Cuprous Oxide Of Micro-nano Structures: Preparation And Characterization

Cuprous oxide is a direct band gapⅡ-Ⅵsemiconductor material with band gap of about 2.0-2.2 eV. Because of its photoelectric conversion characteristics and photocatalytic performance advantages, cuprous oxide has become a focus in the field of materials science and industrial production. The main objects of this thesis is to synthesize cuprous oxide micro-nanoparticles with different morphologies by hydrothermal and solvothermal methods,which were widely used in synthesis of cuprous oxide semiconductior materials because of their simple device, easy operation, low cost and controllability in product morphology.(1) Cuprous oxide crystal was synthesized by hydrothermal method from copper acetate, de-ionized water, and triethanolamine. The effects of reaction conditions, including reaction time, reaction temperature, molar ratios, and surfactant cetyltrimethylammonium bromide (CTAB), on the morphology of cuprous oxide crystals were investigated. The SEM and XRD results show that the octahedral structure of cuprous oxide crystals was obtained by hydrothermal method, with the optimum conditions:0.2 g copper acetate,7.5 ml triethanolamine and 15 ml deionized water; temperature:160℃; reaction time: 70min..(2) Different morphologies of micron-nanostructures cuprous oxide were synthesized by solvothermal method from copper acetate, triethanolamine and organic alcohol (ethanol, ethylene glycol and glycerin). Different reaction conditions, inculding reducing agent, reaction temperature, reaction time, solvent, raw material ratio, and surfactant cetyltrimethylammonium bromide (CTAB) or hexamethylenetetramine, were investigated with respect to their effects on the micro-nano structures of cuprous oxide. The morphologies and crystal structure were characteried by SEM and XRD. The results show that the optimum preparation conditions of cuprous oxide microspheres were:reaction temperature 160℃, ethylene glycol 20 ml, copper acetate 0.6 g, triethanolamine 6.5 ml, CTAB was 0.2 g, and reaction time 70 min.. The prepared cuprous oxide microspheres was regular in morphology, with a narrow dispersion of the particle size in about 1-3 microns. When the amount of CTAB was set at 0.1g and ethylene glycol or glycerol was used as reducing agent,cuprous oxide cube was obtained. When surfactant was changed from CTAB to hexamethylenetetraomine, and ethylene glycol was used as solvent and reducing agent, hollow nanospheres of cuprous oxide was obtained. From above results,the growth mechanism of micro or nanostructured cuprous oxide and the role of alcohol in the formation of the structures were discussed.