Single-Atom-Thick Active Layers Realized in Nanolaminated Ti(AlCu)C and Its Artificial Enzyme Behavior.

A Ti(AlCu)C phase with Cu atoms with a degree of ordering in the A plane is synthesized through the A site replacement reaction in CuCl molten salt. The weakly bonded single-atom-thick Cu layers in a Ti(AlCu)C MAX phase provide actives sites for catalysis chemistry. As-synthesized Ti(AlCu)C presents unusual peroxidase-like catalytic activity similar to that of natural enzymes. A fabricated Ti(AlCu)C/chitosan/glassy carbon electrode biosensor prototype also exhibits a low detection limit in the electrochemical sensing of HO. These results have broad implications for property tailoring in a nanolaminated MAX phase by replacing the A site with late transition elements.