123 research outputs found
Introducing RSC Mechanochemistry
Co-Editors-in-Chief James Batteas and Tomislav FriÅ”ÄiÄ introduce RSC Mechanochemistry
Modularity in Organic Solid State and Supramolecular Chemistry
Connection between the concept of modularity and how it relates to both organic solid state and supramolecular chemistry is discussed. It is demonstrated how the interrelationship between the three areas can be exploited to control chemical reactivity in the solid state. Specifically, it is shown how these areas can be used to achieve and fine-tune reactivity in organic solids. How modularity relates to other chemical systems, as well as to other areas of technology, is also discussed
Electrochemically deposited transition metal dichalcogenide heterostructures as electrocatalysts:Accelerated kinetics for the hydrogen evolution reaction
Transition metal dichalcogenide (TMD) heterostructures have been discovered to have improved catalytic activity towards the hydrogen evolution reaction (HER). This study explores the stability and HER catalytic activity including reaction kinetics of heterolayers of different TMDs (MoS2, MoSe2 and WS2). The stability of the heterolayers varied with those having an overlayer of electrodeposited MoS2 being more stable as compared to those with MoSe2 overlayer which degraded with each scan in acidic media. Investigation into the HER kinetics of the heterolayers involved Tafel analysis and electrochemical rate constant calculation. There was an improvement in Tafel values calculated in comparison to reported values for these heterolayers. WS2/MoS2 and MoSe2/MoS2 heterolayers registered rate constants of (3.20 Ā± 0.10) Ć 10ā4 cm sā1 and (1.73 Ā± 0.03) Ć 10ā4 cm sā1 respectively, which was an improvement of up to an order of magnitude compared to the reported rate constant of electrodeposited MoS2 of (3.17 Ā± 0.30) Ć 10ā5 cm sā1. All this highlights the improved HER catalytic activity of the heterolayers.</p
Thermal relaxation and quantum tunnelling of the magnetization in Mn_12-acetate
The dependence of the magnetic moment m on the temperature T and the magnetic field H in a synthesized molecular magnet Mn_12-acetate has been measured using a SQUID magnetometer. The splitting of zero-field cooled (ZFC) and field-cooled (FC) m(T) curves below the so-called blocking temperature TB ( ā 3.6 K at H = 0) was observed. By measuring the time relaxation of m, it was found that it tended to the same value with the same relaxation time ( ā 560 s at 3 K) for both ZFC and FC processes. This indicates spin freezing below TB and the single molecule process in the explored temperature range (2 K < T < 4 K). The dependence of TB on applied H was also investigated. The decreasing of TB with increasing H can be explained in the frame of barrier reduction in the applied field
TermiÄka relaksacija i kvantno tuneliranje magnetizacije u Mn12-acetatu
The dependence of the magnetic moment m on the temperature T and the magnetic field H in a synthesized molecular magnet Mn12-acetate has been measured using a SQUID magnetometer. The splitting of zero-field cooled (ZFC) and field-cooled (FC) m(T) curves below the so-called blocking temperature TB (ā 3.6 K at H = 0) was observed. By measuring the time relaxation of m, it was found that it tended to the same value with the same relaxation time (ā 560 s at 3 K) for both ZFC and FC processes. This indicates spin freezing below TB and the single molecule process in the explored temperature range (2 K <T < 4 K). The dependence of TB on applied H was also investigated. The decreasing of TB with increasing H can be explained in the frame of barrier reduction in the applied field.Mjerili smo ovisnost magnetskog momenta m sintetiziranog molekulskog magneta Mn12-acetat o temperaturi T i magnetskom polju H pomoÄu SQUID magnetometra. Ispod tzv. temperature koÄenja TB (ā 3.6 K pri H = 0) primijetili smo razdvajanje krivulja m(T) za uzorak hlaÄen bez polja (ZFC) i hlaÄen u polju (FC). Mjerenja vremenske relaksacije m pokazuju da m teži istim vrijednostima s jednakim relaksacijskim vremenima (ā 560 s na 3 K) za oba procesa, ZFC i FC. NareÄeno ukazuje na zamrzavanje spinova ispod temperature koÄenja TB (ā 3.5 K) i jednoÄestiÄnu prirodu procesa u istraživanom temperaturnom podruÄju (2 K <T < 4 K). Istraživali smo i ovisnost TB o primijenjenom polju H. Pad TB s poveÄanjem H objaÅ”njavamo sniženjem bedema u primijenjenom polju
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