Carbon composite materials containing nitrogen-doped carbon nanotubes (NCNTs) possess higher catalytic activity for the oxygen reduction reaction (ORR) in alkaline electrolytes than Pt/C, which makes them promising metal–air battery catalysts. Herein, ternary nitrogen-doped carbon composites (TNCCs) containing N-doped carbon networks with inserted FeN x @NC nanospheroids and bridged by carbon nanotubes were prepared to be used as highly active ORR catalysts, and the mechanism of competitive growth of NCNTs and FeN x @NC was established. The optimized newly developed material (TNCC-10) demonstrated excellent ORR performance comparable to the commercial Pt/C catalyst in a three-electrode system. Its performance in a zinc–air battery as an air cathode catalyst surpassed that of Pt/C in both power density and voltage. The results show the great potential of TNCC-10 as an ORR catalyst in metal–air battery applications.

To obtain a highly active, stable, and binder‐free electrode based on transition‐metal compounds for water splitting, nickel foam‐supported 3D NiMoO4 nanosheet arrays modified with 0D Fe‐doped carbon quantum dots (Fe‐CQDs/NiMoO4/NF) are synthesized. The structure characterizations indicated that 0D Fe‐CQDs are evenly dispersed onto the NiMoO4 sheets of the arrays. The contact angle analysis confirmed that the surface hydrophilia of the arrays is improved after the 0D Fe‐CQDs are deposited 3D on the NiMoO4 sheets. Here, both the activity and durability in electrochemical water splitting are significantly enhanced with the Fe‐CQDs/NiMoO4/NF catalysts. At a current density of 10 mA cm−2, the resultant Fe‐CQDs/NiMoO4/NF revealed an overpotential of only 117 mV for the hydrogen evolution reaction (HER), a relatively low overpotential of 336 mV toward the oxygen evolution reaction (OER), and a Faraday efficiency of up to 99 %. This performance can be attributed to the unique 3D nanosheet array structure, the synergistic effect, and the optimal hydrophilia for gas evolution evolved from the electrode surface.

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Lithium–sulfur batteries are attracting significant attention due to their high specific capacity, reaching 1672 mAh g–1, but their practical applications are hindered by the inherent insulation of sulfur and slow electrochemical kinetics. To overcome these challenges, an in situ method to chemically attach graphene oxide to the surface of sulfur-rich copolymers is developed in this study. Herein, novel conductive sulfur-rich copolymer composites, cp­(S-r-DIB)-Cy-rGO (cpSDG), with a high sulfur copolymerization degree of ca. 52 at % and excellent capacity rates of 1227 mAh g–1 at 0.1 C and 950 mAh g–1 at 1 C, have been obtained by covalently bonding cysteamine-functionalized reduced graphene oxide (Cy-rGO) to the surface of the sulfur-rich polymer matrix (cp­(S-r-DIB)). Compared to a copolymer without Cy-rGO loading and pure sulfur cathodes, the composites display significant enhancements of lithium-ion diffusion coefficients and a higher cycling stability, with a capacity decay of only 0.06% per cycle.

Methanol oxidation catalysts comprising an outer Pt-shell with an inner Ni-core supported on carbon, (Pt-Ni/C), were prepared with either crystalline or amorphous Ni core structures. Structural comparisons of the two forms of catalyst were made using transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and methanol oxidation activity compared using CV and chronoamperometry (CA). While both the amorphous Ni core and crystalline Ni core structures were covered by similar Pt shell thickness and structure, the Pt-Ni(amorphous)/C catalyst had higher methanol oxidation activity. The amorphous Ni core thus offers improved Pt usage efficiency in direct methanol fuel cells.