Figure 3.
Electron structure. High-resolution (a) Fe 2p, (c) N1s, XPS spectra of Fe-Hf/N/C and Fe/N/C. (b) High-resolution Hf 4f XPS spectra of Fe-Hf/N/C and Hf/N/C. (d) Content of different N species for Fe-Hf/N/C and Fe/N/C.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.