Engineering the Au‐Cu2O Crystalline Interfaces for Structural and Catalytic Integration

Abstract 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.