The development of highly efficient and durable non-noble metal electrocatalysts for the hydrogen evolution reaction (HER) is significant for clean and renewable energy research. This work reports the synthesis of N-doped graphene nanosheets supported N-doped carbon coated cobalt phosphide (CoP) nanoparticles via a pyrolysis and a subsequent phosphating process by using polyaniline. The obtained electrocatalyst exhibits excellent electrochemical activity for HER with a small overpotential of -135 mV at 10 mA cm and a low Tafel slope of 59.3 mV dec in 0.5 m H SO . Additionally, the encapsulation of N-doped carbon shell prevents CoP nanoparticles from corrosion, exhibiting good stability after 14 h operation. Moreover, the as-prepared electrocatalyst also shows outstanding activity and stability in basic and neutral electrolytes.

Graphene oxide (GO), an emerging material ornamented with oxygen-containing functional groups, is becoming a promising alternative for various applications. The piranha solution treatment of GO can increase oxygen-containing functional groups and result in improved graphene oxide (IGO), as well as restore the functional groups lost because of the reaction. It is found that GO can oxidize the amine to the corresponding imine in the absence of oxygen and a catalyst, and the obtained IGO even shows higher activity. In addition, the piranha solution can partially restore the reactivity of GO after the reaction. The different roles of oxygen-containing functional groups in the oxidative coupling reaction are investigated. A possible reaction mechanism for the oxidation of benzylamine to N-benzylidene benzylamine is also proposed.

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Exploring the economical, powerful, and durable electrocatalysts for hydrogen evolution reaction (HER) is highly required for practical application. Herein, nanoclusters-decorated ruthenium, cobalt nanoparticles, and nitrogen codoped porous carbon (Ru-pCo@NC) are prepared with bimetallic zeolite imidazole frameworks (ZnCo-ZIF) as the precursor. Thus, the prepared Ru-pCo@NC catalyst with a low Ru loading of 3.13 wt% exhibits impressive HER catalytic behavior in 1 M KOH, with an overpotential of only 30 mV at the current density of 10 mA cm−2, Tafel slope as low as 32.1 mV dec−1, and superior stability for long-time running with a commercial 20 wt% Pt/C. The excellent electrocatalytic properties are primarily by virtue of the highly specific surface area and porosity of carbon support, uniformly dispersed Ru active species, and rapid reaction kinetics of the interaction between Ru and O.

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In this paper, a facile route has been developed to prepare magnetic trimetallic Au-Ag-γ-Fe2O3/rGO nanocomposites. The impact of the preparation method (the intensity of reductant) on the catalytic performance was investigated. The nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The prepared nanocomposites show fine catalytic activity towards the reduction reaction of 4-nitrophenol (4-NP). The nanocomposites also have superparamagnetism at room temperature, which can be easily separated from the reaction systems by applying an external magnetic field.

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