Engineering the Au-Cu 2 O Crystalline Interfaces for Structural and Catalytic Integration.

Precise structural control has attracted tremendous interest in pursuit of the tailoring of physical properties. Here, this work shows that through strong ligand-mediated interfacial energy control, Au-Cu 2 O dumbbell structures where both the Au nanorod (AuNR) and the partially encapsulating Cu 2 O domains are highly crystalline. The synthetic advance allows physical separation of the Au and Cu 2 O domains, in addition to the use of long nanorods with tunable absorption wavelength, and the crystalline Cu 2 O domain with well-defined facets. The interplay of plasmon and Schottky effects boosts the photocatalytic performance in the model photodegradation of methyl orange, showing superior catalytic efficiency than the AuNR@Cu 2 O core-shell structures. In addition, compared to the typical core-shell structures, the AuNR-Cu 2 O dumbbells can effectively electrochemically catalyze the CO 2 to C 2+ products (ethanol and ethylene) via a cascade reaction pathway. The excellent dual function of both photo- and electrocatalysis can be attributed to the fine physical separation of the crystalline Au and Cu 2 O domains.