Narrow Results

In the International Space Station, urine is considered something to be treated. However, urine is mainly composed of water and urea, while they have been demonstrated as an excellent hydrogen carrier for sustainable energy supply. Through the simple chemical coprecipitation and hydrothermal reaction, the needle-like NiMoO₄ crystals were synthesized with the average width around 500nm and length up to 4$\mu$m. The resulted products were thoroughly characterized by scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction, Fourier-transform infrared spectroscopy and ultraviolet–visible spectrum. The needle-like NiMoO₄ crystals exhibited excellent electrocatalytic oxidation toward urea at anode in alkali solution, leading to the increased performance of hydrogen evolution reaction at cathode with the lower electrochemical potential and energy consumption required to drive the reaction. The high electrocatalysis of the needle-like NiMoO₄ crystals toward urea oxidation reveals their great potential for future application to clean the urine/urea-rich wastewater and to produce hydrogen in space station and environmental wastewater.

Electrodes of rationally designed composite nanostructures can offer many opportunities for the enhanced performance in electrochemical energy storage. This paper attempts to illustrate the design and production of NiMoO₄/polypyrrole core–shell nanostructures on nickel foam to be used in supercapacitor via a facile hydrothermal and electrodeposition process. It has been verified that this novel nanoscale morphology has outstanding capacitive performances. While employed as electrodes in supercapacitors, the composite nanostructures showed remarkable electrochemical performances with a great areal capacitance (3.2F/cm² at a current density of 5mA/cm²), and a significant cycle stability (80% capacitance retention after 1000 cycles). The above results reveal that the composite nanostructures may be a likely electrode material for high-performance electrochemical capacitors.