Mesoporous S,N-Codoped Carbon/Co_xS_y Hybrid Catalyst for Efficient Bifunctional Oxygen Electrocatalysis in Rechargeable Zn–Air Batteries

Abstract

Developing high-active and low-cost bifunctional oxygen catalysts is of great concern but challenging for the commercial application of Zn–air batteries (ZABs). Herein, a hybrid material, consisting of encapsulated cobalt sulfide (Co x S y ) particles and S,N-codoped carbon (SNC), was prepared via a simple template-assisted pyrolysis process. The as-prepared catalyst possesses a mass of mesopores and abundant N-doped coordination species. By a feat of synergistic effects between the encapsulated Co x S y and SNC, the hybrid displays superior electrocatalytic performances toward both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline electrolytes, for example, a positive ORR half-wave potential of 0.802 V and a low OER overpotential of 336 mV at 10 mA cm–2, as well as excellent electrochemical stability. Moreover, the as-prepared catalyst applied in ZABs exhibits a high power density (132 mW cm–2), good rate capability, outstanding rechargeable ability, and robust cycling stability (500 h at 2 mA cm–2).

Peach Gum‐Derived S,N Co‐Doped Nanoporous Carbon Coupled with Layered Double (Ni, Fe) Hydroxide for Efficient Bifunctional Oxygen Electrocatalysis in Zn‐Air Batteries

“…The X‐ray photoelectron spectroscopy (XPS) survey spectrum of SNC in Figure S1d displays the presence of C (89.5%), N (3.2%), O (5.5%) and S (1.8%). Specially, the C 1s spectrum in Figure 1d can be fitted into C−C sp 2 , C−C sp 3 /C−S, C−N and –COOH [3b] . The appearance of C−S band and C−N band confirms the presence of S‐ and N‐dopant.…”

Tailored Crafting of CoP/Ni2P Nanoparticles Coupled with N-Doped Nanoporous Carbon to Enable Efficient Hydrogen and Oxygen Evolution

“…To reveal the evolution of the surface structure, XPS of the sample was tested at different times. After tests for 6 and 70 h, the Co 2p and Ni 2p XPS spectra reveal that the peaks of metallic species in TMPs disappear, and the peaks of oxidized species become predominant (Figure S8b,c), suggesting the surface oxidation of TMP nanoparticles. , Simultaneously, the P 2p and O 1s XPS spectra reveal the loss of the surficial P element and the formation of the metal O band (Figure S8d,e), respectively. The results indicate the formation of Co/Ni oxides and/or (oxy)­hydroxides during OER tests in an alkaline electrolyte, which actually serves as the catalytic active species toward OER.…”

“…To investigate the electrocatalytic performances of asprepared catalysts, linear scan voltammetry (LSV) was carried spectra reveal that the peaks of metallic species in TMPs disappear, and the peaks of oxidized species become predominant (Figure S8b,c), suggesting the surface oxidation of TMP nanoparticles. 6,33 Simultaneously, the P 2p and O 1s XPS spectra reveal the loss of the surficial P element and the formation of the metal O band (Figure S8d,e), respectively.…”

“…Although they exhibit highly electrocatalytic activities, their exorbitant prices, scarce resources, and undesirable durabilities remain the biggest obstacles to massive commercialization for water electrolysis. Consequently, various nonprecious metal- and metal-free-based catalysts have been studied extensively as ideal substitutes for noble metal-based electrocatalysts, such as transition metal phosphates, chalcogenides, − oxides, and (oxy) hydroxides. , Unfortunately, for practical applications, catalytic efficiency and durability still imminently need to be further boosted.…”

Hierarchical Porous Carbon Sponge with High Capacitance and High Catalytic Activity for the Oxygen Reduction Reaction

“…Among of them, 2D graphene is highly conductive and has large theoretical surface areas; however, it suffers from overlapping layer by layer, which significantly reduces the available surface area, leading to poor utilization of the active sites on it. , The 3D porous carbon materials are highly preferred, as a result of the large surface area and porous structures facilitating mass transportation. To obtain 3D carbon materials, a diversity of organic precursors have been introduced. − Melamine foam (MF) has an elastic organic skeleton with macropores, and after carbonization, the macropores could be inherited to facilitate mass transportation; therefore, it has been adopted as a precursor to prepare porous carbons. , However, one drawback is that the macropores of MF are as large as several micrometers, which leads to a low surface area and, thus, remarkably decreases the volume density of active sites. Metal–organic frameworks (MOFs) are a family of newly emerging carbon precursors of porous structures.…”