Photoanodes on titanium substrates: one-step deposited BiVO4 versus two-step nano-V2O5 films impregnated with Bi3+

Author(s)

Gromboni, Murilo F. ^[1] ; Araujo, Moises A. ^[1] ; Downey, Elizabeth ^[2] ; Marken, Frank ^[2] ; Mascaro, Lucia H. ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Bath, Dept Chem, Bath BA2 7AY, Avon - England

• Document type: Journal article
• Source: Journal of Solid State Electrochemistry; v. 20, n. 1, p. 273-283, JAN 2016.
• Web of Science Citations: 3

Abstract

One-step deposition of photoelectrochemically active BiVO4 (monoclinic) from a polyethylene glycol (PEG300) precursor paint onto titanium substrates is demonstrated to lead to more complex multioxide phase films. Photocurrents in 0.5 M Na2SO4 remain relatively low when compared to those reported on tin-doped indium oxide (ITO) substrates, possibly due to the effect of detrimental underlying titanium oxide phases or mixed phases. For comparison, the one-step deposition is demonstrated also for the direct formation of V2O5 nanocrystalline films, which also exhibited low photoelectrochemical activity. Impregnation of nanocrystalline V2O5 with aqueous Bi3+ is shown to cause substantial recrystallization with formation of much more photoactive BiVO4. In particular, on low-temperature (high surface area) nano-V2O5 (400 A degrees C) and after further mild annealing at 400 A degrees C much improved photoelectrochemical water oxidation activity (ca. 0.3 mA cm(-2) at 1.0 V vs Ag/AgCl (KCl (3 M) at 0.1-W cm(-2) xenon lamp radiation) is observed. This opens up a new mild temperature two-step route for BiVO4 photocatalysts on practical titanium substrates. (AU)

• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC