Renewable lignin waste transformed into powerful catalyst for clean hydrogen production

Researchers have unveiled a new catalyst made from renewable plant waste that could significantly accelerate clean hydrogen production. The innovative material, created by embedding nickel oxide and iron oxide nanoparticles into lignin-derived carbon fibers, boosts the efficiency and stability of the oxygen evolution reaction, a key step in water electrolysis.

The study, published in Biochar X, demonstrates that the new catalyst achieves a low overpotential of 250 mV at 10 mA cm² and maintains strong performance for over 50 hours at high current density. These results suggest a promising path toward cost-effective and sustainable alternatives to precious metal catalysts that are currently used in industrial water splitting systems.

“Oxygen evolution is one of the biggest barriers to efficient hydrogen production,” said corresponding author Yanlin Qin of the Guangdong University of Technology. “Our work shows that a catalyst made from lignin, a low-value byproduct of the paper and biorefinery industries, can deliver high activity and exceptional durability. This provides a greener and more economical route to large-scale hydrogen generation.”

Lignin, one of the most abundant biopolymers on Earth, is typically burned for low-grade heat. By turning this biomass waste into functional carbon fibers using electrospinning and thermal treatment, the research team created a conductive scaffold that supports and stabilizes the active metal oxide particles. The resulting catalyst, called NiO/Fe3O4@LCFs, features a network of nitrogen-doped carbon fibers that promote rapid charge transfer, high surface area, and strong mechanical robustness.

High-resolution microscopy revealed that the nickel and iron oxides form a nanoscale heterojunction inside the carbon fiber network. This interface plays a crucial role in accelerating oxygen evolution by promoting balanced adsorption and release of reaction intermediates. The combination of the metal oxides with the conductive carbon support enhances electron transport and suppresses particle agglomeration, two common limitations of traditional base metal catalysts.

Electrochemical tests confirmed that the catalyst outperforms single-metal versions, particularly at high current densities needed for practical water electrolysis. The material also shows a Tafel slope of only 138 mV per decade, indicating faster kinetics. In situ Raman measurements and density functional theory calculations support the proposed mechanism, revealing that the engineered interface facilitates key steps in the oxygen evolution pathway.

“Our goal was to develop a catalyst that not only performs well but is scalable and rooted in sustainable materials,” said co-corresponding author Xueqing Qiu. “Because lignin is produced in huge quantities worldwide, the approach offers a realistic path toward greener industrial hydrogen production technologies.”

The study highlights the growing potential of biomass-derived materials in energy conversion systems. By combining renewable carbon supports with rational engineering of metal oxide interfaces, the approach aligns with global efforts to develop low-cost and environmentally friendly solutions for clean energy.

The researchers believe that the strategy can be extended to other metal combinations and catalytic processes, opening new possibilities for designing next-generation electrocatalysts from abundant natural resources.

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Journal reference: Zeng X, Pan Y, Qi Y, Qin Y, Qiu X. 2025. Lignin-derived carbon fibers loaded with NiO/Fe₃O₄ to promote oxygen evolution reaction. Biochar X 1: e011 

https://www.maxapress.com/article/doi/10.48130/bchax-0025-0011 

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About the Journal: 

Biochar X is an open access, online-only journal aims to transcend traditional disciplinary boundaries by providing a multidisciplinary platform for the exchange of cutting-edge research in both fundamental and applied aspects of biochar. The journal is dedicated to supporting the global biochar research community by offering an innovative, efficient, and professional outlet for sharing new findings and perspectives. Its core focus lies in the discovery of novel insights and the development of emerging applications in the rapidly growing field of biochar science. 

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