Evaluation of Dye Loading on Photoanodes of Dye-Sensitized Solar Cells Utilizing a Mixture of TiO₂ and Magnesium/Aluminum Layered Double Hydroxide (LDH)

This research focused on developing photoanodes for dye-sensitized solar cells (DSSCs) by combining titanium dioxide (TiO₂), layered double hydroxide (LDH), and TiO₂-LDH composites. DSSCs were fabricated using different photoanode materials, including TiO₂, LDH, and various TiO₂-LDH ratios sensitized with N719 dye and employing an iodide/triiodide redox couple electrolyte. Under simulated sunlight, TiO₂-based DSSCs achieved an impressive 4.57% energy conversion efficiency, while LDH-based devices only reached 0.62%. DSSCs with varying TiO₂-LDH ratios demonstrated efficiencies of 2.4%, 3.2%, and 3.3% for 1:1, 1:3, and 1:5 ratios, respectively. The superior performance of TiO₂-based DSSCs was attributed to higher electron transfer efficiency. Dye loading analysis revealed that TiO₂ had the highest dye loading due to its extensive surface area, while LDH had the lowest loading. Adsorption kinetics of N719 dye on TiO₂ and LDH films indicated a pseudo-second-order model, suggesting chemical interactions between dye molecules and surface sites.