Fig. 5. (a) Heterogenization of NapCo onto graphene through π–π stacking and heteroatom coordination; (b) bright-field TEM image of NapCo@S/N/O heteroatoms doped graphene (SNG); (c) XPS surveys of Co 2p core electron levels of SNG and NapCo@SNG. Inset: the N 1s core electron levels of SNG and NapCo@SNG; (d) HAADF-STEM images of NapCo@SNG where the Co atoms are indicated by the bright spots; (e) UV/Vis spectra of NapCo before and after immobilizing onto SNG.119 Copyright 2019 Wiley-VCH.
