Optimized Self‐Templating Synthesis Method for Highly Crystalline Hollow Cu2O Nanoboxes

Abstract Hollow nanomaterials consisting of non‐noble metal oxides have wide applications in catalysis, and many preparation methods for this kind of structures are established. However, it is still challenging to fabricate non‐noble‐metal hollow structures featuring high crystallinity, regular polyhedral morphologies, and small sizes, owing to their relatively low chemical stability and the stringent hollowing conditions. Here in this work, an optimized self‐templating synthesis method with refined control over the heating program and solution environment, which can alleviate the common issues of morphology and crystallinity degradation from precursors during hollowing process, is reported. Through this method, highly crystalline Cu 2 O nanobox with sizes below 50 nm is successfully prepared. Benefiting from the unique hollow structures, the Cu 2 O nanobox/C catalyst gives outstanding performances in catalyzing the oxidative homocoupling of phenylacetylene, with the advantages of lower metal loading, mild reaction conditions, and no additives. This optimized method can be extended to the preparation of other non‐noble‐metal hollow materials with sophisticated architectures.