Parabolic concave surface modified by carbonized micro-cone array on rattan enables multi-dimensional light harvest for bio-based solar evaporators

Abstract

It is imperative to delve into multi-dimensional light harvest solution that enhance vapor production without increasing solar energy input. Herein, we demonstrate a rattan-based evaporator with parabolic concave surface modified by carbonized micro-cone array. The parabolic concave surface facilitates multiple reflections of light, which could exhibit peak evaporation ability under not vertically irradiated light. The carbonized micro-cone array not only multiply enlarges available evaporation area and promotes the full directional release of vapor, but also forms the Marangoni flow which drives a liquid circulation to facilitate salt reflux. The design of our evaporator achieve a evaporation rate of 2.06 kg·m−2·h−1 with 94.48 % energy conversion efficiency credited to 90.27 % light absorption owing to the distinctive and sophisticated surface. Simultaneously, this evaporator showcases stable performance for long-time use and achieves a commendable salt purification rate of 99.6 %. We harness the widespread grow rattan in potable-water-scarce regions/countries, forming an integration of complementary resources.