Developing a Tunable Synthesis Route for Hollow Gold Nanoparticles@Semiconductor Core–Shell Heterostructures with Controllable Localized Surface Plasmon Resonance

In the rapidly evolving field of nanotechnology, metal@semiconductor core–shell heterostructures have garnered significant attention for their unique optical and electronic properties. These structures offer immense potential for enhancing light harvesting and tuning the localized surface plasmon resonance (LSPR). However, the lack of a universal and scalable synthetic method for constructing diverse semiconductor shells remains a major challenge. In this study, we report for the first time a versatile low-temperature two-step method for fabricating hollow gold nanoparticles (HGNs)@semiconductor core–shell heterostructures. By employing mercaptobenzoic acid (MBA) as a linker molecule and polyvinylpyrrolidone (PVP) as a stabilizing agent, this method enables the uniform deposition of various semiconductors, including CuO, Fe₃O₄, CdS, FeS, and Ni(OH)₂. The method exhibits broad material applicability and allows precise control of LSPR by adjusting the semiconductor shell thickness, spanning a spectral range from the visible to the near-infrared (NIR) region. Our work not only demonstrates the modulation of LSPR properties through shell thickness but also provides new insights into the metal–semiconductor interfacial dynamics and plasmonic energy transfer mechanisms. This versatile synthetic platform not only lays the foundation for next-generation photocatalysts and optoelectronic devices in the visible and NIR regions but also broadens its potential applications to other metal@compound core–shell systems across fields, such as optoelectronics, energy, and catalysis.