Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005.
Laboratory for Nanophotonics, Rice University, Houston, TX 77005.
Proc Natl Acad Sci U S A. 2017 Jul 3;114(27):6936-6941. doi: 10.1073/pnas.1701835114. Epub 2017 Jun 19.
With more than a billion people lacking accessible drinking water, there is a critical need to convert nonpotable sources such as seawater to water suitable for human use. However, energy requirements of desalination plants account for half their operating costs, so alternative, lower energy approaches are equally critical. Membrane distillation (MD) has shown potential due to its low operating temperature and pressure requirements, but the requirement of heating the input water makes it energy intensive. Here, we demonstrate nanophotonics-enabled solar membrane distillation (NESMD), where highly localized photothermal heating induced by solar illumination alone drives the distillation process, entirely eliminating the requirement of heating the input water. Unlike MD, NESMD can be scaled to larger systems and shows increased efficiencies with decreased input flow velocities. Along with its increased efficiency at higher ambient temperatures, these properties all point to NESMD as a promising solution for household- or community-scale desalination.
由于有超过 10 亿人缺乏可获取的饮用水，因此迫切需要将非饮用水源（如海水）转化为适合人类使用的水。然而，海水淡化厂的能源需求占其运营成本的一半，因此替代的、低能耗方法同样至关重要。膜蒸馏（MD）因其低工作温度和压力要求而显示出潜力，但输入水的加热要求使其具有能源密集型。在这里，我们展示了基于纳米光子学的太阳能膜蒸馏（NESMD），其中仅由太阳辐照引起的高度局域光热加热驱动蒸馏过程，完全消除了对输入水加热的要求。与 MD 不同，NESMD 可以扩展到更大的系统，并随着输入流速的降低而提高效率。除了在较高环境温度下的效率提高之外，这些特性都表明 NESMD 是家庭或社区规模海水淡化的一种很有前途的解决方案。
