Seawater electrolysis offers significant potential for decarbonizing the global energy sector, yet its progress has been stalled by challenges such as anode corrosion from chloride ions, unwanted chloride oxidation reactions, and the high cost of catalysts. To overcome these hurdles, self-supported nickel-iron (NiFe) materials have emerged as promising bifunctional catalysts for both hydrogen and oxygen evolution due to their high activity and affordability. Additionally, wood-based carbon (WC) structures are gaining attention as an ideal substrate for these catalysts, thanks to their porous nature and excellent conductivity.

A team of researchers, including Prof. Hong Chen from the Southern University of Science and Technology in China, Prof. Bing-Jie Ni from the University of New South Wales in Australia, and Prof. Zongping Shao from Curtin University in Australia, has devised an innovative approach to enhance the stability of NiFe-based electrodes in seawater electrolysis. Their work, published in the journal Science Bulletin, introduces tungsten into the active NiFe-based catalysts, significantly improving the anodes’ anti-corrosion properties and stability.

The researchers developed a novel WC-supported W-doped NiFe sulfide (W-NiFeS/WC) electrode through a specialized preparation method involving impregnation and sulfidation. This new electrode features a three-dimensional hierarchical porous structure with oriented microchannels, densely anchored W-NiFeS nanoparticles, and high porosity, enhancing both its electrical conductivity and overall efficiency.

Notably, the W-NiFeS/WC electrode demonstrated superior performance and stability in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline seawater, surpassing traditional catalysts. The electrode’s enhanced activity is attributed to its rich redox-active centers and excellent electrocatalytic properties. During OER, the electrode’s structure evolves in situ, generating anti-corrosive tungstate and sulfate species on the surface of active Ni/Fe oxyhydroxides. Additionally, the self-evolved W-NiFeS-decorated NiFeOOH catalyzes HER efficiently.

The low fabrication cost and high effectiveness of the W-NiFeS/WC electrode make it a compelling option for seawater electrolysis, contributing significantly to the advancement of sustainable hydrogen fuel production. This research not only highlights the importance of structural reconstruction in energy conversion reactions but also showcases the potential of repurposing wood waste into carbon structures for advanced electrochemical device design.

By transforming abundant wood waste into efficient catalysts for seawater electrolysis, this work embodies a circular economy approach, minimizing waste generation and promoting sustainable green hydrogen production from seawater.

By Impact Lab