Solar-driven surface-heating membrane distillation using Ti₃C₂T_x MXene-coated spacers.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Two-dimensional (2D) MXenes are emerging as highly efficient light-to-heat conversion materials.
• Solar-based desalination, particularly photothermal interfacial evaporation, holds promise for cost-effective water production.
• Membrane distillation (MD) is a viable solar-powered desalination technology.

Purpose of the Study:

• To investigate the use of photothermally functionalized spacers for solar-powered membrane distillation (MD).
• To develop and evaluate metallic spacers coated with Ti3C2Tx MXene for enhanced photothermal conversion and interfacial heating in MD systems.

Main Methods:

• Spray-coating of 2D Ti3C2Tx MXene sheets onto metallic spacers.
• Fabrication of photothermally functionalized spacers for use in MD systems.
• Characterization of photothermal conversion efficiency and water flux under solar illumination.

Main Results:

• The Ti3C2Tx MXene-coated metallic spacers demonstrated stable enhanced water flux up to 0.36 kg·m-2·h-1 for 35 g·L-1 salinity under one sun.
• An energy conversion efficiency of 28.3% was achieved.
• The developed spacers enabled localized photothermal conversion and interfacial feed heating on the membrane surface.

Conclusions:

• The photothermal Ti3C2Tx MXene-coated spacers show great potential for enhancing the performance of solar-driven MD.
• The developed spacers improve the scalability and feasibility of solar desalination processes.
• This work paves the way for advanced photothermal elements in solar MD applications.