Effect of gold solution concentration on the formation and photoelectrochemical properties of gold deposited titanium dioxide nanotubes

• Main Authors: Ayal, A.K (Author), Binti Ismail, S.S (Author), Chin, L.Y (Author), Zain, Z.M (Author)
• Format: Article
• Language: English
• Published: Malaysian Society of Analytical Sciences 2018
• Subjects: Gold nanoparticles; Photoelectrochemical properties; Pulse electrodeposition; Titanium dioxide nanotube
• Online Access: View Fulltext in Publisher; View in Scopus
• ISBN: 13942506 (ISSN)
• DOI: 10.17576/mjas-2018-2205-02

Solar photoelectrochemical (PEC) water splitting for hydrogen production is a clean, eco-friendly, and cost-effective technology that uses solar light as the energy source. Metal oxides, such as TiO2, are preferable as a photoanode in PEC water splitting as they have relatively high reactivity, stable in aqueous solution, and cheaper than non-oxide semiconductors. However, TiO2 has a large band gap (3.2 eV) that only allows it to be active upon irradiation with UV light. Thus, gold nanoparticles were deposited onto TiO2 nanotubes (TNT) in this study to extend their spectral response to the visible region. Gold deposited titanium dioxide nanotubes (AuTNT) were synthesized by using pulse electrodeposition. Electrodeposition was carried out in 0.5 M H2SO4 that contained different concentrations (50, 100, 500, and 1,000 µM) of gold solution, with 75% duty cycle and an applied potential of-0.4 V for 20 minutes in a three-electrode electrochemical cell. The TNTs were annealed at 500 °C for 2 hours to induce crystallinity prior to gold deposition. The physicochemical properties of the AuTNT were characterised using a Field Emission Scanning Electron Microscope (FESEM), an Energy Dispersive X-ray (EDX), and an X-ray Diffractometer (XRD). Photoelectrochemical properties of AuTNT electrode was evaluated in 0.5 M Na2SO4 and 2 M C2H5OH under the illumination of a halogen lamp. The AuTNT electrode prepared with 500 µM gold solution demonstrated the highest photocurrent compared to other concentrations of gold. © 2018, Malaysian Society of Analytical Sciences. All rights reserved.