Fig. 3: XPS analysis and porosity.
From: Toward azo-linked covalent organic frameworks by developing linkage chemistry via linker exchange
Comparisons of (a) high-resolution XPS of N 1s and (b) N2 sorption between Im-COF-1 and Azo-COF-1. Note: the supernumerary peak at 403.4 eV in the XPS spectrum of Azo-COF-1 was attributed to the N=O moieties resulting from the adsorbed monomer and residual groups51.
