Plasmonic Cu27S24 nanocages for novel solar photothermal nanoink and nanofilm

Copper sulfide (CuxS) as a plasmonic solar photothermal semiconductor material that expands the light collection range by altering localized surface plasmon resonance (LSPR) to the near- to mid- infrared (IR) spectral region. The versatile synthesis strategies of CuxS nanostructure offer its variability of morphology and provide additional freedom in tuning the optical property. Particularly, nanocage (or nanoshell) has hybridized plasmon resonances as a result of super-positioned nanosphere and nanocavity, which extends its receiving range of solar spectrum and increases light-to-heat conversion rate. Here, we offer novel “nanoink” and “nanofilm” developed from colloidal Cu27S24 nanocages with excellent solar photothermal response. Via combining experimental measurement and theoretical calculation, we estimated the optical properties of covellite Cu27S24. And based on obtained dielectric functions, we then calculated its solar photothermal performance, which was further validated by our experimental measurement. The simulation results showed that hollow Cu27S24 nanocages have excellent solar photothermal performance, and exhibit much higher solar photothermal conversion efficiency than solid Cu27S24 nanospheres.