Optical Coatings filter ( pass band 4.76 µm to 5.60 µm ) . Spectra were recorded on a Bruker Vertex 80 spectrometer equipped with a mercury cadmium telluride ( MCT ) detector . Data were collected at 4 cm −1 resolution . Typically , 80 time points were recorded for each experiment . The SP-02 cell was fitted with a glassy carbon working electrode ( diameter 3 mm ) , a platinum counter electrode and a silver wire pseudo - reference electrode . These were attached to a Princeton Applied Research VersaSTAT 3 potentiostat . Data collection was controlled by the Bruker Opus package , interfaced to the potentiostat using a custom Opus3D script and TTL connection . IR data was processed and analysed using Fit_3D ( Dr Simon J. George , Lawrence Berkeley National Laboratory , USA ) and curve fitting was carried out using SciDAVis .