Researchers and Daicel Develop Cellulose Sorbent to Capture Lead from Solar Cell Waste

Researchers from Kanazawa University, Fukushima University, and Daicel Corporation have developed a bio-based sorbent capable of extracting more than 99 percent of lead from liquid waste produced during solar panel recycling. The research, published in ACS Applied Materials & Interfaces and reported by TechXplore (https://techxplore.com/news/2026-10-cellulose-methanol-based-solar-cell.html), introduces a cellulose-derived material targeting critical metals dissolved in organic solvent effluents—an industrial waste stream that resists conventional aqueous recovery methods.

Critical metals such as lead and nickel are essential to manufacturing batteries, electronic devices, and renewable energy infrastructure, but face supply constraints. Conventional recovery techniques like ion exchange and chemical precipitation are designed for aqueous solutions and perform poorly in hydrophilic organic solvents, where the chemical state and properties of dissolved metal ions differ substantially.

To address this limitation, the team from Kanazawa University's College of Science and Engineering and Nano Life Science Institute, Fukushima University's Institute of Environmental Radioactivity, and Daicel Corporation synthesized a sorbent designated DPE6. The material uses cellulose modified with dithiocarbamate functional groups, which contain sulfur atoms that chemically bind heavy metal ions in organic media.

In laboratory evaluations, DPE6 achieved chemical sorption equilibrium within 10 minutes of exposure to contaminated solutions, exhibiting high maximum sorption capacity for lead and nickel in pure methanol and N,N-dimethylformamide (DMF). Spectroscopic analyses using FT-IR, XPS, and XAS confirmed that the sulfur atoms in the dithiocarbamate structure capture the metal ions.

The researchers validated the method on actual organic effluents generated during the recycling of spent perovskite solar cells. DPE6 extracted more than 99 percent of lead from methanol-based recycling waste and approximately 91 percent from DMF-based waste, outperforming standard commercial sorbents that struggle in DMF streams.

Beyond presenting the sorbent, the study systematically clarified how organic solvent properties influence solid-phase metal extraction, providing an empirical baseline for future critical metal reclamation. Kanazawa University and Daicel Corporation have filed an international patent application (PCT/JP2021/34658) covering the technology.