Chinese scientists at Northwest A&F University have pioneered a solar-powered composite gel that simultaneously produces fresh drinking water and extracts boron from seawater, tackling China’s heavy reliance on imports for this vital lightweight element used in hypersonic weapon fuels and high-performance magnets. This breakthrough addresses dual challenges: freshwater scarcity in coastal regions and securing domestic supplies of boron amid global supply chain vulnerabilities. Reported by the South China Morning Post on December 7, 2025, and detailed in a study published in Science Bulletin, the technology offers a sustainable path forward for resource-strapped nations.
The innovation comes at a critical time, as China consumes the world’s largest share of boron but lacks significant domestic production, importing most from Turkey and the United States. By harnessing abundant solar energy, this method turns an environmental liability—seawater—into valuable assets, potentially reshaping China’s strategic mineral independence.
How the Dual-Function Technology Works?
The gel, dubbed MMS (short for MXene-MgO-sodium alginate), ingeniously combines three key components: MXene, a two-dimensional nanomaterial renowned for its exceptional photothermal conversion efficiency that rapidly heats up under sunlight; magnesium oxide (MgO), a selective adsorbent that efficiently captures boron ions; and a sodium alginate hydrogel matrix that provides structural stability and enables water evaporation. When exposed to simulated solar light equivalent to one sun, the gel achieves an impressive evaporation rate of 2.14 kilograms of water per square meter per hour, while selectively adsorbing 225.52 milligrams of boron per square meter over a nine-hour period in controlled lab conditions.
This process leverages solar-driven interfacial evaporation, where sunlight absorbed by MXene generates localized heat at the air-water interface, accelerating vaporization without bulk heating the entire system, thus maximizing energy efficiency. Simultaneously, MgO targets borate ions prevalent in seawater, binding them firmly to prevent carryover into the condensed freshwater, which tests confirmed as boron-free. The hydrogel’s porous structure facilitates rapid water transport and ion diffusion, making the system both fast and durable.
Boron’s Strategic Importance to China and Global Supply Risks
Boron plays a pivotal role in advanced technologies, particularly as a high-energy fuel additive in scramjet engines that propel hypersonic weapons, igniting intensely upon exposure to oxygen to sustain supersonic combustion in oxygen-poor environments. In China’s military advancements, boron-enhanced fuels enable sustained hypersonic speeds exceeding Mach 5, critical for next-generation missiles and glide vehicles that evade traditional defenses. Beyond defense, boron is indispensable in neodymium-iron-boron (NdFeB) permanent magnets, the strongest type available, powering electric vehicle motors, wind turbine generators, and precision military actuators.
China’s voracious demand—fueled by its dominance in EV production and renewable energy—far outstrips its output, with the country producing negligible amounts compared to global needs. Turkey’s state-owned Eti Maden dominates with roughly 65-70% of worldwide boron concentrate supply from vast deposits in western Anatolia, while U.S.-based Rio Tinto’s Borax operations contribute about 15-20% from California’s Mojave Desert. These concentrations pose risks, as highlighted by the U.S. Geological Survey’s inclusion of boron on its 2025 Critical Minerals List, citing geopolitical tensions, export restrictions, and potential disruptions from natural disasters or trade disputes.
Promising Results from Real-World Testing
Transitioning from lab to field, outdoor experiments in Hong Kong’s humid subtropical climate yielded practical results: the MMS gel produced 5.20 kilograms of freshwater per square meter over a full day and recovered 122.45 milligrams of boron per square meter, with no detectable boron residues in the distillate, ensuring safety for drinking. Remarkably, the material retained its high performance across seven consecutive reuse cycles, demonstrating robustness against real seawater contaminants like salts and organics.
Hong Kong’s tests simulated demanding coastal conditions, including variable sunlight and higher humidity, validating the gel’s stability beyond ideal lab settings. Compared to conventional reverse osmosis desalination, which struggles with boron removal—often leaving concentrations above the World Health Organization’s 2.4 mg/L guideline and risking health issues like reproductive toxicity with chronic exposure—this solar method provides a cleaner, more comprehensive solution.
Agricultural and Economic Benefits of Recovered Boron
The extracted boron proved highly valuable in follow-up applications, enhancing agricultural productivity in controlled trials. When applied to mustard plants, it increased seed germination rates by 13% and boosted biomass accumulation by nearly threefold versus boron-deficient controls, underscoring its role as an essential micronutrient for plant cell wall formation and pollination. This repurposing closes the loop, turning seawater waste into fertilizer for food security in arid coastal farms.
Lead researcher Fan Zhimin, from the Shaanxi Provincial Key Laboratory of Economic Plant Resources Development and Utilization at Northwest A&F University, emphasized that while lab and field data are encouraging, key hurdles remain: optimizing production costs, enhancing scalability for industrial deployment, and integrating with existing desalination infrastructure. Economic analyses suggest potential viability in sun-rich regions, where solar input is free and boron recovery adds revenue streams.
Broader Implications for Global Resource Security
This technology arrives amid intensifying competition for critical minerals, as nations like China seek self-sufficiency to counter supply vulnerabilities exposed by recent geopolitical shifts. By enabling simultaneous desalination and mineral harvesting, it supports United Nations Sustainable Development Goals for clean water (SDG 6) and sustainable industry (SDG 9), particularly in water-stressed areas like China’s eastern seaboard. Future iterations could target other seawater ions, such as lithium or magnesium, expanding its utility in the blue economy.
As discussions on commercialization advance, this MMS gel positions China at the forefront of photo-driven resource extraction, potentially reducing import bills by billions while bolstering high-tech industries. Ongoing research will refine adsorption capacities and long-term durability, paving the way for pilot plants that could transform seawater from a challenge into a strategic asset.
