Comparison of Electrospun Titania and Zinc Oxide Nanofibers for Perovskite Solar Cells and Photocatalytic Degradation of Methyl Orange Dye

Abstract

ZnO and TiO2 are both well-known electron transport materials; however, an exact comparison of their performance, when fabricated under the same synthesis conditions, is missing in the literature. Considering this, we introduced a viable electrospinning route for the development of highly polycrystalline TiO2 and ZnO nanofibers for an electron transport material (ETM) of perovskite solar cells and photocatalysts for textiles. Thanks to the effective tuning of band structure and morphology of TiO2, a significant improvement in performance as compared to ZnO was observed when both were used as photoanodes and photocatalysts. X-ray diffraction detected polycrystalline structural properties and showed that peaks are highly corresponding to TiO2 and ZnO. Morphological analysis was carried out with a scanning electron microscope, which revealed that nanofibers are long, uniform, and polycrystalline, having diameter in the nano regime. TiO2 nanofibers are more aligned and electron-supportive for conduction as compared to ZnO nanofibers, which are dense and agglomerated at some points. Optoelectronic properties showed that TiO2 and ZnO show absorption values in the range of ultraviolet, and visible range and band gap values for TiO2 and ZnO were 3.3 and 3.2 eV, respectively. The TiO2 band gap and semiconductor nature was more compatible for ETL as compared to ZnO. Electrical studies revealed that TiO2 nanofibers have enhanced values of conductivity and sheet carrier mobility as compared to ZnO nanofibers. Therefore, a higher photovoltaic conversion efficiency and antibacterial activity was achieved for TiO2 nanofibers (10.33%), as compared to ZnO (8.48%). In addition, the antibacterial activity of TiO2 was also recorded as better than ZnO. Similarly, compared to ZnO nanofibers, TiO2 nanofibers possess enhanced photoactivity for antimicrobial and dye degradation effects when applied to fabrics.