Plasmonic Copper‐Ruthenium Superstructure for Efficient Photothermal Conversion and Plastic Recycling

Abstract Plasmonic superstructures offer broad prospects in photothermal catalysis, yet their controllable synthesis remains a challenge. Here, a controlled synthesis method for Cu‐Ru plasmonic superstructures via a one‐step polyol reduction process is presented, where Cu nanoparticles serve as the core, while the shell is formed from Ru nanoclusters. Through a comprehensive investigation of the growth mechanism, precise control over the composition and size of the superstructures is achieved. Finite‐difference time‐domain simulations and photothermal conversion experiments demonstrated that the optimized Cu ₃ Ru ₁ superstructures possess strong light absorption capabilities and efficient photothermal conversion performance. These properties are effectively utilized in the photothermal recycling of waste polyethylene and polyethylene terephthalate, marking a significant advance in employing Cu‐based plasmonic materials for sustainable catalytic technology.