Ruthenizer 535 bistba

The four ZnO NW photoelectrodes prototypes were sensitized with 0.5 mM of N719 dye (Ruthenizer 535-bisTBA from Solaronix®) in an ethanolic solution (Sigma Aldrich) at 60°C for 2 h. Following sensitization, the samples were extracted from the dye solution and meticulously cleaned with ethanol to remove the dye residues. The elaboration process of ZnO NW photoelectrode architecture is shown in Figure 1, which displays (A) AZO as a seed layer and (B) Au film deposition followed by (C) ZnO NWs growth by VLS and (D) obtention of ZnO NWs with different AR. (E,F) show the sensitization process of ZnO NWs with N719 dye.

The working electrodes were made by screen-printing TiO₂ PST-18NR paste (Solaronix) onto an FTO substrate with a film thickness of 16 μm with no blocking layer and scattering layer. After annealing at 500 °C for 60 min under an air atmosphere, the TiO₂ photoanodes were immersed in N719 dye at a concentration of 0.5 mM for 24 h. Previous work^{4 (link)} was used to guide the manufacture of the N719 dye solution (Solaronix S.A.) and the ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte used in this study. N719 dye was prepared using 0.5 mM ruthenizer 535-bisTBA (solaronix) and 50 ml tert-Butanol (> 99.70%, Sigma Aldrich) in 50 ml acetonitrile (99.8%, LiChrosolv). An ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte was prepared using 0.1 M lithium iodide anhydrous (99.99%, Alfa Aesar), 0.05 M iodine (> 99.8%, Riedel–de Haen), 0.6 M 1-propyl-3-methylimidazolium iodide (> 98%, Sigma-Aldrich), 2.5 mM lithium carbonate (99.99%, Sigma-Aldrich) and 0.5 M tert-butylpyridine (96%, Sigma-Aldrich Corp.) in acetonitrile.
A semi-closed approach was used to assemble the WE and CE with a parafilm as a separator and a drop of ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte for the DSSC asymmetrical cell assembly (Fig. 1). In the case of the CE:CE symmetric cells, two FA CEs with an active area of 0.5 cm² were assembled using a parafilm separator and then filled with the same ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte to perform EIS and Tafel tests on the CE catalysts.