Strong near‐field coupling between small catalytic Pt nanoparticles (NPs) and their dielectric supports can be achieved while visible light absorption in the Pt NPs is greatly enhanced via rationally designing the dielectric–Pt core–satellite configuration. Herein, it is demonstrated that the absorption enhancement is mediated by the Mie resonances of the support and the absorption peaks are induced by the magnetic Mie resonances. Utilizing both multipole decomposition analysis and numerical near‐field mapping, resonances including magnetic dipole, magnetic quadrupole, and higher modes are verified. For the generation of strong Mie resonances, a dielectric support with a high refractive index, like TiO₂, can be used not only as the core directly, but also as a shell coated beneath or above the Pt NP layer. Additionally, the redshifts between the absorption peaks contributed by the Pt NPs and the scattering peaks contributed by the dielectric core are ascribed to the intrinsical spectral deviation between near‐ and far‐field optical properties. These findings benefit significantly both the fundamental understanding and optimized design of dielectric supported Pt photocatalysts, providing new opportunities for solar energy conversion and visible light photocatalysis using nonplasmonic catalytic transition metals.

中文翻译：

---

介电支撑的小Pt纳米颗粒中Mie共振增强的可见光吸收对光催化的作用

可以通过合理设计介电-Pt核-卫星构型大大提高Pt NPs中的可见光吸收，同时实现小催化Pt纳米颗粒（NPs）及其介电载体之间的强近场耦合。在本文中，证明了吸收增强是通过载体的Mie共振来介导的，并且吸收峰是通过磁性Mie共振来诱导的。利用多极分解分析和数值近场映射，可以验证包括磁偶极子，磁四极子和更高模式的共振。为了产生强米氏共振，需要使用高折射率的电介质载体，例如TiO ₂不仅可以直接用作核，还可以用作在Pt NP层下方或上方涂覆的外壳。此外，Pt NPs吸收峰与电介质芯散射峰之间的红移归因于近场和远场光学特性之间的固有光谱偏差。这些发现极大地有益于介电负载的Pt光催化剂的基本理解和优化设计，为使用非等离子催化过渡金属的太阳能转化和可见光光催化提供了新的机会。