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In the final Alchemist column of 2016, we hear about less than noble catalysts for hydrogen production, supplementary elemental analysis, mercury in Canadian seabirds, material exfoliation to make electrides, and observe the precise moment of crystallization. Finally, two visiting professors headed for Germany.
The simple-seeming process of exfoliation has allowed materials scientists to shave an unusual class of ionic solids down to two-dimensional layers of electrides. These highly conductive nanosheets might find applications in electronics and chemical synthesis. Electrides are layered ionic solids in which atomic planes are separated by delocalized electron sheets. They are often referred to as a "2D electron gas" and have electrical conductivity higher than that other famous 2D material graphene.
Scientists have for the first time observed at the molecular level the instant at which a solution undergoes a transition and a crystalline solid appears. The observation corroborates recent theories about the process of crystallization, but also shows that if one knows how a crystal starts growing it could be possible to predict the final structure. Organic chemist Ronny Neumann of the Weizmann Institute and his colleagues used electron microscopy to observe the formation of dense phases and the subsequent transformation of these phases into crystal nuclei.
An outstanding chemist and an outstanding theoretical physicist have been awarded visiting professorships by the Graduate School of Excellence "Materials Science in Mainz" (MAINZ), German. Chemist Egbert Willem Meijer of Eindhoven Technical University in the Netherlands and RIKEN's Gen Tatara, will take on the roles. The professors' input will be in the form of lectures, seminars, and workshops to help train doctoral candidates at MAINZ. Meijer is one of the worldï¿½s leading scientists in the field of supramolecular chemistry while Tatara works in spin physics, a field of research with a focus on the intrinsic angular momentum of electrons.
A more tenable approach to hydrogen production could facilitate the emergence of the so-called hydrogen economy thanks to work on water splitting by an international team. Manashi Nath of Missouri University of Science and Technology and her colleagues have used a nickel-selenium coordination complex as an "earth abundant" catalyst rather than the more common noble metal catalysts for the electrolytic splitting of water.
Scientists in Spain have used a sequential analytical approach based on high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) to determine concentrations of essential metals in beverages and dietary supplements including calcium, copper, iron, magnesium, manganese, and zinc. The approach is amenable to a straightforward analysis of these elements but can also determine silicon, which is rarely considered in nutritional data.
Levels of mercury found in seabirds off the coast of British Columbia, have remained relatively stable over the past half a century despite rising levels of the problematic metal in the environment. The finding by a team at McGill University is explained on the basis that surface-dwelling fish numbers have fallen considerably in that time and this has forced the birds to alter their diets and to feed in areas low in sulfate-reducing bacteria and it is this environmental factor which leads to the lower level of mercury in their bodies. "Clearly, what is happening at the base of the food web reverberates up to the top of the food web," says Kyle Elliott.