Aligned Attapulgite-based aerogels with excellent mechanical property for the highly efficient solar steam generation

Abstract

Solar steam generation has attracted much attention due to its efficient and ecofriendly characteristics for application in water desalination and wastewater treatment. Many strategies have been developed to prepare the photothermal conversion materials. However, it is a challenge for preparing the materials with high energy efficiency, long durability and excellent salt resistance under 1 kW·m−2 illumination by using low-cost materials and simple method. Here, we report an ATP (Attapulgite) based PArG aerogel with low thermal conductivity (0.167 W·m−1·K−1), high mechanical property and superhydrophilicity by using combination of physical/chemical crosslinking of the ATP, PVA, GO and PA and freeze-drying for the efficient solar steam generation. The as-prepared PArG-A30 aerogel shows aligned three-dimensional porous structure and possesses high evaporation performance both in salt solution and the simulated seawater. The evaporation rate is calculated to be 1.4914 kg·m−2·h−1 for pure water, 1.4382 kg·m−2·h−1 for 20% of NaCl solution and the corresponding energy conversion is found to be 89.5% and 86% under 1 kW·m−2 illumination. In addition, the as-prepared PArG-A30 aerogel shows excellent durability and salt resistance in 20% NaCl solution, indicating the excellent the desalination performance of the resultant PArG-A30 aerogels. This study may offer a new approach to scalable fabricate a novel solar steam generator for the efficient solar steam generation by using simple method and low-cost materials.