Electrochemical techniques are used extensively in most of our projects. We synthesize, modify, transfer and polish various surfaces aided by electrochemistry.
Electrochemical grafting of aryl diazonium salts, iodonium salts or triazenes has been developed in our group for surface modification of various metals and carbon materials but we also apply electrochemistry for altering the structure or chemistry of the surface films. Electroanalytical techniques are very sensitive when it comes to studies of surface films. It is quite easy to detect and monitor as few as 1010 molecules (=10-13 moles) in a surface film by ordinary Cyclic Voltammetry (CV). A more complicated techniques, Electrochemical Quartz Crystal Microbalance (EQCM), is used to follow assembling of polymer brushes on surfaces.
Substrates used for synthesizing graphene by chemical vapour deposition (CVD) are often electropolished prior to use. After the synthesis the graphene has to be transferred to an inert surface such as Si/SiO2. We use electrochemistry to first intercalate cations beween the graphene and the CVD substrate. In the second step electrochemical formation of hydrogen bubbles at the metallic surface lifts the graphene off the CVD substrate. Scanning Electrochemical Microscopy (SECM) can be used to examine the quality of the surface films or graphene layers and to pattern the surfaces with a spatial resolution of 10 nm.
Rates at two-dimensional electrodes are often mass transport limited. However with the extension of the electrode into a third dimension is possible by means of surface immobilized redox active polymer brushes, conducting polymers or by hybrid materials. In that instance the scope of electrosynthesis or electrocatalytic processes suddenly becomes very interesting. The electron transport process for such three dimensional electrodes are studied by Electrochemical Impedance Spectroscopy (EIS). In particular, our scientific studies on the electrocatalytic reduction of CO2 will be carried out, characterized and/or evaluated by essentially all the techniques, i.e. CV, EQCM, SECM and EIS.