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.