Enhanced Water Interaction at Dual Cu Sites Within the Defects on a Copper Sulfide Layer

Electrochemical transformations of stable molecules, such as CO2 and water, into fuels and value-added chemicals require efficient catalyst surfaces. Introducing controlled defects at atomic scales can offer promising routes to enhance catalyst performance. In this study, defects with novel dual copper sites (-Cu–Cu-) were found within a copper sulfide (Cu–S) layer supported on Cu(111). Using scanning tunneling microscopy (STM) and density functional theory (DFT), these dual copper sites were found to enhance molecular adsorption strength, specifically for water molecules, compared to intact Cu–S layers or pristine copper surfaces. This discovery highlights the potential of engineered dual-site copper defects to advance electrochemical catalytic materials, particularly for reactions involving water activation.