A mesoporous MnCo O electrode material is made for bifunctional oxygen electrocatalysis. The MnCo O exhibits both Co O -like activity for oxygen evolution reaction (OER) and Mn O -like performance for oxygen reduction reaction (ORR). The potential difference between the ORR and OER of MnCo O is as low as 0.83 V. By XANES and XPS investigation, the notable activity results from the preferred Mn - and Co -rich surface. The electrode material can be obtained on large-scale with the precise chemical control of the components at relatively low temperature. The surface state engineering may open a new avenue to optimize the electrocatalysis performance of electrode materials. The prominent bifunctional activity shows that MnCo O could be used in metal-air batteries and/or other energy devices.

We present a low-cost laboratory X-ray absorption spectrometer that uses a conventional Xray tube source and bent Johann-type crystal monochromators. The instrument is designed for XAS studies in the 4-20 keV range which covers most K edges of 3d transition metals and L edges of 5d transition metals and actinides. The energy resolution is typically in the range of 1-5 eV at 10 keV depending on the crystal analyser and the Bragg angle. Measurements can be performed in transmission, fluorescence, and imaging modes. Due to its simple and modular design, the spectrometer can be modified to accommodate additional equipment and complex sample environments required for e.g. in situ studies. A showcase of various applications is presented.

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