Octahedral-like Ni0.3Zn0.7Fe2O4-TiO2 nanohybrid material as photoanode of natural dye-sensitized solar cells

Abstract

The impact of adding varying loadings (25-75%) of Ni0.3Zn0.7Fe2O4 (NZF) nanoparticles into a TiO2 photoanode sensitized with both natural and commercial dye molecules is reported herein. The photoconversion efficiency (PCE) of the DSSCs was found to be greatly improved by NZFs. Our findings show that NZF enhanced the PCE of NZF/TiO2-0.5/dye/Pt based DSSC by 51.5% for natural chlorophyll dye (spinach extract) and 33% for commercial ruthenium-based dye (Z-907) at an optimum loading of 50% w/w, compared to TiO2/dye/Pt DSSC devices. According to UV-Vis absorption spectroscopy, BET, and electrochemical impedance spectroscopy studies, higher dye loading, improved electron transportation, and lower electron recombination rates with electrolyte and oxidized dyes contributed to the improved performance of the NZF/TiO2-x hybrids based DSSCs. Based on the results of time-dependent stability studies, the NZF/TiO2-0.5/chlorophyll-based cell maintained 94.7% of its original photoconversion efficiency after 14 days before dropping to 87.8% over 30 days.