(Digital Presentation) Synthesis and Characterization of TiO2 Nanotubes for Solar Cell Applications Using an Anodizing Procedure

Abstract

As the photoanode material, TiO2 is the backbone of cost-effective dye-sensitized solar cells. Herein, we propose a green, low-cost, and environmentally friendly synthesis method for titanium dioxide nanotubes using the anodizing process. The anodizing process was carried out in a chemical cell, and the effect of voltage and anodizing time on the creation of pure titanium dioxide nanotubes was investigated. A grade 4 titanium sheet with a thickness of 1 mm was utilized to make titanium oxide nanotubes. First, the titanium sheet was sliced into 1.5 × 1.5 cm squares, and the samples were sanded and polished with SiC sanding sheets ranging in grade from 180 to 3000. After that, the samples were immersed in an ultrasonic bath for 15 minutes to degrease and remove surface impurities in an equal amount of acetone-ethanol solution. A two-electrode cell was utilized for anodizing, with a graphite electrode as the cathode, a titanium sample as the anode, and an electrolyte solution containing 0.5 percent by weight of HF acid and 1:7 acetic acid with a pH of 3.5. The anode and cathode were separated by four centimeters. Different voltages and times were applied and studied in this experiment. Anodization was performed on samples produced at 20 and 15 volts for 15 and 30 minutes, respectively. The crystallization of titanium dioxide nanotubes, as well as their strength and stickiness, were caused by annealing these layers. The electrical characteristics, microstructure, and phases generated before and after heat treatment were investigated using XRD, FESEM, and FPP tests. The titanium dioxide nanotubes were then stacked using the DC sputtering method to increase their structural, crystallographic, and electrical properties for application in solar cells at three different distances of 3, 4, and 5 cm.