A laboratory X-ray emission spectrometer for phosphorus K and K study of air-sensitive samples

The analytical chemistry of phosphorus-containing materials is often impeded by the long measurement times and relatively large sample masses needed for P-31 NMR spectroscopy, by the scarcity and access limitations of synchrotron beamlines operating in the energy range of the P K-edge, by the challenges posed by species interconversion during liquid extraction, and by the considerable air-sensitivity typical of many phosphorus-containing materials and nanophases. To this end, we report the design and operation of a new laboratory-based spectrometer to simultaneously perform P K alpha and K beta X-ray emission spectroscopy (XES) while being housed in a research-grade controlled-atmosphere glovebox. Demonstration studies on nickel phosphide nanophases illustrate the importance of air-free XES and the value of simultaneous K alpha and K beta spectroscopy for identifying the P oxidation state and for investigating nanoscale influences on valence level electronic structures.