Plasmonic nanostructures for advanced interfacial solarvapor generation

With the development of artificial microstructures and photothermal conversion, solar vapor generation (SVG) has become one of the most exciting fields of solar thermal energy utilizations, among which plasmonic photothermal evaporators have garnered tremendous interests. As the most important components of solar evaporators, plasmonic microstructures possess at least three appealing photothermal advantages with respect to traditional solar-thermal conversion devices. Firstly, plasmonic microstructures based solar absorbers can achieve highly efficient light harvesting across the entire solar irradiance spectral range with weighted solar absorptivity up to 95% or even higher. Secondly, plasmonic absorbers possess unique local heating effects which originate from both the material level (plasmonic hot spots effect) and system level (interfacial heating effect). Thirdly, plasmonic microstructures can exhibit tunable absorption and thermal emission properties in full wavelength range (from ultraviolet to mid-infrared), ideal for effective thermal loss suppression. In addition, plasmon-based solar vapor generation is also featured by a couple of pronounced materials and/or chemical priorities, such as effective anti-corrosiveness, strong recyclability as well as fast thermal response, which make them ideal candidates for some point-of-use off-grid applications, such as solar desalination for high salt concentration, wastewater treatment, domestic solar sterilization, etc. Aiming at the recent progresses on plasmon assisted efficient solar evaporation, this review demonstrates the photothermal designs on the emerging plasmonic solar vapor generation systems, which mainly focus on the microstructures enabled nanophotonic designs and thermal manipulation. Finally, the plasmonic solar evaporation based photothermal applications and a couple of crucial issues for the future prospective are outlined as well.