Ion-beam sputtered palladium-fluoropolymer nano-composites as active layers for organic vapours sensors

Ion-beam sputtering deposited palladium-fluoropolymer (Pd-CFx) nano-structured composite films have been investigated as active layers for the detection of organic solvents vapours. The composites sensing properties have been studied and compared to those of homologous Au-CFx films by means of ellipsometric and quartz crystal microbalance (QCM) experiments. Differences have been shown between sensitivity, selectivity and response repeatability of Au-CFx and Pd-CFx sensors exposed to organic solvent vapours. X-ray photoelectron spectroscopy (XPS) analysis has revealed strong similarities between the two materials as to the polymer matrix structure, but higher concentration of metal oxides and fluorides in the case of palladium. The results of the analytical characterisation have been used to discuss the performance level of the sensors.