Highly efficient photoenzymatic CO₂ reduction dominated by 2D/2D MXene/C₃N₅ heterostructured artificial...

Photoenzyme-coupled catalytic systems offer a promising avenue for selectively converting CO₂ into high-value chemicals or fuels. However, two key challenges currently hinder their widespread application: the heavy reliance on the costly coenzyme NADH, and the necessity for metal-electron mediators or photosensitizers to address sluggish reaction kinetics. Herein, we present a robust 2D/2D MXene/C₃N₅ heterostructured artificial photosynthesis platform for in situ NADH regeneration and photoenzyme synergistic CO₂ conversion to HCOOH. The efficiencies of utilizing and transmitting photogenerated charges are significantly enhanced by the abundant π-π conjugation electrons and well-engineered 2D/2D hetero-interfaces. Noteworthy is the achievement of nearly 100 % NADH regeneration efficiency within just 2.5 h by 5 % Ti₃C₂/C₃N₅ without electron mediators, and an impressive HCOOH production rate of 3.51 mmol g^-1h^-1 with nearly 100 % selectivity. This study represents a significant advancement in attaining the highest NADH yield without electron mediator and provides valuable insights into the development of superior 2D/2D heterojunctions for CO₂ conversion.