Controlling Available Active Sites of Pt-Loaded TiO₂Nanotube-Imprinted Ti Plates for Efficient Dye-Sensitized Solar Cells

Abstract

The counter electrode (CE) of dye-sensitized solar cells (DSSCs) plays an important role for transferring electrons and catalyzing the I-/I3- reduction. Active surface area of the substrate determines the reduction sites of the deposited catalyst as well as the catalytic ability of the CE. An effective method for enhancing and controlling the active surface area of metal plates is provided in this study. The Ti plates are imprinted by TiO2 nanotubes (TNT) via the technique of anodization along with the ultrasonic vibration process. The available active area of imprinted Ti plates is controlled by varying the anodization voltage to produce TNT imprints with different diameters and depths. A solar-to-electricity conversion efficiency (η) of 9.35% was obtained for the DSSC with a TNT-imprinted Ti plate as the CE substrate, while the cell with an imprint-free Ti plate shows an η of 7.81%. The enhanced η is due to the improved electrocatalytic ability of the CE by using the TNT-imprinted Ti plate as the substrate with higher active surface area.

Substrate Diameter-Dependent Photovoltaic Performance of Flexible Fiber-Type Dye-Sensitized Solar Cells with TiO2 Nanoparticle/TiO2 Nanotube Array Photoanodes

“…The nanotube lengths of 5.67, 10.07, 13.02 and 27.53 µm were, respectively, obtained for the nanotubes anodized using 50, 60, 70 and 80 V. The larger diameter and long tubes were attended for the sample prepared using larger voltage for anodization. This phenomenon is similar to those observed using the Ti foils as the substrate for anodization [25][26][27]. It was also found that the enhancements on the diameter and length of nanotubes increased largely when the anodization voltage of 80 V was applied for synthesizing TNA on the Ti wire.…”

Enhancing the Contact Area of Ti Wire as Photoanode Substrate of Flexible Fiber-Type Dye-Sensitized Solar Cells Using the TiO2 Nanotube Growth and Removal Technique

“…V OC values are similar for all FDSSCs, suggesting the recombination rate is similar for the FDSSC with different substrates for photoanodes. The higher J SC values were obtained for the FDSSC with the TNP/TNT-printed Ti wire photoanodes compared to that for the cell with the TNP/Ti wire photoanode, owing to the TNT imprints on the substrate of the photoanode providing better charge transfer and larger surface area for dye adsorption [22]. The FF values are also higher for the FDSSC with TNP/TNT-printed Ti wire photoanodes, indicating the reduced charge-transfer resistance for these cases with modified substrate for photoanodes.…”

“…The FF values are also higher for the FDSSC with TNP/TNT-printed Ti wire photoanodes, indicating the reduced charge-transfer resistance for these cases with modified substrate for photoanodes. On the other hand, among the FDSSC with TNP/TNT-printed Ti wire photoanodes, the highest J SC of 4.66 mA/cm 2 and η of 2.37% were achieved for the cell with photoanode substrate anodized with 30 V. It is inferred that the smallest diameter for the TNT imprints prepared using 30 V could provide the largest surface area for TNP deposition and more routes for transferring charges [22]. Therefore, the best photovoltaic performance was obtained for the FDSSC with the photoanode prepared using substrate pretreated with the smallest anodization voltage.…”

“…However, extra TiO 2 nanomaterials should be coated on the current collector and, hence, more interfaces could be developed to increase charge-transfer resistance. In our previous work, the current collector was modified using the TiO 2 nanotube (TNT) growth-removal process [22,23]. The TNT can also be used as the dye-adsorbing layer in other works [24,25].…”

Biosorption of Malachite Green, Safranine T and Methylene Blue onto Spent Substrate of Flammulina Velutiper

“…With the rapid development of dye industry and the widely use of dyes, there are about 10 percent to 15 percent of the dyes to be released into the environment, which results in the problem of dye wastewater pollution. The treatment methods of dye wastewater include mainly physical, chemical and biological methods [1][2]. In recent years, the agriculture and food industry waste, such as orange peel, sawdust, rice husk as a biosorbent for the removal of dye wastewater has attracted a lot of attention [3].…”