Uniform CeO(2) nanoflowers were synthesized by rapid thermolysis of (NH(4))(2)Ce(NO(3))(6) in oleic acid (OA)/oleylamine (OM), by a unique 3D oriented-attachment mechanism. CeO(2) nanoflowers with controlled shape (cubic, four-petaled, and starlike) and tunable size (10-40 nm) were obtained by adjusting the reaction conditions including solvent composition, precursor concentration, reaction temperature, and reaction time. The nanoflower growth mechanism was investigated by in situ electrical conductance measurements, transmission electron microscopy, and UV/Vis spectroscopy. The CeO(2) nanoflowers are likely formed in two major steps, that is, initial formation of ceria cluster particles capped with various ligands (e.g., OA, OM, and NO(3) (-)) via hydrolysis of (NH(4))(2)Ce(NO(3))(6) at temperatures in the range 140-220 degrees C, and subsequent spontaneous organization of the primary particles into nanoflowers by 3D oriented attachment, due to a rapid decrease in surface ligand coverage caused by sudden decomposition of the precursor at temperatures above 220 degrees C in a strong redox reaction. After calcination at 400 degrees C for 4 h the 33.8 nm CeO(2) nanoflowers have a specific surface area as large as 156 m(2) g(-1) with high porosity, and they are highly active for conversion of CO to CO(2) in the low temperature range of 200-400 degrees C. The present approach has also been extended to the preparation of other transition metal oxide (CoO, NiO, and CuO(x)) nanoflowers.
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http://dx.doi.org/10.1002/chem.200701348 | DOI Listing |
Anal Chim Acta
January 2025
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, 130000, PR China. Electronic address:
Nitrite is widely used as a food additive, and it is of great significance to realize accurate detection of nitrite for food safety. Electrochemical technique is characterized by simple operation and portability, which enables rapid and accurate detection. The key factors affecting the nitrite detection performance are the electrocatalytic activity and interfacial electron transfer efficiency of the electrode.
View Article and Find Full Text PDFEnviron Res
July 2024
Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
The cube architecture associated with the CeO nanoflowers (NFs) that generated, which had an average crystallization width of 7 nm, has been confirmed by X-ray crystallographic investigations. The method used is environmentally acceptable since it converts wasted banana peel extracts into CeO nanoflower. On the basis of artwork obtained from a High-Resolution Transmission Electron Microscope (HR-TEM), CeO nanoparticles have been observed to possess a spherical shape and an average particle diameter of 21 nm.
View Article and Find Full Text PDFACS Omega
April 2023
Advanced Materials Group, Materials Sciences and Technology Division, CSIR-North East Institute of Science and Technology, Jorhat 785006, Assam, India.
Molecules
July 2022
Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
CeO nanoparticle-loaded MnO nanoflowers, prepared by a hydrothermal method followed by an adsorption-calcination technique, were utilized for selective catalytic reduction (SCR) of NO with NH at low temperatures. The effects of Ce/Mn ratio and thermal calcination temperature on the NH-SCR activity of the CeO-MnO nanocomposites were studied comprehensively. The as-prepared CeO-MnO catalysts show high NO reduction efficiency in the temperature range of 150-300 °C, with a complete NO conversion at 200 °C for the optimal sample.
View Article and Find Full Text PDFBioelectrochemistry
August 2022
Key Laboratory of Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China. Electronic address:
Currently, developing an effective and easy-to-operate signal amplification assay to detect the trace-amount miRNAs in serum remains a significant challenge. Herein, an ultrasensitive CeO@Ag hybrid nanoflower (CeO@Ag HNF)-labeled electrochemical biosensor was developed for sensing miRNA, based on a target-feedback rolling-cleavage (TFRC) signal amplifier. CeO@Ag HNFs possessing a unique three-dimensional layered structure were synthesized without any complex reaction conditions, such as heating and vacuum.
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