Efficient synthesis of nitrogen-doped carbon with flower-like tungsten nitride nanosheets for improving the oxygen reduction reactions

Abstract

A novel three-dimensional (3D) electrocatalyst composite was successfully prepared through a facile hydrothermal method, consisting of tungsten nitride nanosheets with flower-like morphology (WN FNs) and nitrogen-doped carbon black (N-C). Highly crystalline WN FNs were observed to be uniformly distributed in N-C, and remarkably promoted the catalytic activities toward oxygen reduction reaction (ORR) of the N-C. Moreover, the electrochemical results proved that, WN FNs/N-C composite shows a significantly higher ORR activity with a 4-electron transfer pathway and limiting current density of 5.8 mA cm À2 in alkaline solutions. The stability test of the nanocomposite showed less degradation after 5 h and its methanol tolerance also was enhanced compared with Pt/C. The improved performance of the WN FNs/N-C composite can be attributed to its unique configuration and the increased exposure of active sites, which suggests that it could serve as an ideal candidate for developing high performance ORR catalysts.

Tungsten Nitride, Well‐Dispersed on Porous Carbon: Remarkable Catalyst, Produced without Addition of Ammonia, for the Oxidative Desulfurization of Liquid Fuel

“…The major peaks at 2θ of 23.5° and 33.3° are attributed to the characteristic peaks of WO 3 particles that obtained from the tungsten and oxygen species of PTA. The produced material is composed of WO 3 phase when the pyrolysis temperature was increased up to 700 °C; however, another phase W 2 N was observed after the pyrolysis at 800 °C, probably via the phase transformation of WO 3 into W 2 N. The phase transformation to W 2 N was reported to occur usually in the presence of additional NH 3 flow; however, in this study the pANI itself probably acted as the nitrogen source for the formation of W 2 N within pDCs. Further increase of the pyrolysis temperature (up to 900 °C) results in another phase transformation (partial) of W 2 N into metallic tungsten, which was confirmed by the appearance of new XRD peak at 2θ of 40.2°.…”

Highly efficient tungsten/molybdenum-based electrocatalysts for the oxygen reduction reaction: a review

“…120,121 In addition to simple 1D and 2D structures, the 3D structure has a large specific surface area, which can enhance the electrocatalytic performance of the electrocatalyst, and further improve the activity and stability of the ORR. 122 Zhang et al 123 successfully prepared a flower-like 3D electrocatalyst composite, WN–FNs/N–C, by a hydrothermal method. Thanks to its unique 3D structure and the increase in the number of active sites, it provides excellent catalytic stability and activity for the ORR.…”

Recent developments in electrocatalysts and future prospects for oxygen reduction reaction in polymer electrolyte membrane fuel cells

“…4. Flower like tungsten nitride with nitrogen doped carbon for ORR [174] (Reproduced with permission). [167,168] .…”

“…Recently, we reported NiFe 2 O 4 nanoparticles supported on nitrogen-doped graphene (N-Gr) for enhancing ORR performance in PEMFCs relative to pure NiFe 2 O 4 nanoparticles and alone N-Gr [173] . Zhang et al [174] synthesize flower-like tungsten nitride with nitrogen doped carbon to enhanced ORR performance ( Fig. 4 ).…”