Study of Optical and Electrochemical Properties of Solvent-Dependent Natural Dye Extracted from <i>Rivina humilis</i> L

Abstract

This work aimed to study the natural dye extracted from Indonesian wild plants (Rivina humilis L.) using different solvents. The natural dye was extracted using the maceration method. Three different solvents, namely, aquades, acetone, and ethanol 96%, were used to extract natural dye from Rivina humilis L fruit. The absorbance spectra of the extracted dye were recorded using Ultraviolet-Visible (UV-Vis) spectroscopy. The different spectra of betalain pigment revealed the dye extract's dependence on the solvent. The functional groups of the extracted dye were analyzed using Fourier transform infrared (FTIR) spectroscopy. The adherence of carbonyl and hydroxyl groups from FTIR spectra indicated that this dye could anchor to a semiconducting material, e.g., TiO 2, which was commonly used in dye-sensitized solar cells (DSSC). The electrochemical properties of the extracted pigments were studied through higher occupied molecular orbital (HOMO) and lower unoccupied molecular orbital (LUMO) energy levels. Based on the results, the best performance to construct DSSC was achieved by natural dye adsorption with aquades solvent.