Microwave‐Assisted Synthesis of Ultrastable Cu@TiO₂ Core‐Shell Nanowires with Tunable Diameters via a Redox‐Hydrolysis Synergetic Process

Abstract The nanoscale integration of copper metal, frequently with semiconductor heterostructure interfaces, is a promising route for fabricating new micro‐/nanoelectronic devices. Synthesizing such systems using wet‐chemistry methods requires stabilization of nano‐Cu against corrosion/oxidation, which has proven to be challenging. Here we report a methodology for the facile preparation of Cu@TiO₂ core‐shell nanowires (NWs). The synthesis combines redox formation of Cu NWs with kinetically controlled hydrolysis of a titania precursor in a single‐pot microwave reaction. The final core‐shell NWs can be precisely tailored with 20‐nm to 140‐nm Cu core diameters, aspect ratios >250, and a 10‐nm porous titania shell. This metal/semiconductor heterojunction is particularly important for its excellent photocatalytic activity. The rapid microwave‐assisted synthesis provides a potentially generalizable paradigm for the rational design of heterogeneous nanostructures with metals and oxides.