Cellulose Nanofiber Biotemplated Palladium Composite Aerogels

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Noble metal aerogels possess high surface area and tunable porosity, making them suitable for catalytic applications.
• Achieving control over aerogel shape, pore size, and nanofiber diameter is crucial for optimizing electronic conductivity and mechanical integrity in device applications.
• Existing synthesis methods for noble metal aerogels are limited, particularly when utilizing noble metal salts.

Purpose of the Study:

• To present a novel synthesis of palladium aerogels using carboxymethyl cellulose nanofiber (CNF) biotemplates.
• To demonstrate control over aerogel shape, pore size, and electrical conductivity through the use of CNF biotemplates.
• To develop a method for producing robust palladium aerogels for catalytic, sensing, and energy applications.

Main Methods:

• Formation of biotemplate hydrogels via covalent crosslinking of carboxymethylated cellulose nanofibers using EDC and a diamine linker.
• Equilibration of hydrogels in palladium salt solutions, followed by reduction with sodium borohydride.
• Dehydration using ethanol and supercritical drying to yield freestanding palladium aerogels with controlled porosity and nanowire structures.

Main Results:

• Successful synthesis of freestanding palladium aerogels with controlled shape, pore size, and conductivity.
• Scanning electron microscopy revealed three-dimensional nanowire structures.
• X-ray diffractometry confirmed the presence of palladium and palladium hydride phases.

Conclusions:

• The CNF-templated synthesis provides a straightforward route to engineer palladium aerogels with tailored properties.
• These self-supporting aerogels exhibit enhanced electrical conductivity and mechanical robustness.
• The developed method is suitable for producing advanced materials for catalysis, sensing, and energy storage applications.