Next Step: Titanium Dioxide

During my last week of research, I started a new phase of my project. After completing the study of the electron transfer dynamics of the dye Rhodamine 560 on glass, I moved on to studying the behavior of this dye on titanium dioxide. While we can learn a lot from the studies of R560 on glass especially when we compare it to other rhodamine dyes on glass, that entire phase of experimentation was just a control for comparison with the results on titanium dioxide. In actual dye-sensitized solar cells, the application of this research, titanium dioxide or some other semiconductor is necessary for the generation of electricity.

In the past, my lab has always synthesized our own solution of titanium dioxide nanoparticles, but this time we were able to order a suspension of the particles that was already prepared. Unfortunately, the bottle itself didn’t have very much information about the concentration of the solution, so a few emails to the manufacturer were necessary to determine how much of the solution should be used. Even the manufacturer was only able to provide an approximation of the solution’s mass. Once this was figured out, I had to decide between two procedures for adsorbing the R560 solution to the titanium dioxide solution. The method we had used in the past was to spin coat a dye/titanium dioxide solution onto a glass coverslip. This was the same technique we used for dye/glass studies, except we replaced ultrapure water with a solution of titanium dioxide. However, we also found an alternative technique in the literature that involved annealing the dye/titanium dioxide solution to the slide in an oven, then rinsing the slide to get rid of any dye molecules that weren’t chemically bound to the titanium dioxide.

The first time I tried the annealing method, the slide came out covered in brown gunk. This might have been from the inside of the oven, or it could have resulted from the solution being contaminated. When I prepared a new solution and tried again, at a lower temperature, the slide came out of the oven looking clean. However, the microscope scans still showed some contamination. Unfortunately, my time in lab for the summer came to an end before I had the chance to explore this thoroughly, but it will definitely be one of the first issues I revisit at the beginning of the fall semester.2017-07-20 16.02.48