Spatial Decoupling of Light Absorption and Scattering Centers in Plasmon-assisted Bubble Column Evaporator for Solar Steam Generation

Abstract

Solar water evaporation offers a promising route to enable large-scale conversion and storage of solar energy. Utilizing nanofluid with superior photothermal properties in solar energy systems is an effective method to improve their thermal performance. However, the bulk temperature increase of fluid will induce thermal loss, which reduces the phase-change evaporation at air-water interface. Here, we demonstrate a plasmon-assisted bubble column evaporator that functionally deconvolutes its light absorption and scattering centers for solar steam generation. Varying the gas fraction of bubbles and their surrounding particle-dispersed liquid marbles makes it possible to examine the interplay between the light absorptive nanoparticles and the scattering properties along bubble-liquid interfaces. This particle-stabilized gas/liquid dispersion optimizes the contributions of light harvesting, heat management and mass transport to the overall device performance, leading to a three-fold enhancement of evaporation under two-sun irradiation. Our findings pave a new way to enhance evaporation in nanofluid suspensions and speed the development of solar thermal system for practical applications.