Bio‐Templated Silver Nanopatterns for Photothermal and Antifogging Coatings

Transparent photothermal coatings based on plasmonic noble metals often face a trade-off between achieved temperatures and transmittances. This challenge arises from the fact that plasmonic nanoparticles (NPs), which rely on their size and structures, selectively absorb light of various wavelengths and convert it into heat. In the cases of randomly arranged plasmonic NPs, absorbances are predominantly in the visible range, leading to lowered transmittances. In this work, the self-assembly behavior of a biotemplate containing flexible potato virus A (PVA) is used to produce network-like surface patterns with controllable intermittent vacancies. These templates effectively anchor silver nanoparticles (AgNPs), forming dense arrays of plasmonic hotspots interspersed with vacant regions. With this approach, a temperature increase of 21 °C above ambient temperature under 1-sun radiation is achieved while maintaining a visible light transmittance as high as 78% measured at 550 nm wavelength. The PVA biotemplated AgNPs show excellent potential as antifogging coating, exhibiting 2–3 times faster defogging rates compared to uncoated samples in both indoor and outdoor conditions. Overall, a platform is presented for biotemplating metal NPs, the development of long-range surface patterns with controlled vacancies, and the demonstration of transparent photothermal activity with an antifogging application.