Polyoxometalate-Mediated Spatially Compartmentalized S-scheme Heterojunction Coupled with Molecular Junction for Overall CO 2 Photoreduction

Rational design of photocatalytic systems coupling the reduction of CO2 with water oxidation is vital for carbon-neutral technologies. Herein, we propose a strategy based on the synergistic assembly of polyoxometalates (POMs) within and on a porphyrinic metal–organic framework (MOF, PCN-222). Cross-scale integration of an S-scheme heterojunction and a molecular junction within a single POM@MOF-POM-TiO2 (TiO2@Ni4PCN-222) system is demonstrated. In this spatially compartmentalized platform, Ni4(H2