Ultralong nitrogen/sulfur Co‐doped carbon nano‐hollow‐sphere chains with encapsulated cobalt nanoparticles for highly efficient oxygen electrocatalysis

Abstract

The development of simple and effective strategies to prepare electrocatalysts, which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), is currently an urgent issue. Herein, an efficient bifunctional electrocatalyst featured by ultralong N, S-doped carbon nano-hollow-sphere chains about 1300 nm with encapsulated Co nanoparticles (Co-CNHSCs) is developed. The multifunctional catalytic properties of Co together with the heteroatom-induced charge redistribution (i.e., modulating the electronic structure of the active site) result in superior catalytic activities toward OER and ORR in alkaline media. The optimized catalyst Co-CNHSC-3 displays an outstanding electrocatalytic ability for ORR and OER, a high specific capacity of 1023.6 mAh g Zn −1, and excellent reversibility after 80 h at 10 mA cm −2 in a Zn-air battery system. This work presents a new strategy for the design and synthesis of efficient multifunctional carbon-based catalysts for energy storage and conversion devices.

Epoxy‐rich Fe Single Atom Sites Boost Oxygen Reduction Electrocatalysis

“…Two dominant peaks located at 164.1 and 165.4 eV can be observed for the high-resolution S 2p of Fe1/NSOC, attributing to the S 2p 3/2 and 2p 1/2 of sulfide species (Figure S7b). [35,36] The small peak at around 168.2 eV is ascribed to the sulfate species. The peak positions of Fe in Fe1/NSOC and Fe1/NC (Figure 2b) reveal that the Fe species appear at their oxidation states instead of metallic states.…”

Catalytic water oxidation mediated by copper‐triazolylpyridine complexes

“…2,3 To fix the issues on the WOR, it is crucial to develop low-cost efficient catalysts. 4 Many homogeneous and heterogeneous nonprecious metal-based WOR catalysts were thereby exploited, including those derived from the first-row transition metals such as Mn, 3,5 Fe, 6,7 Ni, [8][9][10][11] Co [12][13][14][15] , and Cu. [16][17][18] It was demonstrated that the nanostructures of some first-row transition metal compounds supported on carbon materials were very effective heterogeneous catalysts Si-Yang Zhao and Xue-Ling Zhu contributed equally to this work.…”

“…for WOR. 14,15 Meanwhile, some bi-or tri-metallic metalorganic frameworks of the first-row transition metals exhibited a good potential for the application in water oxidation. 7,9,10 A manganese cluster [Mn 12 O 12 (O 2 C-C 6 H 2 (OH) 3 ) 16 (H 2 O) 4 ] was found to be an efficient homogeneous electrocatalyst for WOR with an overpotential of only 74 mV.…”

Robust Electronic Structure: Uncovering the Origins of Fast Oxygen Reduction Kinetics of the NiCo Nanoalloys@N-Doped Carbon

“…Few reports have focused on the change of the electronic structure before and after reconstruction, which is not conducive to an in-depth understanding of how reconstructed active sites determine electrochemical properties. 16,17 Inspired by the above, we prepared a series of NiCo alloys anchored on nitrogen-doped carbon (Ni x Co 6−x @NC, 0 ≤ x ≤ 6) with different electronic structures relying on the tunable Ni/Co ratio. Due to the suitable electronic structure, the reaction kinetics and reconstruction behaviors of Ni x Co 6−x @ NC are regulated.…”

“…To date, the reconstruction behavior of alloys is not clear enough. Few reports have focused on the change of the electronic structure before and after reconstruction, which is not conducive to an in-depth understanding of how reconstructed active sites determine electrochemical properties. , …”