Synthesis of CuO Nanorods, Reduction of CuO into Cu Nanorods, and Diffuse Reflectance Measurements of CuO and Cu Nanomaterials in the Near Infrared Region
ABSTRACT CuO nanorods were synthesized by hydrothermal methods with three different chemical combinations: (i) copper nitrate, lactic acid, and sodium hydroxide; (ii) copper sulfate, sodium lactate, and sodium hydroxide; and (iii) copper nitrate and sodium hydroxide. Physical parameters, concentration, temperature, and aging time, greatly affected the size and morphology of the nanorods; CuO nanoparticles were also prepared. These nanorods and nanoparticles were reduced to metallic copper at elevated temperature by 4% H2 diluted in helium. The morphology of CuO nanomaterials (nanorods and nanoparticles) was preserved after reduction. These CuO and Cu nanorods and nanoparticles were characterized by XRD, SEM, TEM, SEM-EDS, and BET measurements. The CuO and Cu nanomaterials were employed for near-infrared (NIR) diffuse reflectance. Among these materials, CuO nanorods were to be found the best NIR diffuse reflectors, indicating potential application as NIR obscurants.
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ABSTRACT: Designed octahedral Cu nanocages were successfully prepared at room temperature by introducing Ni induced electroless strategy. This strategy balanced the inhibitory effect of sodium oleate (SOA) in the room temperature reduction process. Reduction rate was markedly improved as Ni2+ increasing. The Ni-induced electroless Cu deposition mechanism was studied. The first deposited metallic Ni particles catalyzed the oxidation of hydrazine (N2H4·H2O) to give electrons. Cu2O intermediates captured the electrons and were reduced to Cu nanocages with SOA existence. Thermo-gravimetric and differential thermal analysis (TG–DTA) results illuminated that the Ni-induced Cu nanocages had higher oxidation resistance property in air atmosphere compared to Cu nanocages prepared without Ni inclusion. A well-defined, stable and fast amperometric response of glucose was observed when the Ni-induced Cu nanocages were constructed as non-enzymatic glucose sensor.Colloids and Surfaces A Physicochemical and Engineering Aspects 08/2013; 431:60–65. DOI:10.1016/j.colsurfa.2013.04.019 · 2.35 Impact Factor
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ABSTRACT: Typical surfactants, cetyltrimethylammonium bromide (CTAB), poly(vinyl pyrrolidone) (PVP) and sodium oleate (SOA), were employed to investigate their effect on fabricating CuO nanoleaves and Cu nanocages at room temperature. Comparing with the system without surfactant, adding surfactant could improve the monodispersity of CuO nanoleaves. The obtained CuO nanoleaves were further reduced to Cu nanocages. CTAB performed few effects on the reduction process. PVP accelerated the reducing velocity, while SOA had inhibitory effect on the reaction. The reaction activities of the obtained Cu nanocages with and without surfactants were characterized by thermo-gravimetric and differential thermal analysis (TG–DTA), and the sequence of activity with oxygen is PVP-assisted Cu > SOA-assisted Cu > CTAB-assisted Cu > Cu without surfactant. The obtained Cu nanocages were also used to construct non-enzymatic glucose sensors. The electrodes modified by PVP- and SOA-assisted Cu had relative higher sensitivity than the others.Colloids and Surfaces A Physicochemical and Engineering Aspects 09/2013; 436. DOI:10.1016/j.colsurfa.2013.05.079 · 2.35 Impact Factor