Engineering an efficient, cheap, precious metal free electrocatalyst for the oxygen evolution reaction (OER) is a crucial step for a fossil fuel free renewable energy economy. Here we report the utilization of the unique interlayer water environment of birnessite (layered manganese oxide) to enhance the electrocatalytic activity for the OER by nickel hydroxide. Electrocatalytic studies showed that nickel (7.7 atomic %) intercalated into the interlayer of birnessite exhibited an overpotential (η) of 400 mV for OER at an anodic current of 10 mA/cm2. This η is significantly lower than the η values for birnessite (η ~700 mV) and the active OER catalyst β-Ni(OH)2 (η ~550 mV). A detailed experimental and molecular dynamical simulation study of the effect of nickel intercalation on birnessite morphology was carried out. The results give a molecular level insight into why placement of the nickel hydroxide into the birnessite leads to an enhanced activity for the OER in alkaline media.

Enhanced water oxidation by nickel intercataled birnessite

252nd National Meeting (2016)

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