Ultrasonic-assisted Fenton reaction inducing surface reconstruction endows nickel/iron-layered double hydroxide with efficient water and organics electrooxidation.

Nickel/iron-layered double hydroxide (NiFe-LDH) tends to undergo an electrochemically induced surface reconstruction during the water oxidation in alkaline, which will consume excess electric energy to overcome the reconstruction thermodynamic barrier. In the present work, a novel ultrasonic wave-assisted Fenton reaction strategy is employed to synthesize the surface reconstructed NiFe-LDH nanosheets cultivated directly on Ni foam (NiFe-LDH/NF-W). Morphological and structural characterizations reveal that the low-spin states of Ni (te) and Fe (te) on the NiFe-LDH surface partially transform into high-spin states of Ni (te) and Fe (te) and formation of the highly active species of NiFeOOH.

Iron and nitrogen co-modified multi-walled carbon nanotubes for efficient electrocatalytic oxygen reduction.

Multi-walled carbon nanotubes (MWCNTs) with one-dimensional nanostructure are an ideal support for oxygen reduction reaction (ORR) catalysts thanks to their intrinsic outstanding electrical conductivity and high specific surface area. Iron and nitrogen doping could alter the local electronic structure and therefore enhance the ORR activity of MWCNTs, but the preparation process always includes complicated growth conditions and post-treatment. Herein, an iron and nitrogen co-modified multi-walled carbon nanotubes (Fe-N-MWCNTs) with hierarchical nanostructure is engineered and synthesized via a simple two-step pyrolysis approach.

Highly sensitive detection of Pb and Cu based on ZIF-67/MWCNT/Nafion-modified glassy carbon electrode.

A series of different facile modification layers (MLs) was designed to gradually increase the electrochemical sensing performance of glassy carbon electrode (GCE) for simultaneously detecting Pb and Cu. ML designs were mainly a different combination of ZIF-67, MWCNT and Nafion, and their different electrochemical sensing performances were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), square wave stripping voltammetry (SWSV) and chronocoulometry. The fabricated sensor, which modified with ZIF-67/MWCNT and Nafion layer, exhibited the biggest response peak current to Pb and Cu.

Insight into the effect of the continuous testing and aging on the SO sensing characteristics of a YSZ (Yttria-stabilized Zirconia)-based sensor utilizing ZnGaO and Pt electrodes.

In this paper, YSZ-based mixed potential SO sensor with ZnGaO and Pt electrodes was developed and the effect of the continuous testing and aging process on the sensing characteristics was discussed. The results showed that with this process the response of the sensor to SO performed an opposite direction to that in the sensor's initial state. The reason might be that the PtS produced at the Pt electrode increased the electrochemical catalytic activity of the Pt electrode, leading to the mixed potential of the Pt electrode higher than that of the ZnGaO electrode.

Fabrication of Well-Ordered Three-Phase Boundary with Nanostructure Pore Array for Mixed Potential-Type Zirconia-Based NO2 Sensor.

A well-ordered porous three-phase boundary (TPB) was prepared with a polystyrene sphere as template and examined to improve the sensitivity of yttria-stabilized zirconia (YSZ)-based mixed-potential-type NO2 sensor due to the increase of the electrochemical reaction active sites. The shape of pore array on the YSZ substrate surface can be controlled through changing the concentration of the precursor solution (Zr(4+)/Y(3+) = 23 mol/L/4 mol/L) and treatment conditions. An ordered hemispherical array was obtained when CZr(4+) = 0.