Fig. 1
From: Lewis Basicity of Nitrogen-Doped Graphite Observed by CO2 Chemisorption
XPS spectra of HOPG and N-HOPG before CO2 adsorption. a C 1s XPS. b N 1s XPS. c A schematic of each nitrogen configuration in N-HOPG. Hydrogen, carbon, and nitrogen atoms are represented by white, black, and blue balls, respectively