Nickel–iron based materials are well-known catalysts for the oxygen evolution reaction (OER) and have been widely investigated. However, the synergy between these two components is still controversial. Herein, we report a facile immersion method for the synthesis of binder-free nickel–iron hydroxide loaded on Ni foam (NiFe-OH/NF) with superior hydrophilic property and high OER catalytic activity. The strong hydrophilic property of the binder-free NiFe-OH/NF electrode significantly enhances an effective contact between electrocatalyst and aqueous electrolyte and favors the bubble detachment from the electrode, facilitating the electron transfer and improving the OER activity. The hydrophilic NiFe-OH/NF can achieve a geometrical current density of 100 mA cm–1 at an extremely low overpotential (219 mV), along with a Tafel slope of 56 mV dec–1 and superior long-term stability at high current density in alkaline media, strongly indicating that the hydrophilicity plays an important role in improving the OER performance in the NiFe-OH/NF.

Polycrystalline alloy electrodes of Pt with alkaline earth metals (Ca, Sr, and Ba) have been shown to exhibit enhanced electrocatalytic performance for oxygen reduction reaction (ORR) relative to Pt electrodes. The large oxophilicity of the alkaline earth metals makes it challenging to synthesize such alloys. Here, we synthesize a carbon-supported platinum−magnesium (PtMg) alloy with enhanced catalytic activity and durability for the ORR in both a half-cell and single cell when compared to the state-of-the-art Pt/C catalyst. Employing metallic Mg powder as a precursor can overcome the large oxophilicity of Mg and induce alloying of Mg with Pt, whereas conventional Mg salts do not form an alloy. Density functional theory calculations elucidate the origin of the enhanced catalytic activity and durability. Complementary physical and electrochemical analyses also evidence them in this work. This material holds great application potential and will contribute to elucidation of the effects of alloying Pt with electropositive metals.

The amount of Fe and NH3 treatment significantly affect the structural and catalytic properties of resulting ZIF-derived Fe–N–C catalysts.

In this study, monodisperse polystyrene nanospheres were prepared by dispersion polymerization using alcohol as reaction medium to prepare colloidal clusters of the latex beads. Polyvinylpyrrolidone (PVP) and 2-(methacryloyloxy)ethyltrimethylammonium chloride (MTC) were used as dispersion stabilizer and comonomer, respectively. The particle size could be controlled by adjusting the reactant compositions such as the amount of stabilizer, comonomer, and water in the reactant mixture. The size and monodispersity of the polymeric particles could be also controlled by changing the reaction medium with different alcohols other than ethanol or adjusting the polymerization temperature. The synthesized particles could be self-organized inside water-in-oil emulsion droplets by evaporation-driven self-assembly to produce colloidal clusters of the polymeric nanospheres.