Large-scale preparation of nanoporous TiO2 film on titanium substrate with improved photoelectrochemical performance.

Beihui Tan,Mingce Long,Yue Zhang

doi:10.1186/1556-276x-9-190

Abstract

Fabrication of three-dimensional TiO2 films on Ti substrates is one important strategy to obtain efficient electrodes for energy conversion and environmental applications. In this work, we found that hierarchical porous TiO2 film can be prepared by treating H2O2 pre-oxidized Ti substrate in TiCl3 solution followed by calcinations. The formation process is a combination of the corrosion of Ti substrate and the oxidation hydrolysis of TiCl3. According to the characterizations by scanning electron microscopy (SEM), X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS), the anatase phase TiO2 films show porous morphology with the smallest diameter of 20 nm and possess enhanced optical absorption properties. Using the porous film as a working electrode, we found that it displays efficient activity for photoelectrocatalytic decolorization of rhodamine B (RhB) and photocurrent generation, with a photocurrent density as high as 1.2 mA/cm2. It represents a potential method to fabricate large-area nanoporous TiO2 film on Ti substrate due to the scalability of such chemical oxidation process.

Highlights

In recent years, TiO2 has been widely studied and applied in diverse fields, such as photocatalysis, dyesensitized solar cell, self-cleaning surface, sensor, and biomedicine [1,2,3,4,5,6]
Titanium suffers from corrosion in the hot HCl solution, and the corrosion rate depends on the temperature and the concentration of acid
The TiOH2+ and Ti(IV) polymer generated by the hydrolysis of TiCl3 would precipitate and deposit over the surface (Equations 1 and 2) so as to retard the corrosion of Ti plate and avoid the completed dissolution of Ti plate [17,19]

Summary

Introduction

TiO2 has been widely studied and applied in diverse fields, such as photocatalysis, dyesensitized solar cell, self-cleaning surface, sensor, and biomedicine [1,2,3,4,5,6]. Fabricating nanostructral TiO2 films over metallic Ti substrates is a promising way to providing high-performance photoresponsible electrodes for photoelectrochemical applications. The general method to prepare nanoporous TiO2 film on Ti substrate is through anodic oxidation and post-sonication [10,12]. In this contribution, we proposed a facile way to fabricate nanoporous TiO2 films by post-treating the H2O2-oxidized TiO2 film in a TiCl3 solution. The as-prepared nanoporous TiO2 film display homogeneous porous structure with enhanced optical adsorption property and photoelectrocatalytic performance, which indicates that the film is promising in the applications of water purification and photoelectrochemical devices

Methods

Results

Conclusion