Photoinduced Electrochemical Effect of Porous BiPOM on TiO2 Photoanode Performance for Dye-Sensitized Solar Cells Application

Abstract In this study, a highly porous bismuth phosphotungstate (BiPOM) was prepared and incorporated onto TiO2 via hydrothermal method and evaluated towards its effect on photoelectrochemical properties of TiO2 photoanode for use in dye sensitize solar cells (DSSCs). The pristine and nanocomposite materials were characterized by XRD, FTIR, Raman, BET, TGA, FESEM, TEM, UV vis DRS, PL, XPS to elucidate their surface, structural and optical properties. The nanocomposites were deposited onto FTO electrode and their electrochemical properties were studied using EIS, LSV, and transient photocurrent. Raman results showed a significant Raman blue shift of the Eg, A1g, and B1g peaks upon addition of BiPOM on TiO2 materials, indicating a strong electrostatic interaction between TiO2 and BiPOM materials. The FESEM and TEM images confirmed presence of porous structures that promote good electron diffusion in DSSCs thus, improving the photo conversion efficiency. The TiO2-BiPOM (6%) exhibited reduced energy band gap (2.26 eV) and enhanced electron recombination characteristics as confirmed by UV-Vis and PL techniques respectively. Additionally, upon photoelectrochemical evaluation, TiO2-BiPOM (6%) exhibited excellent charge transfer resistance, highest current response and lowest recombination rate than its counterparts. Therefore, the TiO2-BiPOM (6%) material was recognized as an ideal material for fabrication of TiO2 based photoanodes due to improved surface morphological properties and electron mobility capacities thus can be extensively investigated for other applications.