Novel bipolar charge collecting structure enabling overall water splitting on ferroelectric photocatalysts

Abstract Due to the unidirectional charge separation and above-gap photovoltage, ferroelectrics have been considered as excellent photocatalytic candidates for solar fuel production. However, the performance of ferroelectric photocatalysts is often moderate. Few reports demonstrated that these kinds of photocatalyst could achieve overall water splitting. Here we propose a novel approach to fabricate interfacial charge collecting nano-structures on ferroelectric’s positive and negative domains, enabling overall water splitting in ferroelectric photocatalysts. We observed efficient accumulations of photogenerated electrons and holes within their thermalization length (about 50 nm) around the Au nanoparticles located in the positive and negative domains of BaTiO3 single crystal. Photocatalytic overall water splitting was firstly observed on ferroelectric BaTiO3 single crystal after assembly oxidation and reduction cocatalysts on the positive and negative charged Au nanoparticles. The idea of fabricating bipolar charge collecting structure on the ferroelectrics to achieve overall water splitting paves the new way for utilizing the energetic photogenerated charges in solar energy conversion.