When Hao Li looks at polluted wastewater, he sees fertilizer. And when he sees plant-derived materials, he sees the raw ingredient for plastic. The trick is doing both at once, cleanly. That is exactly what he and his team at Tohoku University in Japan have now demonstrated — an electrochemical system that turns two waste streams into two valuable products in a single device, powered by sunlight. Their findings were published in Angewandte Chemie on June 8, 2026.
The system centers on a newly engineered catalyst called a nickel-vanadium layered double hydroxide, or NiV-LDH. Built with atomic-scale bridges between nickel, oxygen, and vanadium atoms, this material can efficiently drive two separate chemical reactions inside the same electrolysis cell. At one electrode, it converts a biomass-derived compound called 1,5-pentanediol into glutaric acid — a key industrial chemical used in producing polymers and specialty materials. At the other, it transforms nitrate pollutants pulled from wastewater into ammonia, the foundation of fertilizers and countless industrial processes.
The performance numbers are striking. The catalyst achieved a Faradaic efficiency of 98.5% for converting 1,5-pentanediol into glutaric acid, meaning nearly all the electrical energy went directly into making the desired product. Its efficiency for converting nitrate into ammonia came in at 96.1%, outperforming most previously reported systems. Those are not small improvements — they are a meaningful leap toward practicality.
To prove the system could run beyond a laboratory curiosity, the team operated it continuously for 240 hours using solar power as the energy source. Over that period, the device produced nearly 56 grams of glutaric acid and more than 23 grams of ammonium chloride — a common ammonia-derived compound. That running time far exceeds what many comparable systems have achieved.
Traditional electrolysis methods rely on a reaction called oxygen evolution at the anode, which soaks up energy without generating anything useful. The Tohoku team replaced that step with the oxidation of 1,5-pentanediol, turning what was once wasted energy into a saleable chemical while cutting the system's overall power demand.
"Our goal is to develop technologies that can simultaneously address environmental challenges and chemical production needs," said Li, a distinguished professor at Tohoku's Advanced Institute for Materials Research. "This work shows that waste streams and renewable resources can be transformed into valuable products through a highly efficient and energy-saving process."
The researchers are now planning to scale the technology up and test it using real industrial wastewater. They also want to develop greener methods for separating the final products and to evaluate the full environmental and economic benefits of the process. For communities struggling with agricultural runoff and chemical manufacturers alike, this single system may eventually offer a way forward that makes economic and ecological sense at the same time.