Water is an essential element for life. A minimum of 5L/day of drinking water is required for a person to survive with normal activities.^[1] Currently, 2.1 billion people globally have limited access to safe drinking water. Additionally, about 6% of deaths in underdeveloped countries are caused by drinking unsafe water.^[2] To address water scarcity, the research community has proposed a variety of solutions to alleviate the drinking water crisis, such as solar desalination, reverse osmosis (RO), atmospheric water harvesting, and capacitive deionization technology (CDI). However, the high energy consumption, low efficiency and/or high production cost of these technologies greatly hinder the future development of these devices. However, with the development of material science and nanotechnology, some profound changes are taking places in these technologies. This special issue features four review papers and three research papers that focus on solar desalination, atmospheric water harvesting and CDI for clean drinking water, which aim to further promote the development of related technologies.

Direct solar desalination, which produces freshwater directly using solar energy with minimum carbon footprint, is considered to be one of the most promising technologies to alleviate the water shortage crisis. However, the traditional bulk water heating method is inefficient (≈40%). Recently, interfacial solar vapor/steam generation has been proposed to improve heat localization at the liquid surface and has achieved ≈90% solar‐to‐vapor conversion efficiency under 1 Sun. In this special issue, a review paper contributed by Irshad et al. (article number 2000055) systematically summarizes the progress of solar vapor/steam generation and constructively points out the key directions of future research. As mentioned in this review, the long‐term stability of absorbers is still a challenging issue. Zhuang et al. (article number 2000053) and Gu et al. (article number 2000063) demonstrate two advanced materials, reduced graphene oxide hydrogel membranes and three‐dimensional honeycomb chitosan‐based aerogels, which exhibit long‐term stability without compromising the water evaporation rate (> 1.7 kg m⁻² h⁻¹). These represent competitive materials for salt‐resistant absorbers. Meanwhile, an impressive work hoping to thoroughly solve the problem of salt‐rejecting of absorbers is presented by Bian et al. (article number 2000077) who select a highly efficient selective absorber and use convection between the selective absorber and water to heat the water (the absorber was suspended above the water instead of traditional direct contact). The results show that the evaporation efficiency is able to reach 1.94 kg m⁻² h⁻¹. Additionally, it is worth noting that the advantages of the regulation and utilization of infrared light have been reported recently, with the use of selective absorbers to obtain higher efficiency, and the use of radiative cooling to enhance condensation, etc., becoming a key focus for researchers. In this special issue, Li et al. (article number 2000058) offer a fundamental understanding of spectrum design, alongside a discussion of recent progress and future directions of for this research.

Atmospheric water harvesting, which captures the moisture from air and then condenses the captured moisture into liquid water, is a promising technology to resolve the water crisis in arid regions. Compared with traditional inorganic salts, zeolites, etc., recently developed materials, such as MOFs/COFs and hydrogels, are demonstrated to have lower desorption energy and/or humidity adsorption. In this special issue, Zhuang et al. (article number 2000085) contribute a review paper to discuss and provide a perspective regarding various atmospheric water harvesting technologies, especially for solar atmospheric water harvesting with the above‐mentioned advanced materials. In addition, CDI technology is also a competitive technology that uses electrode materials to extract positive and negative ions in the feed solution to achieve water purification. Liu et al. (article number 2000054) review various sodium‐ion intercalation materials as highly efficient CDI electrodes, and provide some instructive perspectives. We believe that these papers will be helpful for both the research and industrial community to achieve new milestones and to shape future research directions.

As United Nations Development Programme 6 mentions,^[3] with the increase of drought and desertification, more and more countries will suffer from water shortages. By 2050, it is predicted that at least one in four people will suffer from recurring water shortages. Herein, learning from the perspectives of the authors in this special issue, we believe that more efficient devices based on new mechanisms, new materials, and new structures should be developed. In addition, the stability and price of the devices need to be considered in the long‐term research and industrial plan. The community should also actively communicate and collaborate with industry and the public to apply these advanced technologies into practice to alleviate the drinking water challenges of the future.

