5.3 Experimental validation of the concept 85
Figure 5.7: SEM micrographs of MnO2 and Ti-MnO2 lms. a) Surface of asprepared
MnO2. b) Surface of a tested MnO2 lm. c) Surface of as-prepared Ti-MnO2
lm. d) Surface of tested Ti-MnO2 lm. All images are taken with the FEI Helios
EBS3 Microscope at DTU CEN and were acquired by Katarzyna Janik. Acceleration
voltage was 3 kV and beam current 0.17 nA.
lm is shown and there are no dramatic changes to observe. In fact, the tested
Ti-MnO2 surface looks similar to the as-prepared MnO2 surface and appears
slightly more dense than the surface of the tested MnO2 in gure 5.7b. Overall,
these images serve to show that: a) The thin lms surfaces are not perfectly at
but consist of small nanoplates which are not likely to introduce a high roughness,
b) modication with Ti does not lead to changes in surface morphology,
which facilitates straighforward comparison of the electrochemical results and
c) electrochemical testing of these samples does not seem to induce dramatic
changes in the surface structure.