Mo-O-Bi Bonds as interfacial electron transport bridges to fuel CO2 photoreduction via in-situ reconstruction of black Bi2MoO6/BiO2-x heterojunction

Abstract High photogenerated carrier separation efficiency plays a crucial role in determining the rate of photocatalytic CO2 reduction, but the directional transfer of carrier remains challenging. Here, improved CO2 photoreduction rate and enhanced stability were realized by in-situ construction of BiO2-x nanoparticles on Bi2MoO6 nanoflowers using H2/Ar low temperature plasma. As evidenced by DFT calculations and photocurrent measurements, the Mo-O-Bi bonds between the Bi2MoO6 and BiO2-x interfaces act as a charge transport bridge, facilitating the directional transport of electrons and thus enhancing the rate of photocatalytic reduction reactions involving multiple electrons. Compared with pristine Bi2MoO6, Bi2MoO6/BiO2-x heterojunction has excellent photostability (12 h) and efficient photocatalytic activity (≈ 3.0 times). This indicates that the charge transfer bridge can effectively inhibit the charge recombination and deactivation of pristine Bi2MoO6. This interatomic charge transfer bridges mode can not only solve the stability problem of bismuth-based materials, but also help to design more photocatalytic systems for efficient reduction of CO2.