Single-Atom-Thick Active Layers Realized in Nanolaminated Ti3(AlxCu1-x)C2 and Its Artificial Enzyme Behavior.

A Ti3(AlxCu1-x)C2 phase with Cu atoms with a degree of ordering in the A plane is synthesized through the A site replacement reaction in CuCl2 molten salt. The weakly bonded single-atom-thick Cu layers in a Ti3(AlxCu1-x)C2 MAX phase provide actives sites for catalysis chemistry. As-synthesized Ti3(AlxCu1-x)C2 presents unusual peroxidase-like catalytic activity similar to that of natural enzymes. A fabricated Ti3(AlxCu1-x)C2/chitosan/glassy carbon electrode biosensor prototype also exhibits a low detection limit in the electrochemical sensing of H2O2. These results have broad implications for property tailoring in a nanolaminated MAX phase by replacing the A site with late transition elements.