Fabrication of robust TiO2 thin films by atomized spray pyrolysis deposition for photoelectrochemical water oxidation

Chandana Sampath Kumara Ranasinghe, Junie Jhon M. Vequizo, Akira Yamakata

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

Photoelectrodes are highly essential for the photoelectrochemical water splitting process and development of novel fabrication techniques is vital for further enhancement of activity. In this study, we successfully fabricated highly active TiO2 thin films by using novel atomized spray pyrolysis deposition (ASPD) technique. The ASPD technique utilizes a unique atomization process to produce highly fine aerosols which resulted in a highly crystalline TiO2 nanostructure. The deposition process was optimized by controlling deposition temperatures and precursor amounts. XRD and SEM studies confirmed the formation of anatase TiO2 phase and a highly interconnected nano-flakes on FTO substrate at 550 °C. The photoelectrochemical activity of the optimized thin films showed a photocurrent density of ∼5 mA cm−2 at 1.0 V (vs. Ag/AgCl) in 0.1 M Na2SO4 (aq) under 375 nm (150 mW cm−2) illumination. This photocurrent was much higher than the two other anatases TiO2 thin films fabricated by conventional spray pyrolysis deposition (SPD) using the same precursor and anatase TiO2 powder (particle size ∼21 nm). Transient IR absorption study revealed that the SPD powder based thin films have deeply trapped electrons, whereas ASPD thin films consisted with only free and/or shallowly trapped electrons. Higher crystallinity and enhanced electron conductivity of the TiO2 thin films fabricated by ASPD are responsible for this stable and high photoelectrochemical activity.

Original languageEnglish
Pages (from-to)320-326
Number of pages7
JournalJournal of Photochemistry and Photobiology A: Chemistry
Volume358
DOIs
Publication statusPublished - May 1 2018
Externally publishedYes

Keywords

  • Atomized spray pyrolysis deposition
  • Charge-trapping at the boundaries
  • Photoelectrochemical water splitting
  • Time-resolved IR absorption spectroscopy
  • TiO thin film

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Physics and Astronomy(all)

Fingerprint

Dive into the research topics of 'Fabrication of robust TiO2 thin films by atomized spray pyrolysis deposition for photoelectrochemical water oxidation'. Together they form a unique fingerprint.

Cite this