Mechanistic insights into chemical and photochemical transformations of bismuth vanadate photoanodes
Year: 2016
Type: article
Abstract: Artificial photosynthesis relies on the availability of semiconductors that are chemically stable and can efficiently capture solar energy. Although metal oxide semiconductors have been investigated for their promise to resist oxidative attack, materials in this class can suffer from chemical and photochemical instability. Here we present a methodology for evaluating corrosion mechanisms and apply it to bismuth vanadate, a state-of-the-art photoanode. Analysis of changing morphology and composition under solar water splitting conditions reveals chemical instabilities that are not predicted from thermodynamic considerations of stable solid oxide phases, as represented by the Pourbaix diagram for the system. Computational modelling indicates that photoexcited charge carriers accumulated at the surface destabilize the lattice, and that self-passivation by formation of a chemically stable surface phase is kinetically hindered. Although chemical stability of metal oxides cannot be assumed, insight into corrosion mechanisms aids development of protection strategies and discovery of semiconductors with improved stability.
Source: Nature Communications
DOI: 10.1038/ncomms12012
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Awards: G1079818582, G1143651532, G1286236842, G1286251239, G213222014, G2387988524, G2618837358, G30714459, G3083819904, G419881185, G42916606, G4501827968, G498139845, TAS::89 0321::TAS; NEW- JOINT CENTER FOR ARTIFICIAL PHOTOSYNTHESIS (JCAP), PI NATHAN LEWIS, G650090426, G6652958823, G6900011570, G7354628648, G7879503846, TAS::89 0321::TAS; NEW- JOINT CENTER FOR ARTIFICIAL PHOTOSYNTHESIS (JCAP), PI NATHAN LEWIS, G8432801012, G8730422916, G969889393
OpenAlex ID: W2469717910