Enhanced photocatalytic CO₂ conversion over 0D/2D AgVO₃/TiO₂ heterojunctions assisted by Z-scheme charge separation

Rationally utilizing Z-scheme charge-regulated mechanisms is an effective strategy to improve photocatalytic CO₂ reduction efficiency. Herein, AgVO₃ quantum dots (QDs) are in-situ anchored on TiO₂ nanosheets (NSs) to construct a 0D/2D AgVO₃/TiO₂ direct Z-scheme heterojunction (DZH). TiO₂ NSs prevent the self-aggregation of AgVO₃ QDs, thereby optimizing the morphological structure of the system. AgVO₃ QDs enhance the optical absorption capacity of the nanohybrids, thus improving the efficiency of sunlight utilization. Meanwhile, matched energy band structures and the suitable internal interfacial electric field (−)AgVO₃/(+)TiO₂ facilitate the construction of a DZH, significantly boosting the separation of photogenerated electron-hole pairs and maintaining the highest redox potential in the system. The optimized AgVO₃/TiO₂ nanohybrid exhibits competitive photocatalytic CO₂ reduction efficiency (47.61 µmol h⁻¹ g⁻¹ for CO), without any cocatalyst, which is 20.97 times higher than pristine TiO₂ NSs. This work presents a rational design for a DZH and guides efficient photocatalytic CO₂ reduction catalyst exploration.