Scheme 1
a Schematic illustration showing the fabrication process of Co4N@CoSA/N-CNT/CC. b Scheme showing the mechanism for the formation of single-atom Co. The lamellar cobalt precursor composed of layered cobalt hydroxide-nitrate salts (Co-LHSs) modified with ligand molecules of TEOA on the surface, which possesses a similar structure to that of layered double hydroxides (LDHs), is newly developed in our lab and plays a very important role in achieving high-quality Co4N@CoSA/N-CNT/CC due to the well-controlled transformation of Co-LHSs into ultrafine Co nanoparticles embedded in N-CNTs and highly distributed single-atom Co anchored on N-CNTs.
