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Surface patterning of liquid metals (LMs) is a key processing step for LM‐based functional systems. Current patterning methods are substrate specific and largely suffer from undesired imperfections—restricting their widespread applications. Inspired by the universal catechol adhesion chemistry observed in nature, LM inks stabilized by the assembly of a naturally abundant polyphenol, tannic acid, has been developed. The intrinsic adhesive properties of tannic acid containing multiple catechol/gallol groups, allow the inks to be applied to a variety of substrates ranging from flexible to rigid, metallic to plastics and flat to curved, even using a ballpoint pen. This method can be further extended from hand‐written texts to complex conductive patterns using an automated setup. In addition, capacitive touch and hazardous heavy metal ion sensors have been patterned, leveraging from the synergistic combination of polyphenols and LMs. Overall, this strategy provides a unique platform to manipulate LMs from hand‐written pattern to complex designs onto the substrate of choice, that has remained challenging to achieve otherwise.

Liquid metals can play an essential role in the generation of electrically conductive composites for electronic devices and environmental sensing and remediation applications. Here, a method for growing a polyaniline nanofibrous network at liquid metal nanoparticle interfaces is demonstrated for generating hybrid liquid metal–polymer nanocomposites. The investigation shows that an initial functionalization step of the liquid metal nanoparticles with a polymerization enhancer is essential for providing stable and specific nucleation points for the formation of the polyaniline nanofibrous network. The acidity and mechanical agitation conditions are carefully adjusted to control the fibrous polyaniline. The embedded gallium elements form an initial seeding layer around the liquid metal nanoparticles. The novel nanocomposites offer synergistic properties for environmental sensing and molecular separation applications. This study provides a road map for the direct synthesis of long organic molecular chains at the dynamic interfaces of liquid metals.

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Metal foams are highly sought-after porous structures for heterogeneous catalysis, which are fabricated by templating, injecting gas, or admixing blowing agents into a metallic melt at high temperatures. They also require additional catalytic material coating. Here, a low-melting-point liquid metal is devised for the single-step formation of catalytic foams in mild aqueous environments. A hybrid catalytic foam fabrication process is presented via simultaneous chemical foaming, melting, and sintering reaction of liquid metal nanoparticles. As a model, nanoparticles of tertiary low-melting-point eutectic alloy of indium, bismuth, and tin (Field's metal) are processed with sodium hydrogen carbonate, an environmentally benign blowing agent. The competing endothermic foaming and exothermic sintering reactions are triggered by an aqueous acidic bath. The overall foaming process occurs at a localized temperature above 200 °C, producing submicron-to micron-sized open-cell pore foams with conductive cores and semiconducting surface decorations. The catalytic properties of the metal foams are explored for a range of applications including photo-electrocatalysis, bacteria electrofiltration, and CO 2 electroconversion. In particular, the Field's metal-based foams show exceptional CO 2 electrochemical conversion performance at low applied voltages. The facile process presented here can be extended to other lowtemperature post transition and transition metal alloys.

(10 of 11)www.advmat.de www.advancedsciencenews.com steps in the pre-edge region of the XAS spectra (10 167-10 347 eV), 0.25 eV steps in the XANES region (10 347-10 417 eV). In the extended X-ray absorption fine structure region spectra were collected, in steps of 0.035k to a maximum of 10k, with count time increasing linearly from 2 up to 4 s at the end of the energy range. Multiple scans were collected for each sample. Data were preprocessed using Sakura (in-house program) and the Athena program for scan averaging, background subtraction, and edge-height normalization (Ravel and Newville, 2005). Periodically throughout the experiment, transmission scans were collected of the in-line Re foil.