Synthesis, Characterization, and Application of CeO2, TiO2, ZrO2, and SnO2 Oxides in Dye-Sensitized Solar Cells (DSSCs)

Dye-sensitized solar cells (DSSCs), belonging to the third generation, are highlighted for their low production cost compared to other photovoltaic technologies. These cells are composed of a cathode, an electrolyte, and an anode, commonly using TiO2. This work aims to produce and characterize CeO2, SnO2, and ZrO2 oxides as substitutes for TiO2 in DSSCs. The semiconductor oxides were synthesized using the Pechini methodology and applied as the anode of the system. The device was assembled in a sandwich configuration, with an anode and cathode (graphene), an active area of 0.2 cm2, and an electrolyte containing the I3−/3I− redox pair. The techniques employed included scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray diffraction (XRD), UV-Vis spectroscopy, open-circuit potential curves and electrochemical impedance spectroscopy (EIS). The oxides exhibited good crystallization with non-defined morphology. The obtained band gap values were 2.8 eV, 3.0 eV, 3.1 eV, and 4.8 eV for CeO2, TiO2, SnO2, and ZrO2, respectively. In DSSCs, these oxides showed photosensitivity, generating potential when exposed to light with TiO2-based cell exhibited the lowest charge transfer resistance (Rct = 57.8 kΩ). This comparative framework establishes a preliminary screening of the intrinsic interfacial charge transfer and recombination kinetics of alternative standalone photoanodes, serving as a baseline for future device optimization.