Visible Light Absorption and Photo-Sensitizing Characteristics of Natural Dye Extracted from Mangosteen Pericarps Using Different Solvents

Dye is an important factor in determining the efficiency of a dye-sensitized solar cell (DSSC) device. One of the dyes derived from natural resource is anthocyanin. At the same time, one of the natural resources containing anthocyanin is a tropical plant called mangosteen. In this work, the characteristics of anthocyanin extracted from mangosteen pericarps using different solvents have been examined. The anthocyanin was extracted from mangosteen pericarps using various different solvents, i.e. dry ethanol, ethanol containing 1% HCl, and ethanol containing 1% acetic acid. Absorption characteristic of dye extracted from different solvents was determined using ultraviolet-visible spectroscopy (UV-Vis). Fourier transform infrared (FTIR) was used to examine the functional groups of the extracted dye. Visible light absorption and photo-sensitizing characteristics of the extracted natural dye were then investigated through their applications in a DSSC device. The results from infrared characterization showed that all of the extracted dyes indicated the same tendency with the characteristic of anthocyanin. At the same time, the UV-Vis examination revealed that the dye extracted using solvent HCl 1% acidified ethanol was found to have a visible light absorption at a wavelength of 533 nm. This result indicated that HCl 1% acidified ethanol was the best solvent to extract anthocyanin from mangosteen pericarps. The activity of the DSSC device sensitized using the extracted dye through a photocurrent-voltage examination showed a power conversion efficiency of 0.23% and 0.18% for the device using the commercial dye and the mangosteen extracted dye, respectively. This result is quite convincing and promising for the next DSSC device development using natural dye extracted from mangosteen pericarps.