Hierarchical Co₃O₄ nanorods anchored on nitrogen doped reduced graphene oxide: a highly efficient bifunctional electrocatalyst for rechargeable Zn–air batteries

Abstract

The electrocatalytic activity of the N-rGO/Co3O4 nanocomposites was tuned towards highly efficient bifunctional air-cathodes for Zn–Air batteries.

Electronic Tuning of Core–Shell CoNi Nanoalloy/N-Doped Few-Layer Graphene for Efficient Oxygen Electrocatalysis in Rechargeable Zinc–Air Batteries

“…The N 1s spectrum (Figure d) contained four peaks at 398.4, 399.9, 401.2, and 403.3 eV, corresponding to pyridinic N, pyrrolic N, graphitic N, and oxidized N, respectively. , Results show that nitrogen from the EDTA ligand used to construct CoNi-MOF was incorporated into the carbon framework during the pyrolysis step. According to previous literature, the introduction of graphitic N in the carbon framework is beneficial for increasing the conductivity of graphene shells, ,− whereas pyridinic N can boost the oxygen electrocatalysis . Due to the presence of oxygen-containing groups and N dopants in the carbon shells, the Raman spectrum of CoNi/N-FLG (Figure S6) showed characteristic D and G bands at ∼1350 cm –1 and ∼1590 cm –1 , respectively.…”

“…According to previous literature, the introduction of graphitic N in the carbon framework is beneficial for increasing the conductivity of graphene shells, 20,32−34 whereas pyridinic N can boost the oxygen electrocatalysis. 36 Due to the presence of oxygen-containing groups and N dopants in the carbon shells, the Raman spectrum of CoNi/N-FLG (Figure S6) showed characteristic D and G bands at ∼1350 cm −1 and ∼1590 cm −1 , respectively.…”

“…In this regard, transition metal alloy nanoparticles coated by carbon shells have recently emerged as very promising bifunctional electrocatalysts for reversible ORR/OER. − CoNi alloys are highly active for both ORR and OER. ,− Encapsulation of metal alloy nanoparticles in carbon nanomaterials, to produce core–shell structures, has been shown to preserve the intrinsic catalytic properties of the alloy nanoparticles (via electron penetration effects through the thin carbon shell) while also preventing corrosion of the alloy core in alkaline electrolytes under an applied bias . Moreover, N-doping is an effective approach for enhancing the activity, conductivity and hydrophilicity of carbon materials for enhanced ORR/OER perfromance. − Accordingly, constructing core–shell structured catalysts, based on a CoNi alloy core and N-doped carbon shell, represents a rational approach for efficient and sustained ORR/OER catalysis. The merits of this approach were recently demonstrated by He et al, wherein CoNi alloys/N,O-doped carbon catalysts with a core–shell configuration were fabricated through a facile pyrolysis process involving a bimetallic CoNi-precursor.…”

Effect of Vinylene Carbonate Electrolyte Additive on the Surface Chemistry and Pseudocapacitive Sodium-Ion Storage of TiO2 Nanosheet Anodes

“…Rechargeable sodium-ion batteries (SIBs) are very attractive in this regard, due to the abundance of inexpensive sodium resources [3,5,7,8]. Moreover, the similar electrochemistry and redox potentials of lithium and sodium (−3.02 and −2.71 V vs. SHE, respectively), make it a suitable candidate for efficient electrochemical energy storage [9][10][11]. However, the larger size of Na-ions compared to Li-ions (1.02 and 0.76 Å radius, respectively) hinders their intercalation in the most commonly used Li-ion battery anode material, graphite (interlayer d-spacing of 3.4 Å) [1,12,13].…”

Surface chemistry and structure manipulation of graphene-related materials to address the challenges of electrochemical energy storage

“…(d) The comparison of discharge profiles of ZABs with N-RGO/Co 3 O 4 NRs and commercial PtRuC 20% as oxygen electrode catalysts. Reproduced with permission 45. Copyright 2020, Royal Society of Chemistry.…”