An Fe-V@NiO heterostructure electrocatalyst towards the oxygen evolution reaction.

The development of a nonprecious and Earth-abundant electrocatalyst with high electrocatalytic activity for the oxygen evolution reaction (OER) is an emerging hot issue and remains a grand challenge. In the present work, we proposed a facile strategy to construct ultrathin NiO nanosheets decorated with Fe-V nanoparticles on nickel foam (Fe-V@NiO/NF) for use as an OER electrocatalyst. Due to the 3D rational configuration, the Fe-V@NiO/NF with a heterostructure shows excellent electrocatalytic activity towards the OER. Interestingly, it is found that in situ oxidation by galvanostatic electrolysis in alkaline solution is beneficial to enhance the OER performance. After 10 h of electrolysis, a current density of 50 mA cm-2 is achieved at a low overpotential of 271.1 mV. This is because during the in situ oxidation process, iron and vanadium ions insert into the NiO lattice and lead to the generation of highly active α-FeOOH and an amorphous (oxy)-hydroxide layer. Additionally, the charge transfer resistance dramatically reduces with the prolonging of oxidation time.

Highly porous copper ferrite foam: A promising adsorbent for efficient removal of As(III) and As(V) from water.

A novel copper ferrite foam fabricated on Fe-Ni foam substrate was synthesized via a simple hydrothermal method to efficiently remove arsenic from aqueous solution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-Ray diffraction pattern (XRD) and Raman spectra were used to characterize the morphology and surface composition of the copper ferrite foam (CFF). The adsorption behavior of As(III) and As(V) onto this CFF is studied as a function of solution pH, temperature, contact time, and different concentrations. Results shown that this CFF has high adsorption capacity and excellent recyclability. Adsorption isotherms study indicates Langmuir model of adsorption. The maximum adsorption capability of As(III) and As(V) on CuFe2O4 foam is observed about 44.0 mg g-1 and 85.4 mg g-1, respectively. Regeneration experiment indicates that arsenic could be easily desorbed from CFF with 0.10 mol L-1 NaOH and the high adsorption capacity can be maintained for six regeneration cycle.