Free‐Standing and Highly Tough 3D Network of Carbon Nanotubes and MXene Constructed by Facile “Egg‐Box” Coordination Mechanism for High‐Efficiency Solar Evaporator

Abstract

Solar steam generation to generating steam through solar light drived surface evaporation (SIE) can be an attractive methodology which utilizes green and inexhaustible solar energy to generate water steam and fresh water in superior efficiency compared with the solar evaporators explored before. However, some drawbacks of the current photothermal conversion materials such as complicated fabrication process, high cost, and low salt tolerance often heavily restrict their wide applications. Herein, we design and develop a green and low‐cost method for constructing free‐standing, elastic and highly tough 3D network of carbon nanotubes and MXene though an efficient “egg‐box” coordination mechanism in only one step for high‐efficiency water evaporation. When the mass ratios of MXene and carbon nanotubes (CNTs) are designed at 2:1, 1:1, 1:1.5 and 1:2, and cross‐linked with sodium alginate (SA) and CaCl2, four composite materials (MCS‐1, MCS‐2, MCS‐3 and MCS‐4) are obtained, among which MCS‐3 shows the most excellent light absorption and hydrophilicity, leading to the best evaporation rate of 1.644 kg m‐2 h‐1, and the highest photothermal conversion efficiency of 96%. Moreover, subject to different harsh environments and durability tests, MCS‐3 also shows desired structural stability and evaporation performance. As demonstrated by its extraordinary photothermal evaporation properties, MCS‐3 could envision a wide range of commercial applications covering wastewater purification and brine sea water desalination etc.This article is protected by copyright. All rights reserved.