Tandem system of inorganic Z-scheme electron pump-living biofilm for photocatalytic liquid fuel generation

Photocatalytic CO 2 reduction (PCR) to value-added chemicals, particularly formic acid (HCOOH), has emerged as a pivotal strategy for sustainable energy conversion. Nevertheless, the performance of conventional photocatalysts is hindered by inefficient charge separation. To overcome these bottlenecks, we propose a novel hybrid photocatalytic system by integrating a tandem Z-scheme heterojunction of hollow CdS (HCdS)@ZnIn 2 S 4 (ZIS) with electroactive biofilms to form HCdS@ZIS-Biofilms. This design couples the inorganic Z-scheme electron transport interface with the biological membranes, exhibiting excellent selective PCR-to-HCOOH conversion (375 μmol h −1 ) and a high apparent quantum yield (AQY) of 14.8%. First, the Z-scheme heterojunction works as electrons bump for continuous generation of photogenerated electrons for the PCR process. Then, photo-induced electrons can be transferred to the bacterial redox enzyme centers via transmembrane electron carrier proteins, thereby driving the cascade of enzymatic CO 2 reduction. This breakthrough in bio-inorganic interfacial engineering opens avenues for advanced applications in carbon-neutral technologies.