Simple Molecules Adsorption Studies on Highly Epitaxial -Pure Phase- Delafossite CuFeO$_{2}$ Thin Films

Carbon dioxide (CO$_{2})$ and hydrogen (H2) adsorption studies on CuFeO$_{2}$ thin films grown on Al$_{2}$O$_{3}$ (00.1) substrates were performed in ultrahigh vacuum using thermal programmed desorption (TPD). Growth of pure phase Delafossite CuFeO$_{2}$ thin films on Al$_{2}$O$_{3}$ (00.1) substrates by pulsed laser deposition was systematically investigated as a function of growth temperature and oxygen pressure. CO$_{2}$ and H$_{2}$ TPD were performed on CuFeO$_{2}$ -grown at 600$^{\circ}$C and in 0.1mTorr pressure- indicating chemisorption of both gases on the oxide surface. TPD with a temperature ramp of 50 K/s showed a CO$_{2}$ peak at 573 K and H$_{2}$ peak at 823 K. The chemisorption of CO$_{2}$ and H$_{2}$ on the CuFeO$_{2}$ surface is relevant to the potential use of this material in photocatalytic applications for H$_{2}$ production and/or CO$_{2}$ conversion.