Construction of Janus particles from single-domain ferroelectric PbTiO3 nanoplates for synergistic photocatalytic H2 evolution and value-added organic transformation

Abstract

Janus particles are widely considered ideal photocatalysts for solar-to-chemical conversions since charge carriers can be directionally separated to opposite sites and back reactions can be suppressed. Nevertheless, there are very few general and reliable synthetic protocols for Janus photocatalysts with versatile constituting materials of different physiochemical properties. Inspired by the spontaneous polarization characteristics of ferroelectric semiconductors, a widely applicable approach to construct a series of Janus photocatalysts was demonstrated via two-step photodeposition of different species on the oppositely polarized facets of single-domain ferroelectric PbTiO₃ nanoplates. A model Janus photocatalyst, PbTiO₃-Pt-CoO_x, with Pt and CoO_x particles selectively deposited on the positively and negatively polarized (001) facets of PbTiO₃, respectively, not only greatly enhanced the directional charge separation to different cocatalysts, but also induced a synergistic bifunctional catalytic system for simultaneous H₂ evolution and benzylamine oxidation to valuable N-benzylidenebenzylamine. This work offers a new strategy to fabricate various Janus catalysts for a wide range of potential applications such as clean fuel production, green synthesis of high-value organic molecules, environmental remediation, etc., especially coupled half-reaction systems.