CO2 adsorption on pure and oxidised Ni nano-structures deposited on mica surfaces

Adsorption and desorption of CO2 on metallic and oxidised Ni nano-structures supported on mica (muscovite) substrates have been studied by temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Predominantly physisorption was observed at low temperatures near 130 K. Weak desorption features were found at temperatures up to about room temperature for both metallic and oxidised samples. No clear indication of dissociation of CO2 was found on neither the oxidised nor the metallic sample. More CO2 was observed to adsorb on oxidised Ni nano-structures as compared to the metallic structures. A large affinity to adsorption of CO from the ambient vacuum was seen on the nano-structures. An absence of strong dependence on Ni amount on CO2 adsorption is reported.