Preparation Of CuO And CuO/Ag NaNo Materials And Their Photocatalytic Property

Cuprous oxide (CuO) is a kind of p-type narrow band gap semiconductor material. The band gap is 1.2-1.8eV. Because of its good absorption in the visible light, it has been widely used in the field of photocatalysis, solar cell and so on. Due to the high recombination rate of electron and hole generated by CuO semiconductor in the light, the photocatalytic efficiency is low. Due to the high recombination rate of electron and hole in the light generated by CuO semiconductor, the photocatalytic efficiency is low. In this paper, we mainly study the preparation of CuO nano materials and CuO/Ag composite materials on the Cu substrate, and study the influence of preparation conditions on the structure, morphology and photocatalytic properties of CuO and CuO/Ag composite nanomaterials. The content of this paper mainly includes the following contents:1. A simple wet chemical method was used to synthesize the flower-like CuO nano materials on the Cu substrate. The effects of sodium thiosulfate (Na2S2O3) concentration and NaOH concentration on the structure, morphology and photocatalytic properties of CuO nano materials were studied. A preliminary study on the mechanism of flower-like CuO nano materials prepared by the simple wet chemical method was carried out. Experiments show that:when the concentration of Na2S2O3 is greater than 0.4 mol/L, the flower-like CuO nano materials can be prepared on Cu substrate; when the concentration of NaOH is 2.5 mol/L, the flower-like CuO nano materials can be prepared on Cu substrate. When the concentration of NaOH is relatively low (<1 mol/L), honeycomb structure CuO nano materials can be prepared. When the concentration of NaOH is relatively high(>3.5 mol/L), CuO nanowires and nanoplates composites were prepared. The photocatalysis performance of flower-like CuO nano materials was significantly higher than that of the non flower-like CuO nano materials. The flower-like CuO nano materials have good light stability.2. Using polyethylene glycol (PEG 400, Mw=400) as surface active agent and reducing agent, metallic silver were deposited on the surface of the flower-like CuO nano materials to prepare CuO/Ag composite nano materials by photochemical deposition method. The influence of the AgN03 concentration and photochemical deposition time on the structure, morphology and optical the catalytic performance of CuO/Ag composite nano materials were studied, and the photochemical deposition mechanism of CuO/Ag composite nano materials was explored. Experiments show that:with the increase of the concentration of AgNO3, the volume of Ag particles by photochemical deposition increased first, then decreased and formed uniform small particles covered on the CuO nanowire surface. With the increase of the concentration of AgNO3, the photocatalytic degradation efficiency of CuO/Ag composite nano materials first increased and then decreased. The photocatalytic degradation efficiency of MO prepared with 6mmol/L AgNO3 is the highest, reaching 98.7%. When photochemical deposition reaction was 2h, Ag nanoparticles would appear on the surface of CuO nanowire. With the prolonging of reaction time, the volume of the Ag nanoparticles by photochemical deposition increases, the photocatalytic efficiency of CuO/Ag nano composites increased gradually3. Flower-like CuO nano materials composed of nano sheets were prepared by hydrothermal method on Cu substrate. The effects of reaction temperature, time, the content of NaOH and PEG4000 on the structure, morphology and photocatalytic properties of CuO nano materials were studied. And the preparation mechanism of CuO nano materials by hydrothermal method was explored. Experimental results show:with the increase of NaOH content, the nano flower diameter of the CuO and the photocatalytic efficiency improve; with the increase of the reaction temperature, the number of CuO nano flowers increased and the thickness of the CuO nanosheets gradually increased. With the increase of the reaction temperature, the photocatalytic efficiency of samples increased first and then decreased. When the reaction temperature is 100 ℃, the photocatalytic efficiency of the samples reached the maximum. With the increase of reaction time, the photocatalytic efficiency of samples improve. With the increase of PEG4000 content, the content of nano CuO generated in the substrate of Cu reduced. The photocatalytic efficiency of the prepared samples also reduced. The addition of PEG4000 is not conducive to the preparation of nanometer CuO.