Porous nanoparticles are very popular because of their high surface/volume ratio; moreover, they have stronger plasmonic properties than their solid counterparts. Due to these properties, these are potential candidates in optical, or even in ophthalmological applications. We prepared porous gold nanoparticles on SiO 2 / Si as well as on sapphire substrates with solid-state dewetting–dealloying methods. In this work, we studied the morphological and optical properties of porous gold nanoparticles coated with a thin ( ∼ 7 nm) TiO 2 layer using the plasma-enhanced atomic layer deposition method. We show that heat treatments can be used to tune the optical properties of titania coated porous gold hybrid nanoparticles in a wide range of wavelengths. The change in the optical properties is induced by the TiO 2 phase transformation, which also initiates a change in the local refractive index, and assisted by the decrease of the melting point of Au on the nanoscale.

中文翻译：

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二氧化钛涂层多孔金纳米粒子的光学性质的形态学和原位局部折射率变化引起的调谐

多孔纳米粒子因其高表面积/体积比而非常受欢迎；此外，它们比固体对应物具有更强的等离子体特性。由于这些特性，它们是光学甚至眼科应用中的潜在候选者。我们使用固态去湿-脱合金方法在 SiO 2 / Si 以及蓝宝石衬底上制备了多孔金纳米粒子。在这项工作中，我们使用等离子体增强原子层沉积方法研究了涂覆有薄（~7 nm）TiO 2 层的多孔金纳米粒子的形态和光学特性。我们表明热处理可用于在很宽的波长范围内调节二氧化钛涂层多孔金杂化纳米粒子的光学特性。光学性质的变化是由 TiO 2 相变引起的，