The Controllable Preparation Of Nano Cuprous Oxide Octahedron, Growth Mechanism And The Study Of Optical Properties

Cuprous oxide (CU2O) is an inexpensive and environment friendly p-type semiconductor with a direct band-gap of2.17eV, and CU2O has potential applications in industry and agriculture, such as pigment, photocatalyst, preservative, antifouling coat, photoelectric material and ballast. As a material for photoelectric conversion, the CU2O films have been widely used in solar cells and other fields. At the same time, the CU2O has also been utilized in sensors and high-temperature superconductors. Recently, the research hot spots are how to synthesize CU2O nanocrystals with controlled-morphology and size.In this paper, nanoscale CU2O octahedra have been synthesized on aluminum substrates by potentiostatic/electrodeless deposition under the basic conditions, in which the CUSO4is the root, and lactic acid is the complexant. The morphology and microstructure were carried out by scanning electron microscopy (SEM), transition electron microscopy (TEM) and high-resolution transition electron microscopy (HRTEM) in detail.The effect of different experiment conditions (such as electric potential, pH, mole ratio of lactic acid to Cu2+ions, temperature and reaction time) on the morphology and size of the CU2O nanocrystals also was studied. It suggested that all the experimental parameters (-0.45-0V,20℃-80℃and R=0.75/0.4-6/0.4) have distinct effect on the size of the nanocrystals, but when the potential was more negative than-0.5V, the morphology changed from particles to films. However, the morphology of the crystals were compact films when the substrates were irons and copper foils. All the specimens deposited under different conditions were cuprous oxide, but no CuO or Cu formed. The results analysis of UV-visible absorption spectroscopy indicated that the light absorption of the nano-particles has a blue shit as the particle size reduced.Based on our experimental results, the growth mechanism of CU2O octahedra was explained by electric double layer. Then the effect of different experiment conditions on the morphology and size of the nanocrystals was interpreted by the growth mechanism.