Center for Membranes and Advanced Water Technology (CMAT), Khalifa University, Abu Dhabi 127788, United Arab Emirates.
Department of Chemical Engineering, Khalifa University, Abu Dhabi 127788, United Arab Emirates.
ACS Appl Mater Interfaces. 2023 May 3;15(17):20998-21007. doi: 10.1021/acsami.3c00830. Epub 2023 Apr 25.
To address the growing global need for freshwater, it has become essential to use nonpotable saline water. Solar membrane distillation is a potential desalination method that does not need conventional electricity and may cut water production costs. In this study, we develop a photothermal surface heating membrane distillation using a new class of photothermal spacers constructed with TiCT MXene-based nanocomposites. In contrast to traditional membrane distillation, which utilizes energy-intensive bulk feed heating, solar-powered surface heating membrane distillation removes the external thermal energy input requirements, hence reducing operating costs significantly. In particular, three-dimensional (3D)-printing technology was used to fabricate the functional spacer, which allowed the design and materials to be fine-tuned per the needs of the process. Under solar illumination, the printed spacer can exhibit a localized photothermal conversion-driven heating effect near the surface of distillation membranes, which generates vapor pressure strong enough to operate distillation across membranes. Importantly, a two-dimensional TiCT MXene with outstanding photothermal conversion efficiency and stability in hypersaline ionic solutions was incorporated into the 3D-printed spacers as the crucial nanofiller for imparting a local heating effect of feed. The fabricated nanocomposite spacers showed superior photothermal heating response under sunlight with an average permeate flux and energy conversion efficiency of 0.49 kg·m·h and 30.6%, respectively. An enhancement in both photothermal efficiency and permeate flux was noticed as the amount of MXene nanosheets increased in the 3D-printed spacers. This study demonstrates the feasibility of using 3D-printed photothermal spacers for high-performance and sustainable surface heating membrane distillation, providing a promising avenue for further improvement with other photothermal nanofillers or spacer modifications.
为满足全球对淡水日益增长的需求，利用非饮用水源的咸水已成为当务之急。太阳能膜蒸馏是一种有潜力的海水淡化方法，它不需要传统电力，可能会降低水的生产成本。在本研究中，我们开发了一种使用基于 TiCT MXene 纳米复合材料的新型光热间隔物的光热表面加热膜蒸馏。与传统的膜蒸馏利用能源密集型的 bulk feed 加热不同，太阳能表面加热膜蒸馏消除了对外加热能源的需求，从而大大降低了运行成本。特别是，三维（3D）打印技术被用于制造功能间隔物，允许根据工艺需求对设计和材料进行微调。在太阳光照下，打印的间隔物可以在蒸馏膜的表面附近显示出局部的光热转换驱动的加热效应，产生足够强的蒸汽压力以实现跨膜蒸馏。重要的是，二维 TiCT MXene 具有出色的光热转换效率和在高盐离子溶液中的稳定性，被纳入 3D 打印间隔物中作为关键的纳米填充物，赋予进料局部加热效应。所制造的纳米复合材料间隔物在阳光照射下表现出优异的光热加热响应，平均渗透通量和能量转换效率分别为 0.49kg·m·h 和 30.6%。随着 3D 打印间隔物中 MXene 纳米片数量的增加，光热效率和渗透通量都得到了提高。本研究证明了使用 3D 打印光热间隔物进行高性能和可持续表面加热膜蒸馏的可行性，为使用其他光热纳米填充物或间隔物改性进一步提高提供了有前景的途径。
