Solar energy based desalination using solar still is considered as the low-cost efficient method for achieving clean water and the condensation behavior of the still glass cover plays an important role in augmenting the yield. This study aims to improve the water yield and thermal performance of solar still by changing the glass cover wettability using nano-silicon coating through spray technique. Transmission Electron Microscopy image revealed that silicon particles are interconnected and creates a nano-network like structure, whereas the surface area of 45.37 m²/g was exhibited by silicon, signifying its mesoporosity nature. The results showed that the silicon coating changed the condensation behavior of glass cover from film-wise to drop-wise, which augmented the water yield of coated glass solar still by 15.6% as compared to bare glass solar still. Coating durability and ageing analyses revealed marginal reduction in performance and water contact angle of coated solar still even after 100 working days, signifying the durability of coating. The evaporation efficiency of coated glass solar still was 3.6% higher than the bare glass still, owing to the higher heat transfer achieved through drop-wise condensation. Cost analysis of coated solar still revealed freshwater cost per liter of 0.013 US $ with pay-back time of 88 days. Moreover, the water quality analysis of the desalinated water demonstrated excellent quality that is highly suitable for drinking purpose. It is concluded that low-cost and prolonged durability of nano-silicon coating would be highly beneficial in augmenting the overall performance of the solar desalination unit.

使用太阳能蒸馏器的太阳能脱盐被认为是获得清洁水的低成本高效方法，蒸馏器玻璃盖的冷凝行为在提高产量方面起着重要作用。本研究旨在通过喷涂技术使用纳米硅涂层改变玻璃盖板的润湿性，从而提高太阳能蒸馏器的产水量和热性能。透射电子显微镜图像显示，硅颗粒相互连接并形成纳米网络状结构，而表面积为 45.37 m ²/g 由硅表现出来，表示其介孔性质。结果表明，硅涂层改变了玻璃盖板的冷凝行为，从薄膜状到滴状，与裸玻璃太阳能蒸馏器相比，涂层玻璃太阳能蒸馏器的产水量增加了15.6%。涂层耐久性和老化分析表明，即使在 100 个工作日后，涂层太阳能蒸馏器的性能和水接触角也略有下降，这表明涂层的耐久性。由于通过逐滴冷凝实现更高的热传递，镀膜玻璃太阳能蒸馏器的蒸发效率比裸玻璃蒸馏器高 3.6%。涂层太阳能的成本分析显示，每升淡水成本为 0.013 美元，回收期为 88 天。而且，淡化水的水质分析表明水质优良，非常适合饮用。结论是，纳米硅涂层的低成本和持久耐用性将非常有利于提高太阳能海水淡化装置的整体性能。