| Copper-based nanomaterials as one kind of important transition metal oxidesnanomaterials, has potential applications in gas sensor, catalyst, lithium ion batteryand the heavy metal adsorption and so on. Compared with other transition metaloxides, the copper-based nanomaterials are cheap, environmentally friendly, and highcatalytic activity thus much attention has paid to synthesize well-definedcopper-based nanomaterials. In recent years, many efforts have been made to preparedifferent shape and size of the copper-based nanomaterials, and also researched invarious areas of the application in the future. Previous studies indicated that thedevelopment of different methods to control the morphologies, size, composition,surface area of nanomaterials can improve material in various aspects of performance.At the same time, the growth mechanisms responsible for the formation ofcopper-based nanostructures in order to control the growth of nanomaterials are alsoindispensable. And for the fundamental theoretical research of the application in thecatalytic, gas sensor, photocatalytic properties are still a major challenge. In this paper,we focused on the application of copper-based nanomaterials in catalytic, adsorptionand gas sensor. Firstly, CuO nanorods were synthesized by microwave hydrothermalmethod, and the catalytic performance were also studied. Secondly, the sheet-likeCuO precursor was prepared using the thermal precipitation method. Then we havereported the structural, adsorption and photocatalytic properties of copper oxidenanomaterials synthesized by microwave hydrothermal recrystallization at differentpH values. Furthermore, Cu-Cu2O-C composite was prepared by a simple heatingprocedure using metal-oleate complex as the precursors，the CuO nanomaterials werealso obtained by calcination the composites. And the photocatalytic and gas sensorperformance were also studied. The details were as follows:Firstly, CuO nanorods have been prepared through a facilemicrowave-hydrothermal method with the aid of polyethylene glycol400, ethylene glycol and urea. The X-ray diffraction and transmission electron microscopy resultsshowed that the prepared CuO nanocrystalline had a rod-like shape with diameters of15-20nm and the average length of80nm. Compared with commercial CuO powder,the CuO nanorods showed an enhanced catalytic activity for the synthesis of sodiumhumate and degradation of Rhodamine B. The yield of sodium humate catalyzed byCuO nanorods was75.78%, which was higher than that of the commercial CuOpowder (52.8%). In addition, the CuO nanorods showed a relatively faster degradationrate of RhB. The CuO nanorods prepared by this facile method demonstrated theirpotential applications in the field of catalysis.Secondly, we reported the structural, adsorption and photocatalytic properties ofcopper oxide nanomaterials synthesized by microwave hydrothermal recrystallizationat different pH values. The synthesized products were characterized by X-raydiffraction (XRD), transmission electron microscopy (TEM), Fourier transforminfrared (FTIR) and specific surface area measurements. These results revealed thepure phase of CuO with mesoporous structures and the morphology of samplessynthesized at different pH values change from nanosheets to rectangular nanorods. Apossible mechanism for the growth of CuO nanostructures has also been described.The as-synthesized CuO nanosheets at pH=11exhibited the best adsorptionperformance and photocatalytic activity. The maximum adsorption capacity foradsorption of Congo red (CR) on the CuO nanosheets (pH=11) was256mg g-1, andalso had enhanced photocatalytic performance with99.5%decomposition ofRhodamine B (RhB) after50min. The enhanced adsorption and photocatalytic performance may be attributed to its relatively large specific surface area.Furthermore, the Cu-Cu2O-C composite was synthesized by pyrolysis ofmetal-oleate, and the CuO nanomaterials were also obtained by calcination thecomposites. The as-synthesized products were characterized by X-ray diffraction,transmission electron microscopy and energy dispersive X-ray spectrum. As can beseen from the XRD patterns, the diffraction peaks of Cu2O became strong and sharpwith the dosage of KOH increased. In contrast, the diffraction peak of Cu wasobviously when without added KOH. At the same time, the size of the nanopaticlesincreases with increasing the calcination temperature. The photocatalytic performanceof the series of as-prepared products was carried out by the degradation of the methylorange. The results indicated that the molar ratio of the cupric salt with alkali was1:2.5, and the calcination temperature was400oC, the photocatalytic performancewas superior to the others. The as-prepared products showed an enhancedphotocatalytic performance with97.3%degradation of MO after3h reaction underUV light irradiation, which was much higher than the others. We also studied the gassensor properties of the CuO nanomaterials. The experimental results show that theproducts have a high response to ethanol and acetone. |
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