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The preparation of noble metal‐free catalysts for water splitting is the key to low‐cost, sustainable hydrogen generation. Herein, through a pyrolysis‐oxidation process, we prepared a series of Co‐Fe‐Ni trimetallic oxidized carbon nanocubes (Co1‐XFeXNi‐OCNC) with a continuously changeable Co/Fe ratio (X=0, 0.1, 0.2, 0.5, 0.8, 0.9, 1). The Co1‐XFeXNi‐OCNC shows a volcano‐type oxygen evolution reaction (OER) activity. The optimized Co0.1Fe0.9Ni‐OCNC achieves a low overpotential of 268 mV at 10 mA cm−2 with a very low Tafel slope of 48 mV dec−1 in 1 m KOH. At the same time, the stability of the Co0.1Fe0.9Ni‐OCNC is also outstanding; after 1000 CV cycles, the LSV plot is almost coincident. Moreover, the potential remains almost of the same value at 10 mA cm−2 after 12 h in comparison to the initial value. The excellent electrocatalytic properties can be attributed to the synergistic cooperation between each component. Therefore, the Co0.1Fe0.9Ni‐OCNC is a promising candidate instead of precious metal‐based electrocatalysts for OER. [ABSTRACT FROM AUTHOR]

Non‐noble metal‐based metal–organic framework (MOF)‐derived electrocatalysts have recently attracted great interest in the oxygen evolution reaction (OER). Here we report a facile synthesis of nickel‐based bimetallic electrocatalysts derived from 2D nanosheet‐assembled nanoflower‐like MOFs. The optimized morphologies and large Brunauer–Emmett–Teller (BET) surface area endow FeNi@CNF with efficient OER performance, where the aligned nanosheets can expose abundant active sites and benefit electron transfer. The complex nanoflower morphologies together with the synergistic effects between two metals attributed to the OER activity of the Ni‐based bimetallic catalysts. The optimized FeNi@CNF afforded an overpotential of 356 mV at a current density of 10 mA cm−2 with a Tafel slope of 62.6 mV dec−1, and also exhibited superior durability with only slightly degradation after 24 hours of continuous operation. The results may inspire the use of complex nanosheet‐assembled nanostructures to explore highly active catalysts for various applications. [ABSTRACT FROM AUTHOR]

Hydrogen production is one of the most effective methods for combating the global energy crisis. However, improving the electrochemical performance of oxygen‐evolution catalysts is a significant challenge. In this paper, exceptionally active electrocatalysts for oxygen‐evolution reactions (OERs) were successfully developed and characterized by using SEM, TEM, XRD, BET, and X‐ray photoelectron spectroscopy. The nitrogen‐doped hollow‐carbon‐encapsulated bimetallic nanoparticles (MM′‐NHCNPs) were prepared by using folic acid coordination polymerization. The hollow structure and the synergistic effect of bimetallic doping exhibited remarkable catalytic performance and outstanding stability for the OER in a 1.0 m KOH alkaline electrolyte. For the OER, the overpotential of the best catalyst was only 350 mV at a current density of 10 mA cm−2 with a small Tafel slope of 58 mV dec−1. High durability was also demonstrated by the MM′‐NHCNPs. Such an MM′‐NHCNP catalyst with excellent electrochemical properties provides a promising material for OERs. It′s a wrap! Bimetallic nitrogen‐doped hollow‐carbon‐wrapped nanoparticles (MM′‐NHCNPs) were prepared by using folic acid coordination polymerization. Such an MM′‐NHCNP catalyst with excellent electrochemical properties provides a promising material for oxygen‐evolution reactions (see figure). [ABSTRACT FROM AUTHOR]