水是生命必不可少的元素。一个人每天正常活动至少需要5升水。^{[ 1 ]}目前，全球有21亿人有限地获得安全的饮用水。此外，在不发达国家中约有6％的死亡是由于饮用不安全的水造成的。^{[ 2 ]}为了解决水资源短缺问题，研究团体提出了多种缓解饮用水危机的解决方案，例如太阳能淡化，反渗透（RO），大气集水和电容去离子技术（CDI）。但是，这些技术的高能耗，低效率和/或高生产成本极大地阻碍了这些设备的未来发展。但是，随着材料科学和纳米技术的发展，这些技术发生了一些深刻的变化。本期特刊以太阳能淡化，大气集水和清洁饮用水的CDI为重点的四篇评论论文和三篇研究论文，旨在进一步促进相关技术的发展。

直接太阳能淡化技术可使用最少的碳足迹直接使用太阳能生产淡水，被认为是缓解缺水危机的最有前途的技术之一。但是，传统的散装水加热方法效率低（约40％）。最近，已经提出了产生界面太阳蒸气/蒸汽的方法，以改善液体表面的热定位，并在1 Sun下实现了约90％的太阳-蒸气转换效率。在本期特刊中，Irshad等人撰写了一篇评论文章。（文章编号2000055）系统地总结了太阳蒸气/蒸汽产生的进展，并建设性地指出了未来研究的关键方向。如本评论所述，吸收器的长期稳定性仍然是一个具有挑战性的问题。庄等。（商品号2000053）和Gu等人。^-2 h ^-1）。这些代表了抗盐吸收剂的竞争材料。同时，Bian等人提出了一项令人印象深刻的工作，希望能彻底解决吸收器的排盐问题。（文章号2000077）选择了一种高效的选择性吸收器，并利用选择性吸收器和水之间的对流来加热水（吸收器悬挂在水面之上而不是传统的直接接触）。结果表明，蒸发效率达到1.94 kg m ^-2 h ^-1。另外，值得注意的是，近来已经报道了调节和利用红外光的优点，通过使用选择性吸收剂以获得更高的效率，以及通过辐射冷却来增强冷凝等，成为人们关注的焦点。对于研究人员。在本期特刊中，Li等。（文章编号2000058）提供了对频谱设计的基本理解，并讨论了该研究的最新进展和未来方向。

收集大气中的水分然后将捕获的水分冷凝成液态水的大气水收集技术是解决干旱地区水危机的一项有前途的技术。与传统的无机盐，沸石等相比，最近开发的材料（例如MOF / COF和水凝胶）具有较低的解吸能和/或湿气吸附能力。在本期特刊中，庄等。（文章编号2000085）撰写了一篇评论文章，以讨论和提供有关各种大气水收集技术的观点，尤其是使用上述先进材料进行太阳能大气水收集的观点。此外，CDI技术也是一项竞争性技术，它使用电极材料在进料溶液中提取正离子和负离子以实现水净化。刘等。（商品编号2000054）回顾了钠离子插层材料作为高效的CDI电极，并提供了一些指导性的观点。我们相信这些论文将对研究界和工业界都有帮助，以实现新的里程碑并塑造未来的研究方向。

正如联合国开发计划署6提到的，^{[ 3 ]}随着干旱和荒漠化的加剧，越来越多的国家将遭受缺水之苦。预计到2050年，至少四分之一的人将遭受经常性的水短缺之苦。在此，从本期特刊作者的角度学习后，我们认为应开发基于新机制，新材料和新结构的更有效的设备。此外，在长期研究和工业计划中还需要考虑设备的稳定性和价格。社区还应积极与业界和公众进行沟通和合作，以将这些先进技术付诸实践，以减轻未来的饮用水挑战。