Altering the Electrocatalytic Activity of Plasmonic Cu/Cu 2 O Nanocomposites towards Water Splitting through Surface Functionalization with Various Amino Acids

Abstract Present study explores stabilization of copper/cuprous oxide nanomaterials using amino acids as capping agents. The one‐pot and time efficient synthesis method have been employed to synthesize amino acids functionalized copper nanomaterials. The nanomaterials are composed of both copper (0) and copper (I) species and are stable towards environmental oxidation under ambient conditions. Eight different amino acids were used for surface functionalization of the Cu/Cu 2 O nanocomposites where the type of amino acids are found to play an important role in manipulating the morphology, crystalline nature and the optical properties of the synthesized nanocomposites. Moreover, these materials are tested for electrochemical water splitting process and are found superior to traditional Cu‐based electro‐catalysts reported in literature. The capping with amino acids lead to modification in the electro‐chemical parameters such as charge carrier density, flat band potential, electrochemical surface area, etc. activity dependent on amino acid used. Among these amino acids, Alanine capped nanocomposites gave highest current density of 125±5 mA cm −2 at an over potential of −0.4 V vs. RHE.