Recommended reading: Bunsen magazine with focus on molecular water research
Water not only has some well-known anomalies, but is still full of surprises. The first issue 2023 of the Bunsen Magazine is dedicated to molecular water research, from the ocean to processes in electrolysis. The issue presents contributions from researchers cooperating within the framework of a European research initiative in the "Centre for Molecular Water Science" (CMWS). A team at HZB presents results from the synchrotron spectroscopy of water. Modern X-ray sources can be used to study molecular and electronic processes in water in detail.
With their report on "Local and collective properties of water", Annette Pietzsch, Robert Seidel and Alexander Föhlisch from HZB describe insights on the nature of water, gained with synchrotron spectroscopy at BESSY II. For example, water, which is normally a perfect insulator, can become metallic under certain conditions.
Other contributions explain the challenges of desalinating seawater, processes in electrolysis or structures in ice on the nanoscale.
These insights help in the design of even better climate models, in environmental research, the design of drugs and vaccines, but also in the development of novel catalysts for green hydrogen or other important technologies.
Green hydrogen: How photoelectrochemical water splitting may become competitive
Sunlight can be used to produce green hydrogen directly from water in photoelectrochemical (PEC) cells. So far, systems based on this "direct approach" have not been energetically competitive. However, the balance changes as soon as some of the hydrogen in such PEC cells is used in-situ for a catalytic hydrogenation reaction, resulting in the co-production of chemicals used in the chemical and pharmaceutical industries. The energy payback time of photoelectrochemical "green" hydrogen production can be reduced dramatically, the study shows.
Perovskite solar cells from the slot die coater - a step towards industrial production
Solar cells made from metal halide perovskites achieve high efficiencies and their production from liquid inks requires only a small amount of energy. A team led by Prof. Dr. Eva Unger at Helmholtz-Zentrum Berlin is investigating the production process. At the X-ray source BESSY II, the group has analyzed the optimal composition of precursor inks for the production of high-quality FAPbI3 perovskite thin films by slot-die coating. The solar cells produced with these inks were tested under real life conditions in the field for a year and scaled up to mini-module size.
Superstore MXene: New proton hydration structure determined
MXenes are able to store large amounts of electrical energy like batteries and to charge and discharge rather quickly like a supercapacitor. They combine both talents and thus are a very interesting class of materials for energy storage. The material is structured like a kind of puff pastry, with the MXene layers separated by thin water films. A team at HZB has now investigated how protons migrate in the water films confined between the layers of the material and enable charge transport. Their results have been published in the renowned journal Nature Communications and may accelerate the optimisation of these kinds of energy storage materials.