Advancements in Solar Desalination of Seawater by Various Ti3C2 MXene Based Morphologies for Freshwater Generation: A Review

Abstract

For a few years, we have been witnessing ubiquitous fresh and drinking water scarcity in various countries. To mitigate these problematic situations, many countries relied on non-conventional freshwater generation technologies through solar desalination of seawater. In this manner, we excel the ability of new class 2D Ti3C2 MXenes as a photothermal material (solar absorber) for freshwater generation via the solar desalination technique. In this review, the air–water interfacial interaction is highlighted for improving the evaporation efficiency. To provide the dependence of the desalination efficiency on the microstructure of the solar absorbers, we summarized various forms of 2D Ti3C2 MXenes (aerosol, films, foam, hydrogel, membrane, monolith and porous structure) and their characteristics. These microstructures prevailed ultrahigh photoconversion efficiency. In this aspect, we further explained key features such as light absorption, reflection, multiple internal reflection, hydrophilicity, lower thermal conduction, light-to-heat generation, and salt rejection for achieving efficient desalination output throughout the visible and broadband region. Specifically, we targeted to explore the self-floating and salt rejection nature of various state-of-the-art 2D Ti3C2 MXene structures. Further, we highlighted the long-term stability. Among the above morphologies, Ti3C2 MXene in the form of a membrane is believed to be a promising morphology which effectively desalinates seawater into freshwater. Finally, we highlighted the challenges and future perspectives, which can pave a potential path for advancing the sustainable solar desalination of seawater into freshwater.

Structured Semiconductors in Photocatalysis

“…Finally, a critical comparison among available methods was carried out based on the envisaged application. The second review by Sreedhar and Noh [15] described the advancements in solar desalination of seawater by various Ti 3 C 2 MXene-based morphologies for freshwater generation. The study explained key features such as light absorption, reflection, multiple internal reflection, hydrophilicity, lower thermal conduction, light-to-heat generation, and salt rejection for achieving efficient desalination output throughout the visible and broadband region.…”

Fibrous MXene Aerogels with Tunable Pore Structures for High-Efficiency Desalination of Contaminated Seawater

“…In this context, some pioneering works have tried to assemble 2 D MXene nanosheets into three-dimensional (3 D ) porous aerogels, aiming to obtain more evaporation interfaces [ 16 , 17 ]. However, in the present MXene aerogels, the large and relatively rigid nanosheets are randomly piled up to form irregular and disconnected macropores (25–100 μm) with compact pore walls [ 15 , 18 , 19 ], which fail to form ordered evaporation arrays for a boosted evaporation rate [ 20 ]. Besides, the large pore size is invalid for the interception of emulsified oil droplets since their size is much smaller (< 20 μm) [ 20 ].…”

Efficient Solar Desalination of Seawater Using a Novel Carbon Nanotube-Based Composite Aerogel

“…However, this method also creates direct contact between the solar steam power generation system and a large amount of water, leading to significant heat dissipation [26,27]. While some methods have been proposed to reduce heat loss by reducing the contact area between the system and a large amount of water, the heat loss from the substantial water volume may still significantly restrict the further improvement of the evaporation performance [28,29]. To address this issue, we employ a solar evaporation system that entirely isolates a large amount of water from the evaporation structure, thereby minimizing heat loss.…”