Mn₅Si₃@SiO₂ Nanowires as Reusable High-Temperature Photothermal Nanoheaters

High-performance photothermal conversion materials are important to light-operated heating, detection, and imaging. Except for the requirement of high efficiency, availability in severe conditions stands as another essential for extensive applications. Herein, with Mn5Si3 cores as the heating medium and dielectric SiO2 shells to optimize energy utilization (promoting light absorption and reducing heat loss), Mn5Si3@SiO2 nanowires output a photothermal conversion efficiency of ∼60.12% that can work stably at a temperature of >460 °C (980 nm laser excitation). Microscopic thermal imaging reveals a well-controllable power-temperature dependence with rapid response (<100 ms). A coil of Mn5Si3@SiO2 nanowires succeeds in igniting sucrose crystals, melting metal tin in an air environment, and achieving a laser-driven large-scale hydrothermal synthesis of self-assembled ZnO nanorods. These experiments confirm the availability of a complex physical and chemical environment for micro- and macroscale photothermal applications.