TiO2/carbon black slurry preparation
The TiO2 and carbon black (T/CB) slurry was prepared as follows: various amounts of carbon black powder (50, 100, 200, and 500 mg) were mixed with 40-nm sizes of TiO2 nanoparticles in various weight ratios (T/CB; 10:1, 5:1, 2.5:1, and 1:1). The mixture was dispersed by ultrasonication (750 W, Sonics & Materials, Inc, Newtown, CT, USA) for 10 min. After the ultrasonic treatment, 100 μl of Triton X-100 (Sigma-Aldrich) was added to the mixture and further ultrasonic treatment was carried for 10 min. Electrodes and cell fabrication RGFP966 Samples of fluorine-doped tin oxide substrate (Pilkington TEC Glass-TEC 8, Nippon Sheet Glass Co., Ltd, Tokyo, Japan) were washed in a detergent solution, DI water, Smad inhibitor an ethanol-acetone mixture solution (v/v = 1/1), and 2-propanol in an
ultrasonic bath for 5 min, in turn, and selleck chemical then treated by a UV-O3 system for 15 min to introduce a hydrophilic surface. Nanocrystalline TiO2 paste (20 nm, ENB-Korea, Daejeon, Korea) was coated onto the FTO glasses using a doctor blade. The TiO2-coated FTO glasses were annealed at 500°C for 1.5 h to create a TiO2 film; then, the substrate was treated with 40 mM of an aqueous solution of TiCl4 at 80°C for 30 min and rinsed with DI water and an ethanol-acetonitrile mixture solution (v/v = 1/1). The substrate was heat-treated again at 500°C for 30 min and immersed in 0.3 mM (Bu4N)2[Ru(dcbpyH)2(NCS)2] (N719) in a mixed solvent of acetonitrile and tert-butanol (v/v = 1/1) with 0.075 mM DINHOP for 24 h. To prepare counter electrodes, a 10-M H2PtCl6 solution in ethanol
and T/CB slurry of various weight ratios were coated onto a cleaned FTO glass separately, followed by annealing at 500°C for 1 h in a tube furnace. The working electrode and the counter electrode were sandwiched together using a 50-μm thick Surlyn (DuPont) at 100°C for 10 s. An electrolyte containing a mixture of 0.6 M Liothyronine Sodium 1-hexyl-2,3-dimethyl-imidazolium iodide, 0.1 M guanidine thiocyanate, 0.03 M iodine, and 0.5 M 4-tert-butylpyridine in acetonitrile was injected, and final sealing completed the fabrication of the cell. Results and discussion Figure 1 shows surface morphologies of the pure carbon black and the synthesized TiO2 nanoparticles. The sizes of carbon black and TiO2 particles are 75 and 40 nm, respectively. The carbon black has a lot of active sites for catalysis at edges with high porosity at approximately 75-nm size, and TiO2 can easily be attached onto the FTO substrate at 40-nm size. We applied the mixture of both nanoparticles as a counter electrode; pores for electron transfer with high surface area and good adhesion of catalytic materials can easily be made. Figure 1 FE-SEM image of the (a) carbon black powder and (b) hydrothermally synthesized TiO 2 nanoparticles. Figure 2 shows a thermogravimetric analysis (TGA) of carbon black under air and argon atmosphere.