Self‐Supported Hierarchical Shell@Core Ni₃S₂@Ni Foam Composite Electrocatalyst with High Efficiency and Long‐Term Stability for Methanol Oxidation

Abstract

Direct methanol fuel cells are promising renewable energy devices for automobiles and portable electronic devices. The development of high effciency, poison tolerance, long‐term stability, and noble metal‐free electrocatalysts for methanol oxidation is still a major challenge. Herein, we develop a noble metal‐free, 3D self‐supported, defect‐rich, hierarchical shell‐core structured Ni3S2 composite on Ni foam as electrocatalyst. This electrocatalyst shows a good activity, poison tolerance, and long‐term durability towards methanol oxidation in alkaline media. It shows the lowest onset potential (−340 mV vs. Hg/HgO) among all the Ni‐based catalysts reported up to date and a Pt‐level specific activity. The methanol oxidation peak current of the electrocatalyst retains more than 97.5 % even after 5,000 voltammetry cycles in 0.5 M KOH+1 M CH3OH. The morphology and composition of the electrocatalysts before and after stability test were characterized by SEM, TEM, XRD, and XPS. The high activity, poison tolerance, and stability are attributed to the binder‐free, directly grown Ni3S2 shell on the Ni foam backbone, the lattice defect sites, and the synergetic effects between the in‐situ formed active NiOx core and Ni3S2 shell during methanol oxidation. This work indicates that the self‐supported hierarchical shell‐core Ni3S2@Ni foam electrocatalyst is a viable alternative for commercial Pt‐based electrocatalyst applied in fuel cells.

Noble Metal‐Free CoSx/NiSx Heterojunction for Photo‐Assisted Methanol Electrooxidation

“…RHE) for methanol oxidation is noticed. The onset potential of our proposed CoS x /NiS x heterojunction was comparable to the previously reported cobalt/nickel based electrocatalyst, [13a] but which was higher than the Pt based electrocatalyst, [7,12b] these remain to be improved in the latter studies. When the potential increased to 1.5 V ( vs .…”

MoS2/Ni3S2/Reduced Graphene Oxide Nanostructure as an Electrocatalyst for Alcohol Fuel Cells

“…The composite consisting of NiS and carbon nanofiber was also synthesized and evaluated by Maafa for the oxidation of methanol . Hierarchical shell@core Ni 3 S 2 @Ni foam has been proposed as an efficient and stable nanocatalyst for MOR by Yuan et al Although MoS 2 and nickel sulfides together have been investigated in electrochemical studies and several other applications, − so far, the composite containing these metal sulfides has not been reported for MOR and EOR processes.…”

Engineering Flower-like Ni3S2 on Nanoporous CuAg Alloy Heterostructure for Efficient Methanol Oxidation Reaction

“…22 Yuan's work involved the synthesis of a layered core−shell Ni 3 S 2 @NF composite via a hydrothermal method, which showed significant promotion for MOR. 23 Notably, Ni 3 S 2 nanomaterials have emerged as potential electrocatalysts of great promise, owing to their unique electronic structure and properties. However, there have been limited studies on improving the MOR performance using Ni 3 S 2 catalysts.…”

“…Abdullah and co-workers demonstrated the positive effect of NiO/NF catalysts on methanol oxidation . Yuan’s work involved the synthesis of a layered core–shell Ni 3 S 2 @NF composite via a hydrothermal method, which showed significant promotion for MOR . Notably, Ni 3 S 2 nanomaterials have emerged as potential electrocatalysts of great promise, owing to their unique electronic structure and properties.…”