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.
- SourceAvailable from: Arulraj Arulkashmir[Show abstract] [Hide abstract]
ABSTRACT: A single step protocol to prepare Cu2O and CuO nanocrystalline particles from the same precursor by microwave irradiation has been developed using the pH of the solution as the only variable parameter. The utility of different bivalent Cu-precursor for synthesis of CuO and Cu2O nanoparticles was also investigated. The morphology, phase purity and optical properties of these nanoparticles were analyzed using TEM, SEM, XRD and optical spectroscopy. The band edges were determined using cyclic voltammetry. Field effect transistors based on CuO nanoparticles showed a hole mobility of 3.5×10-2 cm2 V-1 s-1, making them a suitable candidate for energy related applications. The effect of hydrazine vapor exposure on CuO nanoparticles was also investigated. This revealed a decrease in source current with respect to timeCrystal Growth & Design 07/2014; · 4.56 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: We develop a simple strategy for the collection of oil spill using a miniature device. The device was enfolded from a sheet of copper mesh with surface superhydrophobicity and superoleophilicity. The copper mesh was fabricated through a simple thermal oxidation and surface modification process. The miniature device adsorbed various oils from the surface of oil–water mixture in its pores while repelling water completely. After the pores were full of oil, only oil could infiltrate into the device through the pores automatically and was finally concentrated into the device, showing its oil–water separating ability. Importantly, the concentrated oil in the device could be taken away by a dropper or pumped out, thus achieving the collection of oil for reuse. Additionally, after the concentrated oil was taken away, the device could be used in the next oil–water separating cycle without apparent decrease of its separation ability. Therefore, the findings in this work may offer a new strategy for the collection and reuse of various kinds of oils and other organic compounds from water surfaces.The Journal of Physical Chemistry C 03/2014; 118(12):6344–6351. · 4.84 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: We report the nitrogen monoxide (NO) gas sensing properties of p-type CuO-nanorod-based gas sensors. We synthesized the p-type CuO nanorods with breadth of about 30 nm and length of about 330 nm by a hydrothermal method using an as-deposited CuO seed layer prepared on a substrate by the sputtering method. We fabricated polycrystalline CuO nanorod arrays at under the hydrothermal condition of 1:1 morality ratio between copper nitrate trihydrate  and hexamethylenetetramine (). Structural characterizations revealed that we prepared the pure CuO nanorod array of a monoclinic crystalline structure without any obvious formation of secondary phase. It was found from the gas sensing measurements that the p-type CuO nanorod gas sensors exhibited a maximum sensitivity to NO gas in dry air at an operating temperature as low as . We also found that these CuO nanorod gas sensors showed reversible and reliable electrical response to NO gas at a range of operating temperatures. These results would indicate some potential applications of the p-type semiconductor CuO nanorods as promising sensing materials for gas sensors, including various types of p-n junction gas sensors.Korean Journal of Materials Research 01/2014; 24(1).