Metal organic framework-combustion: A one-pot strategy to NiO nanoparticles with excellent anode properties for lithium ion batteries

NiO nanoparticles with average particles size of 30 nm are synthesized using a one-pot metal–organic framework-combustion（MOF-C） technique, for use as an anode material in rechargeable lithium ion batteries（LIBs）. The structural and electronic properties of these nanoparticles are studied using various techniques, including powder X-ray diffraction（PXRD）, transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, X-ray photoelectron spectroscopy（XPS）, and N_2 adsorption/desorption studies. The as-synthesized NiO nanoparticles sustained reversible stable capacities of 748 and 410 mAh/g at applied current densities of 500 and 1000 m A/g, respectively, after 100 cycles. Furthermore, the anode displays a notable rate capability, achieving a stable capacity of ~200 mAh/g at a high current density of10 A/g. These results indicate that the size of the NiO nanoparticles and their high surface area influence their electrochemical properties. Specifically, this combustion strategy is clearly favorable for improving the cyclability and rate capability of various metal oxides in rechargeable battery electrodes.

Facile Synthesis of Rose-Like NiO Nanoparticles and Their Ethanol Gas-Sensing Property

In this study, rose-like nickel oxide （NiO） nanoparticles with diameters of 400-500 nm are prepared on ITO glass substrates by simple electrodeposition in NiSO46H20 solution at room temperature followed by oxidation in air. Scanning electron microscopy, x-ray diffraction and a transmission electron microscope are used for analyses of the NiO nanoparticles. The ethanol gas sensitivity of these nanoparticles is studied. The results indicate that the rose-like NiO nanoparticles could be used for the fabrication of ethanol gas sensors to monitor the low concentration of ethanol gas in air. Furthermore, at 5 ppm, the NiO nanorose-based sensors show a high response to ethanol （Rg/Ra = 8.4）.

3DRGO-NiFe2O4/NiO nanoparticles for fast and simple detection of organophosphorus pesticides

The residues of organophosphorus pesticide(OPs)on fruits and vegetables pose a threat to human health,so it is very meaningful to explore simple and fast detect methods for OPs residual.In this work,nickel ferrite/nickel oxide nanoparticles co-loaded three-dimensional reduced graphene oxide(3DRGONiFe2O4/NiO NPs),as a new low cost nanocomposite,was prepared.Based on its high performance mimetic peroxidase activity,a colorimetric method for the detection of OPs has been developed.Dichlorvos was chosen as model compounds to evaluate the detection performance.The detection linear range for dichlorvos is from 50μg/mL to 2.5×10^4μg/mL with a detection limit of 10μg/mL.Furthermore,a test paper can be developed based on the 3 DRGO-NiFe2O4/NiO NPs for visual detection of dichlorvos,and the image information of the paper sensor can be converted into digital signal and quantitative detection by a smartphone.Notably,this method can also be used to detect dichlorvos in real samples,including vegetables and fruits.Thus,the developed naked assay holds great potential in simple,inexpensive and rapid detection of OPs in fruit and vegetable samples.

Rambutan-like hollow carbon spheres decorated with vacancy-rich nickel oxide for energy conversion and storage

Transition metal oxides hold great promise for lithium-ion batteries(LIBs)and electrocatalytic water splitting because of their high abundance and high energy density.However,designing and fabrication of efficient,stable,high power density electrode materials are challenging.Herein,we report rambutan-like hollow carbon spheres formed by carbon nanosheet decorated with nickel oxide(NiO)rich inmetal vacancies(denoted as h-NiO/C)as a bifunctional electrode material for LIBs and electrocatalytic oxygen evolution reaction(OER).When being used as the anode of LIBs,the h-NiO/C electrode shows a large initial capacity of 885mAh g−1,a robust stability with a high capacity of 817mAh g−1 after 400 cycles,and great rate capability with a high reversible capacity of 523mAh g−1 at 10Ag−1 after 600 cycles.Moreover,working as an OER electrocatalyst,the h-NiO/C electrode shows a small overpotential of 260mV at 10mAcm−2,a Tafel slope of 37.6mVdec−1 along with good stability.Our work offers a cost-effective method for the fabrication of efficient electrode for LIBs and OER.