In a promising development for renewable energy technologies, a team of researchers at the University of California, Riverside has embarked on a groundbreaking investigation into a novel method of solar desalination that could dramatically reduce the energy demands typically associated with saltwater treatment. Spearheaded by Luat Vuong, an associate professor of mechanical engineering within the Marlan and Rosemary Bourns College of Engineering, this research focuses on the remarkable yet largely unutilized capabilities of ultraviolet (UV) light, particularly the deep UV spectrum, in facilitating the separation of salt from water.
Desalination is becoming an increasingly critical process as the world’s freshwater resources dwindle and the need for sustainable solutions escalates. Traditional methods of desalination often rely heavily on thermal processes and substantial energy consumption, primarily due to the high temperatures required to boil saltwater and produce steam. However, Vuong and his team have uncovered that the shorter wavelengths of ultraviolet light—specifically around 200 nanometers—can serve as a powerful tool to disrupt the chemical bonds that hold salt and water together, presenting a paradigm shift in the approach to desalination technology.
Historically, UV light in the 300-400 nanometer range has found extensive use in disinfection applications due to its effective bactericidal properties. The innovative aspect of this research lies in the exploration of deep UV light, which promises not only disinfection but also the potential to revolutionize desalination processes. Vuong emphasized that, to their knowledge, this deep UV channel specifically for salt-water separation had not been previously recognized or articulated, setting the stage for further exploration and innovation in the realm of desalination.
The researchers utilized aluminum nitride, a hard and durable ceramic material, to create a wick that enhances the evaporation of saltwater under UV illumination. Unlike conventional solar desalination techniques that depend on materials that heat up, the Vuong team’s method leverages the interaction of specific light wavelengths with the saltwater without raising the overall temperature of the liquid. This breakthrough could herald a new era of non-photothermal desalination processes, which do not rely on thermal energy to achieve evaporation.
Experimental demonstrations have shown that the use of the ceramic wicks under UV light significantly boosts the evaporation rates of saltwater when compared to control samples left in darkness or subjected to longer wavelengths like red, yellow, or infrared light. Vuong noted that the crystalline structure of aluminum nitride is particularly well-suited for emitting UV light efficiently, thereby enhancing the interactions needed for effective salt separation from water.
An intriguing hypothesis posited by the researchers is the possibility of a phenomenon known as “photon upconversion.” This process occurs when lower-energy photons combine to form a single, higher-energy photon. If this upconversion happens without generating excess heat, it could mean that the energy from the UV light is being utilized more effectively, providing a strong alternative to existing thermally-driven desalination methods that lead to thermal inefficiency and energy wastage.
The implications of these findings extend far beyond immediate desalination applications. The potential for the UV-based evaporation system to redefine solar water treatment includes its ability to mitigate the heavy energy requirements associated with reverse osmosis systems, which depend on high-pressure pumps to force saltwater through selective membranes. Furthermore, this method may offer solutions to the environmental challenges posed by the toxic brine waste produced by reverse osmosis, which can cause detrimental effects on marine ecosystems when released into natural bodies of water.
Beyond desalination, the versatile wicking approach may find significance in various fields such as waste management, mineral recovery in extreme conditions, and even in replacing existing swamp cooling systems with more efficient salt water evaporation techniques. This versatility could open new avenues for research and commercial application, providing a more sustainable alternative to current systems that are energy-intensive and environmentally harmful.
Despite this groundbreaking discovery, Vuong cautioned that significant research remains to be conducted before the technology can be engineered for widespread use. While aluminum nitride presents a practical choice due to its affordability, accessibility, and non-toxic nature, it opens up discussions regarding the development of other materials that may equally contribute to enhancing desalination efficiency. The ultimate goal is to foster an array of materials that can be tested for effectiveness in this innovative desalination approach.
As the research team prepares for the next steps in their investigations, they remain optimistic about the path ahead. The novelty of their findings suggests that future studies could not only validate their results but also lead to the development of a new class of desalination technologies that are energy-efficient, effective, and environmentally sustainable—an essential achievement for addressing global water scarcity challenges. With ongoing efforts, this groundbreaking work aims to usher in a future where desalination is a staple in managing freshwater resources with a significantly lower environmental impact.
This innovative study, published in the peer-reviewed journal ACS Applied Materials & Interfaces, marks a significant milestone in the convergence of materials science and environmental engineering. The ability to harness deep UV light effectively presents a compelling case for rethinking existing desalination practices, paving the way for a cleaner, more sustainable, and practical method of obtaining freshwater from saline resources.
In conclusion, the remarkable research led by Luat Vuong and his team at UC Riverside calls attention not only to the innovative applications of UV light in desalination but also to our growing need for energy-efficient solutions. As they continue their exploration into this promising technology, the world may soon witness a transformative change in how we approach one of the most pressing challenges of our time—the sustainable management of our precious freshwater resources.
Subject of Research: Solar desalination using deep UV light
Article Title: Spectrum Selective Interfaces and Materials toward Nonphotothermal Saltwater Evaporation: Demonstration with a White Ceramic Wick
News Publication Date: 10-Oct-2025
Web References: ACS Applied Materials & Interfaces
References: Vuong, L., et al. (2025). Spectrum Selective Interfaces and Materials toward Nonphotothermal Saltwater Evaporation: Demonstration with a White Ceramic Wick. ACS Applied Materials & Interfaces.
Image Credits: UC Riverside
Keywords
Solar desalination, ultraviolet light, aluminum nitride, evaporation, photon upconversion, renewable energy, sustainable technology, water scarcity.
