Single Atom Cu‐Mediated Efficient Z‐Scheme Photocatalytic CO 2 Conversion of TiO 2 Hetero‐Phase Assembly

ABSTRACT Constructing metal single‐atom‐mediated Z‐scheme charge transmission is a promising yet challenging avenue to realize efficient solar photocatalysis. Here, a single‐atom Cu‐bridged TiO 2 hetero‐phase assembly with opened cavities and Z‐scheme charge transmission is fabricated via the illumination‐assisted preparation recipe. When tested for gas–solid photocatalytic CO 2 conversion, our photocatalyst displays an extraordinary activity with CH 4 production rate reaching to 327.19 µmol·g −1 ·h −1 , roughly 15.6 and 122.1 times enhancement than Degussa P25 TiO 2 and TiO 2 (B), and it outperforms those of Cu nanoparticles, Pd single atoms, Pt nanoparticles, Pd nanoparticles, and Au nanoparticles‐loaded counterparts as well as most TiO 2 ‐based composites ever reported. Based on the experimental test and theoretical calculation results, Cu single atoms act as the mediator to enhance interfacial charge transfer, which changes the photo‐carrier transmission pathway from type‐II to Z‐scheme, accounting for the significant promotion of photocatalytic capability. The study results could propel the marked optimization of photocatalytic efficiency by steering Z‐scheme charge transport with a single‐atom mediator.