Evaluation of Various Combination Ratios of Polymer-Based Dyes from Mangosteen Pericarp and Ti Plant for Grätzel Cell Efficiency Using Response Surface Methodology

This study investigates the performance of combining polymer-rich natural dyes from Mangosteen pericarp and Ti plant leaves as sensitizers for Grätzel cells. The mangosteen pericarp is rich in natural polymers, including polyphenols, anthocyanins, and polysaccharides. These compounds enhance light absorption, electron transfer, film formation, and dye adhesion on the TiO ₂ surface. The Ti plant leaves contain a high amount of chlorophyll. These compounds are well-known for their ability to capture light and act as photosensitizers, especially for Grätzel cells. Using Response Surface Methodology (RSM) with a Box-Behnken Design, the research evaluates the effects of dye combination ratios, dye soaking time (DST), and light soaking time (LST) on Grätzel cell efficiency. UV-Vis spectrophotometry was employed to analyze the light absorption characteristics of the natural dyes, revealing that a 2:8 ratio (20% Mangosteen pericarp dye and 80% Ti plant dye) exhibited the highest peak absorbance of 0.4685 at 665.452 nm. Grätzel cells with this 2:8 ratio achieved the highest average efficiency of 0.1989% under optimal conditions of 48 hours DST and 2.55 hours LST. While extended DST improved efficiency, longer LST and a higher proportion of Ti plant dye negatively impacted stability and performance. Statistical analysis indicated significant interactions among the parameters, with varying efficiency based on the dye composition and soaking durations.