Ferroelectrics hold spontaneous polarization that can be switched by electric field. It may generate a switchable electric field across the solid–liquid interface, which provides a platform to control chemical reactions (physical properties) using physical fields (chemical stimuli). However, it is challenging to in-situ control such polarization-induced interfacial chemical structure and electric field. In this talk, I will introduce how to selectively construct chemical bonds at the surface of ferroelectric BiFeO3 in aqueous solution, leading to a reversible bulk polarization switching, without the application of electric field. We discover that the reversible polarization switching is ascribed to the sufficient formation of polarization-selective chemical bonds at its surface, which decreases the interfacial chemical energy. This water-induced ferroelectric switching allows us to construct large-scale type-printing of polarization  using green energy and opens up new opportunities for sensing , high-efficient catalysis , and Bio-tissue proliferation , etc.
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 Type-printable ferroelectric superdomain for enhanced mid-infrared photodetector, submitted.
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