Extended Data Fig. 4: X-ray photoelectron spectroscopy (XPS) spectra.
From: Multi-heteroatom-doped carbon from waste-yeast biomass for sustained water splitting
a, XPS full survey spectrum of the R-2 sample and the corresponding core-level spectra of Ru 2p (b), C 1s (c), P 2p (d), S 2p (e), and N 1s (f).
