Light-Driven Sustainable Heck Coupling Using Copper Oxide-Pd Nanohybrid-Based Mie Resonators

Photocatalysis offers a sustainable route for chemical transformations by harnessing solar light rather than relying on fossil–fuel-based heating. We have designed and synthesized nanoscale-engineered cuprous oxide and cupric oxide nanoparticles, each decorated with a thin palladium layer (Cu 2 O–Pd and CuO–Pd), to form hybrid nanostructures, creating well-defined interfaces that exploit enhanced optical properties, particularly dielectric Mie resonances and interfacial charge transfer, to drive light-assisted Heck carbon–carbon (C–C) coupling. Cu 2 O–Pd and CuO–Pd nanocatalysts achieved complete conversion to trans -stilbene within 2 h under simulated solar illumination intensity of ∼111 mW/cm 2 in a N,N-dimethylformamide (DMF)/H 2 O solvent mixture (v/v = 80:20), whereas pristine oxides were nearly inactive. Spectroscopic, microscopic, and finite-difference time-domain (FDTD) simulation analyses confirmed that nanoscale hybrid interfaces promote resonant light confinement and efficient hot-carrier generation, thereby enhancing photocatalytic activity. Notably, Cu 2 O–Pd exhibited an ∼1.56× rate enhancement under illumination compared to purely thermal conditions. These findings emphasize the distinctive nanoscale interfacial synergy at Cu 2 O–Pd interfaces and provide a rational design strategy for green cross-coupling catalysis under solar irradiation, particularly relevant to sustainable synthesis of fine chemicals and pharmaceuticals, as well as other solar-to-chemical energy conversion processes.