In situ FTIR spectroscopy of porous electrode materials using ATR technology

In this paper the feasibility for spectroelectrochemical investigation of porous electrodes by means of in situ ATR technique is demonstrated. The charge/discharge behaviour of a Ni(OH)(2)/NiOOH electrode prepared by pressing Ni(OH)(2) powder onto a nickel mesh was evaluated in an appropriate spectroelectrochemical cell modified for in situ ATR measurements. To follow the change in the chemical composition, the intensity of the sharp band at 3640 cm(-1) being characteristic for the stretching fundamental of the free hydroxyl group in beta-Ni(OH)(2) was continously monitored. As this band is absent in the hydrogen-bonded structure of beta-NiOOH the intensity of it was used as a measure for the amount of Ni(OH)(2) which changes during polarization of the electrode. The results have shown that there is a close correlation between electrode potential and normalized difference in reflectivity Delta R/R at 3640 cm(-1).