Bioinspired Au-CuS coupled photothermal materials: enhanced infrared absorption and photothermal conversion from butterfly wings

摘要

A macro centimeter-scale Au-CuS combination nanoparticle system integrated with a sub-micrometer antireflection quasi-photonic structure (SAPS) was synthesized for the first time by utilizing T. helena forewings (T_FW) as a biomimetic template (Au-CuS_T_FW). As-fabricated Au-CuS_T_FW exhibits enhanced broadband infrared absorption and lowered reflectance performance. Such an improvement is attributed to the plasmon-to-exciton/plasmon coupling effect among the Au and CuS nanoparticles as well as the coherent coupling between adjacent resonant systems integrated with the SAPS of the T_FW. Moreover, the Au-CuS_T_FW not only possesses a predominant infrared photothermal conversion performance (30.56%), but also is effective for solar photothermal conversion, for low-temperature applications (T<60 degrees C). Furthermore, the plasmon coupling effect integrates with the SAPS to enhance broadband infrared absorption, and the coherent coupling between adjacent resonant systems enhances the hot power yield, both of which were demonstrated by numerical simulation. Our results offer a new research direction for absorbing and utilizing infrared light and open a novel pathway for improving the absorber of the solar thermal collectors for sunlight photothermal and photoelectric conversion, especially over the infrared range. (C) 2015 Published by Elsevier Ltd.