Aerosol-assisted chemical vapour deposition of highly efficient mixed anatase-rutile TiO2 for photoelectrochemical water splitting

Abstract

Aerosol-assisted chemical vapour deposition (AACVD) has been used in conjunction with new and bespoke precursors for the fabrication of highly nanostructured, mixed anatase-rutile phase TiO2. Precursor syntheses were carried out in two steps, reacting tetrakis(dimethylamino)titanium with a triethanolamine-based ligand complex, followed by reaction with the relevant dry solvent. Suitability for AACVD was assessed by thermogravimetric analysis, and the resulting TiO2 films were characterised by SEM, EDX, Raman, and PXRD, which was used to find relative ratios of anatase and rutile phase in the mixed-system, and respective grain sizes. The resulting TiO2 films show exceptional OH− oxidation performance under simulated solar irradiation, yielding photocurrent densities of 1.06 mA cm−2 at 1.23 V vs. RHE, and a peak incident photon conversion efficiency of 95.6% at 380 nm incident light, indicating their promise for use in photoanodes for water splitting application.