Enhancing Visible Light Photocatalysis with Hydrogenated Titanium Dioxide for Anti-Fouling Applications
- PDF / 1,495,411 Bytes
- 7 Pages / 432 x 648 pts Page_size
- 67 Downloads / 242 Views
MRS Advances © 2018 Materials Research Society DOI: 10.1557/adv.2018.522
Enhancing Visible Light Photocatalysis with Hydrogenated Titanium Dioxide for Anti-Fouling Applications Safa Al Zaim1, Aikifa Raza1, Jin You Lu1, Daniel Choi1, Nicholas X. Fang2, TieJun Zhang1,* 1
Department of Mechanical and Materials Engineering, Masdar Institute, Khalifa University of Science and Technology, P.O. Box 54224, Abu Dhabi, UAE. *Correspondence: [email protected] 2 Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
ABSTRACT Anti-organic fouling performance of titanium dioxide (TiO2) can be enhanced by extending its light absorption and photocatalytic capability from ultra-violet to the visible range through hydrogenation. In this work, we aim at studying the impact of hydrogenation on the performance of both electron beamdeposited TiO2 thin films and hydrothermally grown TiO2 nanostructures on titanium substrates. Hydrogenation of these TiO2-deposited titanium substrates (TiO2/Ti) are achieved in relatively lowtemperature low-pressure chemical vapor deposition chamber without any noble diatomic hydrogen dissociation catalyst, such as platinum. Our study shows that these hydrogenated TiO2/Ti have better light absorption ability and the titanium substrate itself serves as the active catalyst for hydrogen dissociation and diffusion. By applying hydrogenation to the TiO2 nanostructures, we can enhance photocatalytic performance by 50% through methylene blue degradation experiments. We have also evaluated the effect of hydrogenation on carrier density and mobility in TiO2/Ti. We recommend the hydrogenation of hydrothermally grown TiO2 nanostructure on titanium substrates for scalable photocatalytic applications.
INTRODUCTION Titanium dioxide (TiO2) is a highly stable, affordable material with large corrosion resistance. It is attractive to many solar applications, but its band gap of 3.4 eV does not meet the 1.4 eV required for visible light photocatalysis [1]. It has been found that hydrogenation of TiO2 can alter its optical properties to match the solar spectrum, which is critical to any photocatalytic, photovoltaic, and even solar thermal applications [2-4]. Impurities or dopants can produce additional energy bands in the band structure of TiO2 because of their interactions with the electrons of the host. When these bands are close to the valence or conduction band of TiO2, the band gap is reduced. However, an excessive amount of dopant can distort the lattice, breaking bonds and producing defects, so the fabrication conditions must be evaluated to produce the optimized concentration of dopants. Similarly, the characteristics of the host lattice as well as the experimental conditions affects the diffusion mechanism of the dopant inside the materials [5]. In the
Downloaded from https://www.cambridge.org/core. University of Arizona, on 26 Jul 2018 at 19:16:48, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10
Data Loading...
