Fabrication of Titanium Dioxide Nanotube Array as a Photocathode for Hydrogen Evolution

Abstract

In this study, we present an effective method to fabricate TiO 2 -based photocathode for hydrogen production. The Pt/TiO 2 composites were synthesized by using TiO 2 nanotube arrays (TNTAs) as a support. The TNTAs were electrochemically fabricated using 20 × 18 mm 2 titanium foils as the anode. Pt ions were loaded onto the TNTAs to form Pt/TiO 2 nanocomposites for the enhancement of photoelectron-chemical performance of water splitting. The highly oriented and ordered TNTAs at about 100 nm in diameter and 17 μm in length was obtained after 8 h of anodization. The TEM images showed that Pt nanoparticles were well-dispersed on the surface of TNTAs with diameters of 1.5-5 nm. In addition, TiO 2 and Pt/TiO 2 nanotube arrays were used for photoelectrochemical water splitting in 0.5 M Na 2 SO 4 electrolyte under UV light irradiation at 10 mW/cm 2 . The photocurrent density at a overpotential of -0.65 V vs. Ag/AgCl (-0.1 V vs. RHE) by Pt/TiO 2 composite was higher than the pure TiO 2 nanotube arrays electrode. In addition, the overpotential of TNTAs in the presence of UV light was 0.1 V lower but and the hydrogen production was 1.3 times higher than that in dark. The hydrogen generation by TNTAs and Pt/TNTAs at -0.85V vs. Ag/AgCl under UV light irradiation was 1.9 and 15.5 times higher than that in dark.