Nature: The nanotubes helped to turn water vapour and carbon dioxide inside a chamber into methane.Nano Lett. Researchers have used sunlight to convert carbon dioxide and water vapour into a range of fuels faster than ever before, thanks to a nanotube catalyst. Materials scientist Craig Grimes and his colleagues at Pennsylvania State University in University Park have used hollow titania (titanium dioxide) nanotubes around 135 nanometres wide and a tenth of a millimetre long to …