The desalination of seawater has the potential to address the increasing demand for potable water. Specifically, solar-thermal water desalination can generate clean water without relying significantly on fossil energy. However, the inefficient use of solar energy often limits the overall performance, which affects the rate, efficiency, and feasibility of large-scale implementation. This study shows the use of a spectrally-selective nanomaterial as an absorber to improve the performance of solar-thermal desalination. This material is designed to maximize the absorption of sunlight and minimize the loss of energy by thermal emission, which allows higher throughput and efficiencies compared to broadband absorbers. In this study, we show a 10% enhancement in the evaporation rate of water by using a selective absorber compared to a graphite absorber. We demonstrate a scalable approach involving the use of wicking materials interfaced with the spectrally-selective absorber for the desalination of saline water to get 73% of overall efficiency using a solar flux of one sun. This demonstration of an inexpensive strategy for producing clean water can potentially transform the field of solar-thermal desalination to address the rising demand for water.

海水淡化具有解决饮用水需求增长的潜力。具体而言，太阳热水淡化可以产生清洁水，而无需极大地依赖化石能源。但是，太阳能的低效使用通常会限制整体性能，从而影响大规模实施的速度，效率和可行性。这项研究表明，使用光谱选择性纳米材料作为吸收剂来改善太阳热脱盐性能。这种材料旨在最大程度地吸收太阳光，并最大限度地减少热量散失造成的能量损失，与宽带吸收器相比，它具有更高的吞吐量和效率。在这项研究中，与石墨吸收剂相比，使用选择性吸收剂表明水的蒸发速率提高了10％。我们展示了一种可扩展的方法，该方法包括使用芯吸材料与光谱选择性吸收剂相连接，以使用一个太阳的太阳光通量使盐水脱盐，从而获得总效率的73％。这种生产清洁水的廉价策略的展示可能会改变太阳能热淡化的领域，从而满足对水的不断增长的需求。