Researchers develop process for inexpensive solar desalinization using aluminium

Solar desalinization, once considered to be too costly to implement in an economic manner, may be achievable in the near future thanks to a process that utilizes aluminium.

Researchers from Georgia Institute of Technology and Nanjing University have developed a process for solar desalinization using self-assembling nanoparticle membranes that are based upon aluminium and other inexpensive materials. The materials used in the described process remain stable even after several uses as well.

“Our plasmon-enhanced solar desalination device can significantly increase the energy transfer efficiency with not only enhanced light absorption, but also more localized heating,” explain the researchers. “To enable efficient solar desalination, broadband and efficient light absorption is the critical first step.”

Plasmonon enhancement means that, when light strikes particular materials, it excites the free electrons within those materials, forming a unified wave, termed a “plasmonon.” Plasmonons are a type of quasiparticle, which is when a microscopically complicated system, such as a solid, behaves as if it contained different weakly interacting particles in free space.

Aluminium has been used in the past for creating plasmonons, but only in narrow wavelengths. These researchers have expanded the use to wavelengths in the solar spectrum, creating “a broadband and efficient aluminium-based plasmonic absorber by self-assembly of the aluminium nanoparticles (NPs) into a 3D porous membrane.”

What the researchers have produced is an inexpensive plasmonic aluminium membrane that utilizes energy from the Sun to turn liquid water into steam, then condensing it into water that is up to four orders of magnitude less salinated.

“Different from most existing desalination strategies, our plasmon-enhanced solar desalination device is highly portable, and thus ideal for personal or miniaturized applications,” the authors conclude. “These aluminium-based plasmonic structures—with low-cost materials and scalable fabrication processes—could therefore provide a portable solution for solar desalination with a minimal carbon footprint.”