S, N co-doped carbon nanotube encased Co NPs as efficient bifunctional oxygen electrocatalysts for zinc-air batteries

Tailoring structural properties of carbon via implanting optimal co nanoparticles in n‐rich carbon cages toward high‐efficiency oxygen electrocatalysis for rechargeable zn‐air batteries

“…This suggests that the high performances of Co@NrC‐0.3 mainly originated from the metal–carbon core‐shell structure, instead of Co single atoms. Previous research works have demonstrated that the electrons from the metal core can be efficiently transferred to the thin carbon shell in the core‐shell‐structured metal–carbon composites owing to their intimate contact, and as such, this carbon layer became more active toward the O 2 adsorption and dissociation and eventually promoted the OER and ORR processes 33 . Specifically, as elucidated by XPS, there was a prominent energy shifting triggered by the strong electron interactions between some implanted metal atoms and pyrrolic N species of the carbon skeleton, which brought about the appearance of the metal–N bond.…”

“…Besides, in the high‐resolution Co 2p spectrum (Figure 2F and ), two different chemical species of Co (0) and Co (II) were obtained. The Co (II) species was mainly due to the oxidation of Co metal 33 …”

“…Previous research works have demonstrated that the electrons from the metal core can be efficiently transferred to the thin carbon shell in the core-shell-structured metal-carbon composites owing to their intimate contact, and as such, this carbon layer became more active toward the O 2 adsorption and dissociation and eventually promoted the OER and ORR processes. 33 Specifically, as elucidated by XPS, there was a prominent energy shifting triggered by the strong electron interactions between some implanted metal atoms and pyrrolic N species of the carbon skeleton, which brought about the appearance of the metal-N bond. Meanwhile, the abundant N-related functional groups (especially pyridinic N and metal-N) in carbon materials feature with the strong electron-withdrawing capability, which could induce more charge on the nearby C atoms and thereby bestow them as active sites toward oxygen electrocatalysis.…”

Facile fabrication of single-atom catalysts by a plasma-etching strategy for oxygen reduction reaction

“…3e, the Cu-SAC/NCbased ZAB exhibited superb battery performance, and the peak power density of the Cu-SAC/NC-based ZAB was as high as 175 mW cm À2 , which was much higher than that of ZAB with Pt/C as the cathode catalyst (140 mW cm À2 ). 43,44 In addition, the specic capacity of the Cu-SAC/NC-based ZAB reached up to 715 mA h g À1 , which is 103 mA h g À1 higher than that of the Pt/ C-based ZAB (612 mA h g À1 ) (Fig. 3f).…”

Efficient Oxygen Reduction and Evolution on 3D Fe/N Co‐doped Carbon Nanosheet‐nanotube Composites with Carbonaceous Heterostructure via in‐situ Growth of Carbon Nanotubes

“…Typical strong peaks at about 44.7°, 65.0°and 82.3°observed in Fe/PVP correspond to the (110), (200), and (211) facet of metallic Fe, respectively. [9] The existence of metallic Fe nanoparticles is due to the reduction of Fe(NO 3 ) 3 -decomposed compounds by the PVP-derived carbon. [10] The XRD patterns at 35.7°, 43.3°, and 54.0°belong to the Fe 3 O 4 species, [11] which is oxidized from metallic Fe in air.…”