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Hollow Au−Cu 2 O core−shell nanoparticles were synthesized by using hollow gold nanoparticles (HGNs) as the plasmon-tailorable cores to direct epitaxial growth of Cu 2 O nanoshells. The effective geometry control of hollow Au−Cu 2 O core−shell nanoparticles was achieved through adjusting the HGN core sizes, Cu 2 O shell thicknesses, and morphologies related to structure-directing agents. The morphology-dependent plasmonic band red-shifts across the visible and near-infrared spectral regions were observed from experimental extinction spectra and theoretical simulation based on the finite-difference time-domain method. Moreover, the hollow Au−Cu 2 O core−shell nanoparticles with synergistic optical properties exhibited higher photocatalytic performance in the photodegradation of methyl orange when compared to pristine Cu 2 O and solid Au−Cu 2 O core−shell nanoparticles under visible-light irradiation due to the efficient photoinduced charge separation, which could mainly be attributed to the Schottky barrier and plasmon-induced resonant energy transfer. Such optical tunability achieved through the hollow cores and structure-directed shells is of benefit to the performance optimization of metal−semiconductor nanoparticles for photonic, electronic, and photocatalytic applications.

The development of flexible sensor with high sensitivity and short response time has been given great attention due to their potential applications in medical diagnosis and health monitoring. Herein, we...