A complementary Raman and SECM study on electrically conductive coatings based on graphite sol-gel composite electrodes for the electrochemical antifouling

The surface of electrically conductive coatings based on a sol-gel lacquer with graphite as conductive additive that were developed for the use in marine antifouling technology was examined with two powerful surface characterization techniques, namely Raman microscopy and scanning electrochemical microscopy (SECM). These two methods provide information about the distribution of compounds as well as conductivity. A correlation of these two techniques reveals that not all conductive material contributes equally to the overall conductivity. Furthermore, the coating was examined with respect to its spatially resolved electrocatalytic activity towards the evolution of chlorine and oxygen which are the main active molecules generated during electrochemical stress. The comparison of the very same area showed electrocatalytically active hot spots with higher rate of generation of these species compared to the value averaged over the electrode area, and the results correlate to conductivity and graphite particle distribution.