Achievement

IGERT Trainee Sonia Mathew, working with CCNY Professor Ilona Kretzschmar, investigated the formation of porous TiO2 electrodes for dye-sensitized solar cells. She prepared colloidal crystals from sulfated polystyrene particles with diameters ranging from 500 nm - 10 mm. The colloidal crystals were infiltrated with a TiO2 precursor and calcined in a furnace at 450 degrees Celsius leading to formation of inverse opal TiO2 crystals. The opal crystals were characterized the inverse opal TiO2 electrodes using electrochemical methods, by which she has shown that the inverse opal TiO2 electrodes show typical electrode behavior: (i) at a constant scan rate the slope of the cathodic current is constant, while the anodic current increases with more negative potentials; (ii) the anodic current peak moves to positive potentials with increasing scan rate indicating diffusional control; and (iii) pore size dependence of charging behavior.