Capture and utilization of carbon dioxide is one of the important strategies for reducing greenhouse gas emissions. The capture of CO₂ onto solid sorbents is receiving increasing attention. In recent years, different lithium ceramics have been tested as possible CO₂ adsorbents. However, majority of materials systems exhibit sorption capacities much lower than the corresponding theoretical capacities and slow kinetics necessary for practical use. Here, nanowire forms of several lithiated ceramics have been tested for their carbon dioxide sorption capacities and kinetics. The nanowire morphology provides smaller length scale in diameter for complete lithium utilization for carbon dioxide capture.

Li₄SiO₄ nanowire (NWs) powders exhibited an uptake of 0.35 g g^–1 of CO₂ at an ultrafast adsorption rate of 0.22 g g^–1 min^–1 at 650–700 °C.¹ The time scales for CO₂ sorption using nanowires are approximately 3 min and two orders magnitude faster compared to those obtained using lithium silicate powders with spherical morphologies and aggregates. Furthermore, Li₄SiO₄ nanowire powders showed reversibility through sorption–desorption cycles indicating their suitability for CO₂ capture applications.

The presentation will also highlight our recent results with other nanowire materials with CO₂ sorption at temperatures around 100 C.

Acknowledgements: Support from National Science Foundation (NSF) EPSCoR program (1355438).

References:

1. Nambo, J. He, V. Atla, T. Q. Nguyen, T. Druffel, and M. Sunkara, “Ultrafast carbon dioxide sorption kinetics using lithium silicate nanowires”, 17 (6), 3327–3333, Nano Letters (2017).