1D ZnO nano-assemblies by Plasma-CVD as chemical sensors for flammable and toxic gases

In this work, 1D ZnO nano-assemblies were prepared on Al2O3 substrates by plasma enhanced-chemical vapor deposition (PE-CVD), and characterized in their morphology and chemical composition by field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDXS) and X-ray photoelectron spectroscopy (XPS). For the first time, the sensing performances of PE-CVD ZnO nanosystems were tested in the detection of toxic/combustible gases (CO, H-2 and CH4), revealing very good responses already at moderate working temperatures. In particular, carbon monoxide and hydrogen detection was possible already at 100 degrees C. whereas methane sensing required a minimum temperature of 200 degrees C. The performances of the present ZnO nanosystems, that make them attractive candidates for technological applications, are presented and discussed in terms of their unique and controllable morphological organization. (C) 2010 Elsevier B.V. All rights reserved.