A theoretical study has modeled the linear optical and photothermal performance of titanium dioxide and gold core–shell nanocomposites, identifying key structural and environmental trade-offs for solar energy conversion applications. Researchers Shewa Getachew Mamo and Sisay Shewamare evaluated the localized surface plasmon resonance of the TiO2@Au nanostructures across a spectral range extending from 300 to 1100 nanometers. Their investigation was carried out within the quasi-static approximation and implemented the Lorentz–Drude model to accurately represent the dielectric response of the outer gold shell.

The calculations demonstrate that altering structural parameters directly shifts the optical behavior of the nanocomposites across the examined spectrum. Increasing the thickness of the gold shell enhances optical absorption through plasmonic resonance tuning across the target wavelengths. Concurrently, expanding the inner TiO2 core radius produces a pronounced red-shift in resonance, moving the absorption profile toward the near-infrared region.

Thermal analysis reveals that photothermal performance is governed by strict structural constraints rather than continuous scaling. The researchers identified an optimal shell thickness for temperature rise, observing that heat dissipation limits further thermal enhancement once the gold shell surpasses this specific dimension. This balance indicates that shell geometry must be precisely calibrated to balance energy absorption against thermal losses.

The surrounding dielectric medium also exerts a significant influence on the operational trade-offs of the core–shell system. Placing the nanocomposites within a high-refractive-index TiO2 environment drives a greater overall temperature rise but lowers photothermal conversion efficiency because of increased scattering. Conversely, embedding the structures in a low-index silicon dioxide host maintains a high conversion efficiency between approximately 85 percent and 99 percent, accompanied by a comparatively lower thermal output.

Reported in Discover Applied Sciences, these theoretical findings outline specific design principles for configuring plasmonic core–shell architectures. By demonstrating how core radii, shell dimensions, and dielectric surroundings govern absorption tuning and heat dissipation, the modeled results provide parameters for optimizing solar thermal conversion systems and related photonic technologies.

Subject of Research: Theoretical modeling of optical and photothermal properties in TiO2@Au core–shell nanocomposites for solar energy conversion

Article Title: Enhanced optical and photothermal performance of TiO2@Au core–shell nanocomposites for solar energy conversion

Article References: Mamo, S. G., & Shewamare, S. (2026). Enhanced optical and photothermal performance of TiO2@Au core–shell nanocomposites for solar energy conversion. Discover Applied Sciences. https://doi.org/10.1007/s42452-026-09847-9

Image Credits: AI Generated

DOI: 10.1007/s42452-026-09847-9

Keywords: TiO2@Au nanocomposites, core-shell nanostructures, localized surface plasmon resonance, photothermal conversion efficiency, solar energy conversion, Lorentz-Drude model, quasi-static approximation, optical absorption, heat dissipation, dielectric environment, near-infrared red-shift, plasmonic resonance tuning, titanium dioxide core, gold shell, silicon dioxide host, photonic applications