Corona assisted gallium oxide nanowire growth on silicon carbide. - In: Journal of crystal growth, Bd. 509 (2019), S. 107-111
https://doi.org/10.1016/j.jcrysgro.2018.12.033
Cooperative passive coherent location: a promising 5G service to support road safety. - In: IEEE communications magazine, ISSN 1558-1896, Bd. 57 (2019), 9, S. 86-92
https://doi.org/10.1109/MCOM.001.1800242
Plasma hydrogenated TiO2/nickel foam as an efficient bifunctional electrocatalyst for overall water splitting. - In: ACS sustainable chemistry & engineering, ISSN 2168-0485, Bd. 7 (2019), 1, S. 885-894
Im Titel ist "2" tiefgestellt
Electrochemical water splitting is one of the most efficient technologies for hydrogen production and fabrication of low-cost, robust, and highly active electrocatalysts. It is attractive because replacing noble metal-based materials is a key issue in current catalysis research. By using H2 plasma treatment, the TiO2/nickel foam composite is converted to be an efficient bifunctional electrocatalyst toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the alkaline electrolyte. The investigation reveals the existence of abundant oxygen vacancies of TiO2, which might lead to the dramatic improvement of electrical conductivity and faster charge transfer rate; also, density functional theory (DFT) calculations suggest that the oxygen vacancies activate surrounding surface lattice oxygen to induce favorable reactive-intermediate adsorption energy of TiO2 for hydrogen evolution and adjust the strength of the chemical bonds between the TiO2 surface and reactive intermediates to more favorable values, inducing a lower energy barrier for oxygen evolution. The finding confers a unique function to TiO2 that is different from its widely accepted role as an electrocatalytically inert semiconductor material, suggesting the H2 plasma treated TiO2/nickel foam could be a bifunctional electrocatalyst for overall water splitting.
https://doi.org/10.1021/acssuschemeng.8b04496
Collection optimization of photo-generated charge carriers for efficient organic solar cells. - In: Journal of power sources, ISSN 1873-2755, Bd. 412 (2019), S. 465-471
https://doi.org/10.1016/j.jpowsour.2018.11.063
Mathematical modeling of friction stir welding considering dry and viscous friction. - In: Applied mathematical modelling, Bd. 67 (2019), S. 1-8
Corrigendum: Bd. 77 (2020), part 1, page 981
https://doi.org/10.1016/j.apm.2018.10.014
Charge transport in GaAs nanowires: interplay between conductivity through the interior and surface conductivity. - In: Journal of physics, ISSN 1361-648X, Bd. 31 (2019), 7, 074004, insges. 7 S.
https://doi.org/10.1088/1361-648X/aaf515
Exciting vibrons in both frontier orbitals of a single hydrocarbon molecule on graphene. - In: Journal of physics, ISSN 1361-648X, Bd. 31 (2019), 6, S. 065001, insges. 9 S.
https://doi.org/10.1088/1361-648X/aaf54c
Optimizing hydrogen evolution activity of nanoporous electrodes by dual-step surface engineering. - In: Applied catalysis, ISSN 1873-3883, Bd. 244 (2019), S. 87-95
https://doi.org/10.1016/j.apcatb.2018.11.036
Enhancing potassium-ion battery performance by defect and interlayer engineering. - In: Nanoscale horizons, ISSN 2055-6764, Bd. 4 (2019), 1, S. 202-207
Defect and interlayer engineering is applied to exploit the large van der Waals gaps of transition metal dichalcogenides for potassium-ion batteries (KIBs). As a demonstrator, MoS2 nanoflowers with expanded interlayer spacing and defects in the basal planes are used as KIB anodes in the voltage range of 0.5–2.5 V, where an intercalation reaction rather than a conversion reaction takes place to store K-ions in the van der Waals gaps. The nanoflowers show enhanced K-storage performance compared to the defect-free counterpart that has a pristine interlayer spacing. Kinetic analysis verifies that the K-ion diffusion coefficient and surface charge storage are both enhanced in the applied voltage range of the intercalation reaction. The collective effects of expanded interlayer spacing and additionally exposed edges induced by the in-plane defects enable facile K-ion intercalation, rapid K-ion transport and promoted surface K-ion adsorption simultaneously.
https://doi.org/10.1039/C8NH00305J
Thermocapillary convection during hydrogen evolution at microelectrodes. - In: Electrochimica acta, ISSN 1873-3859, Bd. 297 (2019), S. 929-940
The origin of strong electrolyte flow during water electrolysis is investigated, that arises at the interface between electrolyte and hydrogen bubbles evolving at microelectrodes. This Marangoni convection was unveiled only recently (Yang et al., PCCP, 2018, [1]) and is supposed to be driven by shear stress at the gas-liquid interface caused by thermal and concentration gradients. The present work firstly allows a quantification of the thermocapillary effect and discusses further contributions to the Marangoni convection which may arise also from the electrocapillary effect. Hydrogen gas bubbles were electrolytically generated at a horizontal Pt microelectrode in a 1MH2SO4 solution. Simultaneous measurements of the velocity and the temperature field of the electrolyte close to the bubble interface were performed by means of particle tracking velocimetry and luminescent lifetime imaging. Additionally, corresponding numerical simulations of the temperature distribution in the cell and the electrolyte flow resulting from thermocapillary stress only were performed. The results confirm significant Ohmic heating near the micro-electrode and a strong flow driven along the interface away from the microelectrode. The results further show an excellent match between simulation and experiment for both the velocity and the temperature field within the wedge-like electrolyte volume at the bubble foot close to the electrode, thus indicating the thermocapillary effect as the major driving mechanism of the convection. Further away from the microelectrode, but still below the bubble equator, however, quantitative differences between experiment and simulation appear in the velocity field, whereas the temperature gradient still matches well. Thus, additional effects must act on the interface, which are not yet included in the present simulation. The detailed discussion tends to rule out solution-based effects, generally referred to as solutal effects, whereas electrocapillary effects are likely to play a role. Finally, the thermocapillary effect is found to exert a force on the bubble which is retarding its departure from the electrode.
https://doi.org/10.1016/j.electacta.2018.11.187