Fluorine doped tin oxide coated glass slide fto

Fluorine Doped Tin Oxide coated glass slide (FTO, Sigma Aldrich) was coated with the rGO samples by using the electrochemical reduction method. The FTO glasses (2 cm² each) were immersed into a mixture of 100 mL of deionized water (DI) water, 5 mL lemon juice and 0.01 g of GO powder. The lemon juice was extracted from unripe lemon fruit by squeezing out the juice and then sifted with a stainless steel sifter. The lemon juice was tested with a pH meter and showed a pH of approximately 2.3. This process was performed on a set of different voltages; 5, 10, 15, 20, and 25 V for 5 min. The instrument setup was as shown in Figure 2.

Nitric acid, 69% (HNO₃), sodium iodide (NaI), iodine (I₂), propylene carbonate (PC), polyethylene glycol (PEG) with a molecular weight of 10,000, 8000, 6000, 4000, and 2000 gmol⁻¹, 4,4′-diphenylmethane diisocyanate (MDI), 96% ethanol, and iso-propanol (IPA) were purchased from Merck. Titanium dioxide (TiO₂, Aeroxide P25), 4-(1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol (Triton X-100), Di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato) ruthenium (II) (N719), chloroplatinic acid hexahydrate (H₂PtCl₆·6H₂O), and a fluorine-doped tin oxide coated glass slide (FTO) were purchased from Sigma-Aldrich, Melbourne.