2D/1D MXene/MWCNT Hybrid Membrane-Based Evaporator for Solar Desalination

Yawei Yang,Yan Han,Wenxiu Que,Jianqiu Zhao

doi:10.3390/ma15030929

Abstract

Solar vapor generation through evaporation using photothermal materials is a promising candidate for seawater desalination. The Ti3C2 MXene membrane has exhibited photothermal behavior in solar water evaporation. However, dense packed two-dimensional (2D) MXene membrane with high reflection loss and insufficient vapor escape channels limited its solar evaporation performance. In this work, one-dimensional (1D) multi-walled carbon nanotubes (MWCNT) were added into 2D Ti3C2 nanosheets as the holder to form a 2D/1D hybrid photothermal membrane. Owing to the 2D/1D hybrid structure, more effective broadband solar absorption, water transportation and vapor escape were achieved.

Highlights

Extracting freshwater from saline water sources, known as the desalination, is a common way to solve the freshwater shortage issue all over the world
Several examples of photothermal membranes, including carbon-related materials [4,5], narrow-bandgap semiconductors [6,7,8] and plasmonic nanoparticles [9,10], have been investigated for solar desalination, two-dimensional (2D) Ti3C2 MXene nanosheets with broadband spectrum absorption and an 100% internal light-to-heat conversion efficiency have drawn intensive attention in this area [11,12]. 2D photothermal membranes located at the water-air interface have exhibited vapor generation capability and low heat loss into the bulk water
Adding one-dimensional (1D) multi-walled carbon nanotubes (MWCNT) with excellent hydrophilicity and thermal conductivity into the 2D membrane is considered as an effective strategy for enhancing the porosity, light absorption and thermal conduction to the interfacial water

Summary

Introduction

Extracting freshwater from saline water sources, known as the desalination, is a common way to solve the freshwater shortage issue all over the world. Vapor generation from seawater driven by solar energy has become one of the most promising strategies for clean water harvesting [1]. Several examples of photothermal membranes, including carbon-related materials [4,5], narrow-bandgap semiconductors [6,7,8] and plasmonic nanoparticles [9,10], have been investigated for solar desalination, two-dimensional (2D) Ti3C2 MXene nanosheets with broadband spectrum absorption and an 100% internal light-to-heat conversion efficiency have drawn intensive attention in this area [11,12]. The 2D/1D MXene/MWCNT hybrid membrane was fabricated as the solar absorber for enhancing the vapor generation and seawater desalination performance

Materials

Findings

Preparation of MWCNT Suspension