Modification Effects of Chenodeoxycholic Acid (CDCA) on the Characterization of Dye Mixtures and Implications for DyeSensitized Solar Cell Performance

This study investigated five characterizations of dye mixture of chlorophyll and anthocyanin extracted from neem leaves and rosella flower respectively using distilled water and ethanol under UV-Vis absorption spectroscopy, Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD) analysis, Energy Dispersive Spectroscopy (EDS), and Scanning Electron Microscopy (SEM). Sample mixture Ne+Hw being the optimized dye and was further treated with chenodeoxycholic acid (CDCA) additive in different molar concentration with 1.0mM having the broadest band and long term stability. The UV spectrophotoscopy for optimized and additive dyes showed the highest absorbance value of 3.5 a.u and 2.5 a.u respectively while the absorption spectra peaked at 550nm, 660nm (optimized) and 550nm (additive). The FTIR showed negative shifts in the main peaks between the optimized dye and the CDCA dye molecules, with more functional groups in additive dye than in optimized dye as a result of the formation of intermolecular bonding. The XRD spectra of optimized and additive dyes solutions showed a negative shift on the diffraction angles from 33.12o to 30.42o respectively. This was attributed to the effect of CDCA causing reduction in the optimized dye concentration upon addition, while sharp and narrow bands were associated with improved crystallinity and reduced grain size in the additive dye. The EDS revealed additional elements of sodium (Na), magnesium (Mg), manganese (Mn) and silver (Ag) on the substrate AA. The SEM showed more compacted structure with reduced pore size on additive dye morphology, and the rough surface of TiO2 substrate upon dye adsorption. These improvements are expected to enhance injection and reduce recombination in DSSCs.