Printable 3D Carbon Nanofiber Networks with Embedded Metal Nanocatalysts

Carbon nanofiber (CNF)-nanocatalyst hybrids hold great promise in fields such as energy storage, synthetic chemistry and sensors. Current strategies to generate such hybrids are laborious and utterly incompatible with miniaturization and large-scale production. Instead, this work demonstrates that Ni-nanoparticles embedded in 3D CNFs of any shape and design can be easily prepared using electrospinning followed by laser carbonization under ambient conditions. Specifically, a solution of Ni(acac)2/Polyimide is electrospun and subsequently a design is printed via CO2 laser (Ni-LCNFs). This creates uniformly distributed small Ni nanoparticles (~ 8nm) very tightly adhered to the CNF network. Morphological and performance characteristics can be directly influenced by metal content and lasing power and hence adapted towards desired performance. Here, Ni-LCNFs are optimized for non-enzymatic electrochemical sensing of glucose with a great sensitivity of 2092 µA mM-1 cm-2 and a detection limit down to 0.3 µM. Its selectivity for glucose versus interfering species (ascorbic and uric acid) is essentially governed by the Ni content. Most importantly, this strategy can be adapted to a whole range of metal precursors and hence provide opportunities for such 3D CNFs nanocatalyst hybrids in point-of-care applications where high performance but also sustainable and low-cost fabrication are of utmost importance.