Rathore Lokesh Kumar, Bera Ashok
Department of Physics, Indian Institute of Technology Jammu, J&K 181221, India.
ACS Appl Mater Interfaces. 2024 Aug 21;16(33):43670-43681. doi: 10.1021/acsami.4c10367. Epub 2024 Aug 13.
Solar-driven interfacial water evaporation (SIWE) has emerged as a promising avenue for cost-effective freshwater production from seawater or wastewater. However, the simultaneous evaporation of volatile organic compounds (VOCs) presents a limitation for the widespread implementation of this technique. Thus, developing dual-functional evaporators capable of both desalining seawater and degrading VOCs is challenging. Herein, we fabricated an iron-based metal-organic framework MIL-88A/carbon nanotubes (CNTs) poly(vinyl alcohol) hydrogel (MCH) evaporator via the conventional freezing method for solar-driven seawater desalination and simultaneous photo-Fenton VOC degradation. Because of the superior photothermal conversion capability of CNTs, reduced thermal conductivity and water evaporation enthalpy within the hydrogel, and the photo-Fenton activity of rod-shaped MIL-88A, the MCH evaporator exhibits a higher evaporation rate of 2.26 kg m h under 1 sun illumination with simultaneous VOC degradation. The higher hydrophilicity and vertical channels in the MCH evaporator enable its self-salt cleaning ability, facilitating consistent seawater desalination, even in high salt concentrations up to 10 wt %. The synergistic effects of localized heating from CNTs and hydrogen peroxide activation through reactive sites of MIL-88A allow the MCH evaporator to degrade more than 93% of the added phenol during evaporation. This work presents a sustainable and efficient approach for solar-driven seawater desalination, offering simultaneous VOC degradation.
太阳能驱动的界面水蒸发（SIWE）已成为一种从海水或废水中低成本生产淡水的有前景的途径。然而，挥发性有机化合物（VOCs）的同时蒸发对该技术的广泛应用提出了限制。因此，开发能够同时淡化海水和降解VOCs的双功能蒸发器具有挑战性。在此，我们通过传统冷冻法制备了一种铁基金属有机框架MIL-88A/碳纳米管（CNTs）聚乙烯醇水凝胶（MCH）蒸发器，用于太阳能驱动的海水淡化和同时进行光芬顿VOC降解。由于CNTs具有优异的光热转换能力、水凝胶内热导率降低和水蒸发焓降低，以及棒状MIL-88A的光芬顿活性，MCH蒸发器在1个太阳光照下同时进行VOC降解时，蒸发速率高达2.26 kg m⁻² h⁻¹。MCH蒸发器较高的亲水性和垂直通道使其具有自盐清洁能力，即使在高达10 wt%的高盐浓度下也能促进持续的海水淡化。CNTs的局部加热和通过MIL-88A反应位点对过氧化氢的活化的协同作用，使MCH蒸发器在蒸发过程中能够降解超过93%的添加苯酚。这项工作提出了一种可持续且高效的太阳能驱动海水淡化方法，同时实现了VOC降解。
