Nitrogen-doped carbon nanotubes derived from Zn–Fe-ZIF nanospheres and their application as efficient oxygen reduction electrocatalysts with in situ generated iron species

Abstract

Nitrogen-doped carbon nanotubes (NCNTs) have been successfully synthesized via the direct solid pyrolysis of Zn-Fe-ZIF and the N content, N doped state, diameter and formation temperature of the NCNTs can be finely tuned by mixing Zn-Fe-ZIF with proper amounts of dicyandiamide (DCDA). DCDA serves as the extra nitrogen supplier and favors the formation of NCNTs at relatively low temperature due to its inducing effect for graphitic structure. The synthesized NCNTs, with iron species and high amounts of graphitic N, exhibit higher catalytic activity than commercial Pt/C as oxygen reduction electrocatalysts in alkaline solution.

One-dimensional nitrogen-containing carbon nanostructures

“…The same hold for NCNTs obtained by pyrolysis of tubular PPy [327]. The role of metallic component in similar systems has been acknowledged for NCNTs derived from Zn-Fe-ZIF nanospheres [222] and FeMWNCNTs composites [436]. Recently, Zelenay's group reported a new type of NCNT/NP composite ORR electrocatalyst [437].…”

High-density iron nanoparticles encapsulated within nitrogen-doped carbon nanoshell as efficient oxygen electrocatalyst for zinc–air battery

“…The crystalline size of iron nanoparticles in D-FC-700 is 22.3 nm, much larger than that in Fe@N-C-700. Therefore, the composition of iron precursor has a significant influence on the properties of outer graphitic carbon nanoshell and inner iron nanoparticle in the encapsulation structure [47].…”

“…The D band is commonly associated with structural defects, while the G band is the result of the first-order scattering of the E2g mode of sp 2 carbon domains. The intensity ratios of D band to G band (I D /I G ) calculated from the peak intensity can be considered a measure of graphitization degree [47,49], which is 0.93 for Fe@N-C-700, 0.89 for Fe@N-C-800 and 0.76 for Fe@N-C-900. Therefore, all the samples have a high graphitization degree in the carbon phase due to the existence of iron nanoparticles during carbonization, which highly facilitates electrical conductivity in the electrocatalytic process.…”

Metal‐Organic Framework‐Based Nanomaterials for Electrocatalysis

“…Owing to the low boiling point of Zn species, the product only consisted of Fe while the presence of the N-precursor favored the formation of a tubular morphology. [63] The unstable impurities were further removed by post treatment with Aqua Regia and HNO 3 . The developed product showed excellent catalytic response (onset potential ≈−0.048 V and half-wave potential ≈−0.183 V vs SCE) and much higher current density in comparison to state-of-theart Pt/C catalysts.…”