Ammonia-free Gram-Scale Synthesis of Silica Nanotubes for Advanced Proton-Conducting Membranes
The Research group of Prof. Aasheesh Srivastava [Department of Chemistry] in collaboration with Dr. Paramita Das [Department of Chemical Engineering] developed a bio-inspired strategy for the gram-scale synthesis of uniform silica nanotubes using a self-assembling phenylalanine derivative as template. The conventional synthesis of silica nanotubes involves use of ammonia or organic solvents, both of which are undesirable from ecological perspective. Moreover, translating controlled nanostructure formation into scalable production remains a challenge. Here, researchers produced silica nanotubes under mild aqueous conditions without requiring external toxic bases such as ammonia. Their new synthesis protocol allows gram scale synthesis of silica nanotubes using just 7 wt.% of the template in pure aqueous medium. Another key feature of their method is the uniform diameter (around 60 nm) of the nanotubes while their lengths can be in several microns. Author tested if these hollow tubes can act as “highways” for movement of protons in composite polymer electrolyte membranes (CPEMs) that are utilized in fuel cells. Remarkably, incorporating just 0.1 wt% of these nanotubes into a polymeric membrane enhanced the proton conductivity by 45%. The thermal stability of these films was improved by glutaraldehyde crosslinking resulting in stable performance up to 80 °C, the common temperature at which fuel cells work. This work presents a promising green route towards scalable, high-performance CPEMs for potential applications in direct methanol fuel cells (DMFCs)
