Wibowo, R.E.; Garcia-Diez, R.; van der Merwe, M.; Duarte-Ruiz, D.; Ha, Y.; Yang, W.; Prokop, M.; Bystron, T.; Wilks, R.G.; Cocchi, C.; Bär, M.: Soft X-ray Emission Spectroscopy of Phosphorus Compounds for Energy Conversion and Storage. The Journal of Physical Chemistry C 129 (2025), p. 7659-7666
10.1021/acs.jpcc.4c08618
Open Accesn Version
Abstract:
Phosphorus (P) is a ubiquitous component of materials for energy conversion and storage. Despite the effectiveness of soft X-ray emission spectroscopy (XES) to characterize these complex materials, XES studies of P-containing compounds are still largely missing. In this investigation, the electronic structure and XES signatures from the P L2,3-edge are probed for nine solid-state P-containing compounds characterized by various oxidation states and chemical environments: GaP(3−), InP(3−), red-P(0), H3P(3+)O3, Na2H2P2(4+)O6, H3P(5+)O4, KH2P(5+)O4, Na2HP(5+)O4, and InP(5+)O4. The XES spectrum of each material exhibits distinct spectral fingerprints, which provide a robust basis for the speciation of complex P-containing samples. Density functional theory calculations shed light on the electronic structure of selected materials and particularly on the effect of phosphorus–oxygen hybridization. This study provides a comprehensive understanding of P L2,3 XES spectral fingerprints across a wide range of oxidation states and chemical environments. These data sets and insights pave the way for dedicated future work, such as in situ and operando investigations of P-containing compounds in energy-related applications, where speciation of P compounds is needed.