Mass-based photothermal comparison among gold nanocrystals, PbS nanocrystals, organic dyes, and carbon black

Gold nanocrystals have attractive plasmon-enabled photothermal conversion properties, which have been widely employed for photothermal therapy and solar energy harvesting. For practical applications, the mass-normalized photothermal conversion performance is often desired to be known for Au nanocrystals with different shapes and sizes and for different nanomaterials. We study the photothermal conversion performances of differently shaped and sized Au nanocrystals and compare them with those of PbS nanocrystals, carbon black, and organic dyes at the same mass concentrations. Both the mass-normalized extinction cross section and the photothermal conversion efficiency of Au nanocrystals decrease as their size is increased. The photothermal conversion performance of carbon black is comparable to that of relatively small Au nanocrystals, while the photothermal conversion performance of organic dyes and PbS nanocrystals is inferior to that of Au nanocrystals. Our results are useful for the design of Au nanocrystals and the choice of nanomaterials for photothermal applications.