is a highly active electrocatalyst for HER, we set out to explore the influence of the Fe:Ni ratio on the performance of the catalyst. We herein describe the synthesis of (Fe x Ni1–x )9S8 (x = 0–1) along with a detailed elemental composition analysis. Furthermore, using linear sweep voltammetry, we show that the increase in the iron or nickel content, respectively, lowers the activity of the electrocatalyst toward HER. Electrochemical surface area analysis (ECSA) clearly indicates the highest amount of active sites for a Fe:Ni ratio of 1:1 on the electrode surface pointing at an altered surface composition of iron and nickel for the other materials. Specific metal–metal interactions seem to be of key importance for the high electrocatalytic HER activity, which is supported by DFT calculations of several surface structures using the surface energy as a descriptor of catalytic activity. In addition, we show that a temperature increase leads to a significant decrease of the overpotential and gain in HER activity. Thus, we showcase the necessity to investigate the material structure, composition and reaction conditions when evaluating electrocatalysts.

In this work, we present detailed investigations on the influence of binary ionic liquid (IL) mixtures on sol−gel syntheses of metastable metal oxide phases. The synthesis of the metastable TiO 2 bronze phase and anatase as well as the rutile modification is followed via in situ diffraction methods coupled with thermal gravimetric analysis. The variation of the composition of mixtures of ILs allows for the adjustment of TiO 2 phase composition at low temperatures. On the basis of these results, the synthesis of the hexagonal tungsten bronze-like titanium hydroxyl oxy fluoride was achieved. Our results pave the way for a deeper understanding of IL participation in the syntheses of inorganic nanomaterials, going further than treating them as solvents.

Recent experimental investigations demonstrated the generation of singlet oxygen during charging at high potentials in lithium/oxygen batteries. To contribute to the understanding of the underlying chemical reactions a key step in the mechanism of the charging process, namely, the dissociation of the intermediate lithium superoxide to oxygen and lithium, was investigated. Therefore, the corresponding dissociation paths of the molecular model system lithium superoxide (LiO2) were studied by CASSCF/CASPT2 calculations. The obtained results indicate the presence of different dissociation paths over crossing points of different electronic states, which lead either to the energetically preferred generation of triplet oxygen or the energetically higher lying formation of singlet oxygen. The dissociation to the corresponding superoxide anion is energetically less preferred. The understanding of the detailed reaction mechanism allows the design of strategies to avoid the formation of singlet oxygen and thus to potentially minimize the degradation of materials in alkali metal/oxygen batteries. The calculations demonstrate a qualitatively similar but energetically shifted behavior for the homologous alkali metals sodium and potassium and their superoxide species. Fundamental differences were found for the covalently bound hydroperoxyl radical.

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Запропоновано методику мічення бактерій гібридним фторвмісним блок-кополімером з фрагментом олігонуклеотида та детектування методом мас-спектроскопії вторинних іонів. Синтетичні олігомери для створення блок-кополімеру на основі оліго (N-вінілпіролідону) отримано методом радикальної полімеризації. Як ініціюючу Red-Ox систему використано сіль Ce 4+ та фторалкільні спирти лінійної будови різної довжини. Структуру олігомерів підтверджено методами ІЧ-та ЯМР-спектроскопії. Досліджено вплив довжини фторалкільного блока на колоїдно-хімічні властивості одержаних олігомерів. Підтверджено можливість мічення бактерій отриманим природно-синтетичним блок-кополімером. Ключові слова: радикальна полімеризація, сіль церію, фторвмісні олігомери, фторалкільний спирт, агент передачі ланцюга, олігонуклеотид.