Optical detection of carbon dioxide adsorption on epitaxial CuFe1-xGaxO2 Delafossite film grown by pulse laser deposition

SURFACE SCIENCE

卷:648

Article

Rojas, S.¹  Joshi, T.²  Wheatley, R. A.¹  Sarabia, M.¹  Borisov, P.²  Lederman, D.²  Cabrera, A. L.¹ 

[1] Pontificia Univ Catolica Chile, Inst Fis, Ave Vicuna Mackenna 4860, Santiago, Chile

[2] W Virginia Univ, Dept Phys & Astron, Morgantown, WV 26506 USA

关键词: Delafossite films;    CO2 adsorption;    X-ray photoelectron spectroscopy;    Optical band gap;    Optical transmission and reflection;    Thermal desorption;   

DOI  :  10.1016/j.susc.2015.10.018

来源: Elsevier

【 摘 要 】

A highly epitaxial delafossite CuFe1-xGaxO2 film was made with pulse laser deposition in high vacuum. The sample thickness was around 48 nm and it was terminated with CuFeO2. This delafossite sample was exposed to a CO2 atmosphere under controlled conditions and chemisorption of CO2 on the surface was observed. Transmittance and reflectance spectroscopies were recorded for the sample post surface heat treatment held in a vacuum chamber (0.05 Kpa) and after exposure to CO2. Both spectra were recorded over a wavelength range of 350-1100 nm. Chemisorption of CO2 was correlated with an increase in transmittance and decrease in reflectance in the pressure range 0-60 kPa. These observations were confirmed with X-ray photoelectron spectroscopy and thermal programmed desorption data obtained in an independent experiment. The CO2 is bound to the surface forming a carboxylate structure via coordination of a bent CO2-delta molecule to a Cu center. (C) 2015 Elsevier B.V. All rights reserved.

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