Colletotrichum gloeosporioides (endophytic fungi) mediated biosynthesis of TiO2 nanoparticles for high-performance dye-sensitized solar cell

This work reports an environmentally friendly protocol for synthesizing TiO₂ nanoparticles (NPs) by utilizing endophytic fungi, Colletotrichum gloeosporioides (C. gloeosporioides). The fungi isolated from Thevetia peruviana, worked as a bio-capping agent to regulate the growing TiO₂ NPs morphology and agglomeration behavior. The formation of TiO₂ NPs was validated by surface plasmon resonance, observed using UV–vis spectroscopy. Using XRD and HRTEM, the structure, size, and shape of the as-synthesized anatase TiO₂ NPs were characterized. BET analysis was used to examine the surface area and porosity. EIS revealed the greater charge collection efficiency and enhanced electron lifetime for the TiO₂ obtained with N-3 (endophytic fungal extract). The dye-sensitized solar cell (DSSC) fabricated with bio-capped TiO₂ (N-3) photoanode exhibited greater light-to-current conversion efficiency, 3.50 %; much enhanced compared to 0.98 % obtained with un-capped TiO₂ NPs (N-1) based cell. The study demonstrated that the endophytic fungus C.gloeosporioides played a vital role in enhancing the cell performance.