Single cobalt atom anchored on carbon nitride with well-defined active sites for photo-enzyme catalysis

By analogy to mono-nuclear metalloenzymes, single-atom dispersed catalysts (SACs) demonstrate very promising performance for many conventional heterogeneous and homogeneous reactions. However, the prospect of integrating SACs with enzymatic catalysis is still unexplored. Herein, atomically dispersed Co sites on ultrathin two-dimensional (2D) carbon nitride nanosheets (Co-1/C3N4) were constructed and applied for efficiently photochemical cofactor (NADH) regeneration. The NADH regeneration yield reached as high as 99%. Subsequently, the in-situ regenerated-NADH triggered alcohol dehydrogenase for enzymatic reduction of aldehyde where 100% alcohol yield was achieved. Using atomic spectroscopy characterization and theoretical calculation, the genuine active sites of Co-1/C3N4 catalyst in reaction system were revealed in the form of CoN3-Cp* moieties (Cp*, 1,2,3,4,5-pentamethylcyclopentadiene). Such a well-defined atomic catalyst opens a new avenue for the organic transformation application of single-atom catalysts in enzyme catalysis.