Eggshell Membrane-Templated Porous Gold Membranes Using Nanoparticles as Building Blocks

Highly porous gold membrane-like structures are formed using eggshell membrane, as-such and heat denatured, as a template and gold nanoparticles as building blocks. Gold nanoparticles were produced in-situ on the eggshell membranes without using additional reducing agents. The morphology and loading of gold nanoparticles can easily be controlled by adjusting the pH and thus the redox potential of eggshell membranes. Lower pH favored the formation of irregularly-shaped but dense gold macro/nanocrystals whereas higher pH (8 - 9) favored the formation of fairly uniform but less dense gold nanoparticles onto the eggshell membranes. Heat treatment of eggshell membrane - gold nanoparticle composites formed at pH 8 - 9 led to the formation of highly porous membrane-like gold while mimicking the original structure of eggshell membrane. All these materials have been thoroughly characterized using field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and inductively coupled plasma - atomic emission spectroscopy (ICP-AES). These highly porous membrane-like gold materials may have potential applications in catalysis, biosensors, electrode materials, optically selective coatings, heat dissipation and biofiltration.