Co-active impact of surface hydroxyls on the solvation shell and dye adsorption of Mitragyna Speciosa chlorophyll molecules in dye-sensitised solar cells

The co-active effects of dual surface hydroxyl, OH of the protic solvent on the dye adsorption and electron injection efficiency of DSSCs are presented in this study. A few polar protic and aprotic solvents were used in the extraction of chlorophyll-based dye sensitiser from mitragyna speciosa (MS) leaves. The existence of chlorophyll and functional groups was detected through the UV–visible and FTIR spectroscopy. Furthermore, the overall performances of the DSSCs were examined through current-to-voltage characteristics, I-V. It was revealed that all protic solvents produced higher dye adsorption as well as higher photocurrent density, J SC , owing to their higher polarisability, better solvation and enriched surface hydroxyl, OH. Aprotic solvent, on the other hand, has limited and weak surface hydroxyl, OH due to the absence of hydrogen bonding, resulting in less dye adsorption on the TiO 2 nanoparticle. As a result, the amount of dye-adsorbed and J SC was also reduced. It was discovered that MeOH (protic solvent) has finally contributed to the highest photo-conversion efficiency (PCE) of 0.25%.