Metamaterials for High Efficiency Solar Desalination with Carbon Zero Emission

Solar water desalination attracts significant research interest in producing high-purity fresh water with renewable solar energy, contributing to a circular carbon economy and sustainable development goals. Achieving high-performing solar water desalination systems requires interdisciplinary studies that combine chemistry, material science, physics, mathematics, and computer sciences. This chapter summarizes recent advances in solar desalination technology, focusing on current trends using metamaterials structures. We discuss photo-to-thermal conversion mechanisms in various modern systems and strategies for enhancing light absorption and energy efficiency. We then discuss interface engineering on metamaterials to accelerate the solar evaporation rate, including optimizing surface wetting states, water evaporation enthalpy, and water transportation. In our discussion, we also explore the structural engineering of the entire evaporator, including composing three-dimensional macro-assembly structures and leveraging metamaterials with salt-rejecting properties to achieve long-lasting operating stability. Finally, we provide perspectives on future research opportunities for the challenges ahead in the industry’s large-scale and long-term implementation of solar evaporation technology. We also briefly discuss synergies by coupling solar water desalination with other sustainable technologies in clean fuel generation and wastewater treatment.