Germany researchers develop method to help bridge tech gap for ethanol fuel cells
Their work has now been published as a cover story in Angewandte Chemie International Edition, titled “Freeze-Thaw-Promoted Fabrication of Clean and Hierarchically-Structured Noble Metal Gels for Electrocatalysis and Photoelectrocatalysis.”
Researchers found unusual self-healing properties of noble metal gels in their previous work. Inspired by these findings, a freeze-thaw method was developed as an additive-free approach to directly destabilize dilute metal nanoparticle solutions (concentration of 0.2-0.5 mM).
Upon freezing, large aggregates were generated due to the intensified salting-out effects incurred by the dramatically raised local solute concentration; meanwhile, they were shaped at the micrometer scale by in situ formed ice crystals.
After thawing, aggregates settled down and assembled to monolithic hydrogels as a result of their self-healing properties. Purified and dried, clean hydrogels and the corresponding aerogels were obtained.
Category: Research