Extreme salt-resisting performance with concentrated seawater To demonstrate the long-term resistance to salt accumulation enabled by TSMD, we conducted a 180-h continuous desalination test of 20 wt % concentrated seawater under 1,000 W m
2 (Figures S25 and S26). The corresponding cumulative heat input was 180 kWh m
2 , equal to the total solar irradiance of z45 days. 23 Figure 5A shows the saline temperature change of a single-stage TSMD device during the 180-h continuous desalination. The temperature of confined saline layer remained stable throughout the test, indicating reliable heat transfer performance. Figures 5B and 5C show the mass change of the collected freshwater and the resulting water Figure 5. Extreme salt-resisting performance of TSMD when desalinating 20 wt % concentrated seawater (A) Saline temperature as a function of time. Periodic temperature fluctuations were observed throughout the test, indicating the existence of strong thermohaline convection. (B) Real-time mass change of the collected water during the 180-h continuous test. © Water production rate as a function of time. The production rate was averaged with a 10-h time interval. A stable production rate was maintained throughout the 180-h operation. Error bars indicate standard deviations. ll Joule 7, 2274–2290, October 18, 2023 2285 Article production rate during the 180-h continuous desalination. The linear profile of mass change (Figure 5B) during 180-h operation indicates a stable water production rate without degradation in performance (Figure 5C). Note that in conventional reliability tests, a cycling operation was adopted. In each cycle, there was a 3–6 h operation under one-sun illumination, followed by a 21–18 h waiting period without solar illu- mination to emulate the nighttime condition and allow the salt rejection (Table S2). In our reliability test, however, we created a more stringent procedure by performing a 180-h continuous test and removing all waiting periods. Considering the salinity (20 wt %) of concentrated seawater used for our test, the total amount of salt rejected during the 180-h operation is equivalent to the accumulated salt in seawater desa- lination (3.5 wt %) throughout z229 day cycling operations (Note S3; Table S2). With the superior salt-resisting capacity, the estimated device lifetime shows 1 order of magnitude improvement compared with the state-of-the-art designs (Table S2).

The paper is very cool though!! Maybe we are all looking towards a future with plenty of fresh water!