The supercritical drying procedure was performed in a Jumbo Critical Point Dryer 13200JAB (SPI Supplies). Before the supercritical drying process, all samples were soaked in dry acetone for 2 days (solvent was refreshed every 12 h) and placed in POR3 filter crucibles. The drying chamber was first cooled to 17 • C and the filter crucibles containing the samples were placed inside. The chamber was filled with liquid CO 2 and regularly purged for 3 days (multiple times per day). The temperature was then raised to 37 • C, resulting in a chamber pressure of around 80 bar. Once the temperature and pressure were stable, the chamber was left overnight at these conditions. The CO 2 cylinder equipped with a siphon tube was closed, and the pressure was released from the drying chamber. The samples were transferred into an Ar-filled glovebox and handled further under an inert atmosphere.