Influence of ethanol on the spectral properties of natural dyes from microbes: implications for dye-sensitized solar cell performance

Abstract

The increasing need for renewable energy sources that are both sustainable and less costly has spurred growing research into natural dyes as eco-friendly sensitizers for dye-sensitized solar cells (DSSCs). This study entails the extraction and characterization of natural pigments derived from Chlamydomonas starii and Coelastrella sp. focusing on solvent selection and thermal treatment. Ethanol proved much better than ethyl acetate and had the most remarkable effects on retaining functional groups, especially hydroxyl (O-H) and carbonyl (C=O), which would be important in terms of dye adsorption for improved photon absorption and electron injection. Spectroscopic analyses indicated that the ethanol-extracted dyes, especially non-heated and moderately heated ones, would enable a broad absorption of light within the visible spectrum. These findings hence have demonstrated that natural dyes extracted with ethanol were better than those extracted with ethyl acetate, which makes ethanol more efficient, scalable, and greener solvent for extraction of natural dyes compared to ethyl acetate. Future research is to focus on mixed solvent systems and stabilization techniques to improve dye performance even further. This will therefore be the greatest scion towards high-efficiency DSSCs while further supporting the global transition efforts toward sustainable energy technologies.