We demonstrate, using diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS), that carbon dioxide is sequestered in electrospun metal oxide nanofibers. upon removal of the guide polymers by pyrolysis. Carbon dioxide is not present before pyrolysis and is formed during combustion of the polymer. The sequestration of carbon dioxide within these metal oxide nanofibers does not appear to depend on the particular metal precursor, guide polymer, or synthesis method. (c) 2006 Elsevier B.V. All rights reserved.