Directionally tailoring micro-nano hierarchical tower structured Mn0.6Ni1.4Co2Oy toward solar interfacial evaporation

Abstract

Solar interfacial evaporation has been considered as a promising method to alleviate fresh water resources shortage. The shortage of freshwater resources requires advanced materials that can accelerate the evaporation of water by the sun. However, the simple structure of photothermal materials are vitally restricted by finite light absorption. Herein, this work presents a strategy for the synthesis of a spinel-type micro-nano hierarchical tower structure solar absorbent (Mn0.6Ni1.4Co2Oy) with the low forbidden band (=1.56 eV) and high absorption (97.88%). The products show great potential in solar-thermal energy conversion by creating a trapping effect. The prepared solar absorbent and epoxy resin are evenly mixed and then fully immersed in polyurethane (PU) sponge for water evaporation. The hydrophilic and porous Mn0.6Ni1.4Co2Oy @PU sponge can quickly deliver water upwards, suppress the heat loss, and concentrate the absorbed heat on the evaporation of water. The products exhibited an excellent evaporation rate of 2.261 kg m−2 h−1 and an impressive evaporation efficiency of 156% under a single sun exposure. Besides, the samples also can maintain the stability and recycling performance for a long time. These findings show that Mn0.6Ni1.4Co2Oy have great application prospects in the solar interfacial evaporation.