“…The three characteristic peaks of CuO at 529.85, 531.54, and 532.73 eV are attributed to the lattice oxygen (O latt ), oxygen vacancy (O v ), and adsorbed water molecules (O H 2 O ), respectively. 43,44 Characteristic peaks at binding energies of 529.82, 531.65, and 532.51 eV after 15 min of DBD treatment correspond to lattice oxygen (O latt ), oxygen vacancy and hydroxyl oxygen (O v and O OH − ), and nitrogen–oxygen bonds (O NO 3 −), respectively. 41,42 The disappearance of lattice oxygen in CHN-45 and CHN-H with increasing DBD treatment time indicates the formation of pure Cu 2 (OH) 3 NO 3 , consistent with XRD and TEM results.…”