Kinetic phases of Ag–Cu alloy films are accessible through photodeposition

Silver and copper are each widely-studied metals for catalyzing the CO2 reduction reaction (CO2RR){,} yet studies of Ag–Cu alloys are very rare due to the immiscibility of the two metals. Reported herein is a synthetic route that provides access to Ag–Cu alloys at ambient pressures and temperatures. This method involves solution-depositing a homogeneous mixture of silver(i) 2-ethylhexanoate and copper(ii) bis-(2-ethylhexanoate) on a substrate{,} and photolyzing the thin films with ultraviolet light in an inert dinitrogen atmosphere. This photodeposition procedure is shown to furnish metastable phases of alloys with ∼10 atomic weight% (at%) copper incorporated into the silver lattice. The CO2RR activity of the alloyed sample shows a preference for forming CH4 rather than CO or HCO2− favored for our pure silver and copper films{,} respectively. These results provide proof that photodeposition can be used to access kinetic phases of alloys that are useful for heterogeneous reaction chemistry.