Solar-Driven Massive Production of Dimerized Imine in Aqueous Phase via an Atomically Engineered Photocatalyst

Abstract

Photocatalytic selective oxidation of organics represents a promising avenue for the sustainable production of value-added chemicals, but suffers from sluggish charge separation and difficult selectivity manipulation. In particular, the Schottky barrier-induced adsorption of expected organic products at reduction sites tends to trigger the hydrogenation side reaction, which is more pronounced in the ideal aqueous environment due to distinct polarity. Here, we report a precise cocatalyst strategy on ZnIn2S4 (ZIS) photocatalyst at the atomic level to eliminate the Schottky barrier between ZIS and cocatalyst, thus achieving exceptional activity (565 μmol h−1) and selectivity (99%) for photocatalytic dimerized imine production in aqueous media, which is five times more effective than ZIS loaded with Pt nanoparticles. The excellent performance is achieved by effectively attenuating the accumulation of photogenerated holes near the Pt sites and then suppressing the unwanted hydrogenation side reaction. We further demonstrate that our system can be directly scaled up to 0.5 m2 for scalable outdoor experiment and achieve solar-driven production of benzylimine with 125 mL yield and 97 wt% purity for two weeks under solar irradiation. This study presents an interfacial atomical design strategy for photocatalysts to efficiently produce high-value imine coupled with H2 under mild and green conditions.