Stanford Scientists have developed a water splitter that runs on an ordinary AAA battery and uses commonly available nickel and iron – no exotic materials required! The “save the planet” potential is clearly there as such a low-voltage, low-amperage conversion opens the potential for solar conversion of water to hydrogen. The discovery was made by Stanford graduate student Ming Gong, co-lead author of the study “Nanoscale nickel oxide/nickel heterostructures for active hydrogen evolution electrocatalysis” published in Nature Communications. “Ming discovered a nickel-metal/nickel-oxide structure that turns out to be more active than pure nickel metal or pure nickel oxide alone,” Dai said. “This novel structure favors hydrogen electrocatalysis, but we still don’t fully understand the science behind it.” The TechEnablement interpretation of the latter statement is that this research opens up a tremendous opportunity for computational modeling to understand and predict potentially more efficient structures. The work was performed by Ming Gong, Wu Zhou, Mon-Che Tsai, Jigang Zhou, Mingyun Guan, Meng-Chang Lin, Bo Zhang, Yongfeng Hu, Di-Yan Wang, Jiang Yang, Stephen J. Pennycook, Bing-Joe Hwang & Hongjie Dai.
Following is the abstract (Nature Communications 5, Article number: 4695 doi:10.1038/ncomms5695, Published 22 August 2014)
Active, stable and cost-effective electrocatalysts are a key to water splitting for hydrogen production through electrolysis or photoelectrochemistry. Here we report nanoscale nickel oxide/nickelheterostructures formed on carbon nanotube sidewalls as highly effective electrocatalysts for hydrogen evolution reaction with activity similar to platinum. Partially reduced nickel interfaced with nickel oxide results from thermal decomposition of nickel hydroxide precursors bonded to carbonnanotube sidewalls. The metal ion–carbon nanotube interactions impede complete reduction and Ostwald ripening of nickel species into the less hydrogen evolution reaction active pure nickelphase. A water electrolyzer that achieves ~20 mA cm−2 at a voltage of 1.5 V, and which may be operated by a single-cell alkaline battery, is fabricated using cheap, non-precious metal-based electrocatalysts.
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