Effect of Using Pitaya Peel as Dye-Sensitizer and Dye Molecules in Electrolyte for Photoelectrochemical Reaction

Natural dye sensitizer in photoelectrochemical shows a great potential in improving the efficiency of metal oxide semiconductor especially Titanium dioxide (TiO₂) due to its prominent in absorbing visible light and also low cost. In this work, the effect of using pitaya peel as natural dye sensitizes to TiO2 has been studied through characterizations analysis and PEC test. The bare TiO₂ thin films were fabricated on Fluorine-doped tin oxide (FTO) glass substrate by doctor blade method meanwhile dye-sensitized TiO₂ thin films prepared by immersion of TiO₂ in the dye extracts. The fabricated thin films were characterized with Scanning Electron Microscopy (SEM), X-ray difractometer (XRD), UV-Vis spectrophotometer and photoelectrochemical analysis. The surface of TiO₂ was porous and uniform meanwhile dye particles could not been observed due to very small size. The energy band gap of dye-sensitized TiO₂ from the UV-Vis spectrum is 2.1 eV which is smaller than bare TiO₂ (3.7 eV). Meanwhile, photoactivities of dye-sensitized TiO₂ has the highest compared to bare TiO₂ photoelectrodes which is 127 Microampere/ cm² in 6.25 % v/ v of pitaya dye in the electrolyte. (author)