Scientists propose new charge separation strategy in ferroelectric photocatalysts

Ferroelectrics are photocatalytic candidates for solar fuel production. However, the performance of ferroelectric photocatalysts is often moderate and cannot achieve overall water splitting.

Recently, a research team led by Prof. Li Can and Prof. Fan Fengtao from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has proposed a new charge separation strategy to fabricate interfacial charge-collecting nanostructures on positive and negative domains of ferroelectric, which enables water splitting in ferroelectric photocatalysts.

This study was published in Nature Communications on July 22.

The researchers chose the ferroelectric BaTiO₃ single domain crystal and Au nanoparticle as a model system to highlight the charge separation mechanism at Au/BaTiO₃ interface. They observed that photogenerated electrons and holes accumulated efficiently within their thermalization length (around 50 nm) around Au nanoparticles located in the positive and negative domains of a BaTiO₃ single crystal, respectively.

They found that the measured thermalization length was an essential experimental prescription for fabricating high-efficiency photocatalytic and photovoltaic devices on the nanoscale. With this structure design, constructed ferroelectric photocatalysts could perform photocatalytic overall water splitting.

"The fabrication of bipolar charge-collecting structures on ferroelectrics to achieve overall water splitting may set a paradigm for utilizing the energetic photogenerated charges in solar energy conversion," said Prof. Fan.