Investigation of Plasmonic-Enhanced Solar Photothermal Effect of Au NR@PVDF Micro-/Nanofilms

Gold nanospheres (Au NSs) and gold nanorods (Au NRs) are traditional noble metal plasmonic nanomaterials. Particularly, Au NRs with tunable longitudinal plasmon resonance from the visible to the near-infrared (NIR) range were suitable for highly efficient photothermal applications due to the extended light-receiving range. In this work, we synthesized Au NRs and Au NSs of similar volumes and subsequently developed them into Au NR/poly(vinylidene fluoride) (PVDF) and Au NS/PVDF nanofilms, both of which exhibited excellent solar photothermal performance evaluated by solar photothermal experiments. We found that the Au NR/PVDF nanofihn showed a higher solar photothermal performance than the Au NS/PVDF nanofilm. Through detailed analysis, such as morphological characterization, optical measurement, and finite element method (FEM) modeling, we found that the plasmonic coupling effects inside the aggregated Au NR nanodusters contributed to the spectral blue shifts and intensified the photothermal performance. As compared to Au NS/PVDF nanofilms, the Au NR/PVDF nanofilrn exhibited a higher efficient light-to-heat conversion rate because of the extended light-receiving range and high absorbance, as a result of the strong plasmonic interactions inside nanoclusters, which was further validated by monochromatic laser photothermal experiments and FEM simulations. Our work proved that the Au NRs have huge potential for plasmonic solar photothermal applications and are envisioned for novel plasmonic applications.

Automated summary

In this study, gold nanospheres (Au NSs) and gold nanorods (Au NRs) were synthesized and developed into nanofilms with poly(vinylidene fluoride) (PVDF). Solar photothermal experiments showed that Au NR/PVDF nanofilm exhibited higher solar photothermal performance than Au NS/PVDF nanofilm. Detailed analysis revealed that plasmonic coupling effects inside the aggregated Au NR nanodusters contributed to spectral blue shifts and intensified the photothermal performance, resulting in higher light-to-heat conversion rate for Au NR/PVDF nanofilm.