Quantitative synchrotron micro-XRF study of CoTSPc and CuTSPc thin-films deposited on gold by cyclic voltammetry

Abstract

Synchrotron radiation X-ray fluorescence (SR-XRF) spectroscopy has been applied for the microscopic characterization of cobalt(II) tetrasulfonated phthalocyanine (CoTSPc) and copper(II) 3,4′,4″,4‴-tetrasulfonated phthalocyanine (CuTSPc) thin films electrochemically deposited on gold electrodes. The deposited thin-film properties have been studied as a function of phthalocyanine concentration in solution during the modification process. The Co and Cu surface concentrations on the modified gold electrodes have been determined on the 20 and 600 μm levels. The SR-XRF quantification procedure and micro-heterogeneity determination of the CoTSPc and CuTSPc thin-films on the gold electrodes have been described in detail. The detailed comparison of scanning SR-XRF results with electrochemical data makes it possible to gain further insight in the mechanism of thin layer growth during the modification procedure.