【作者】 李晓勤；

【导师】 李家麟；

【作者基本信息】 华中师范大学 ， 分析化学， 2006， 硕士

【摘要】 氧化亚铜（Cu₂O）是一种重要的新型无机功能材料,能带宽为2.0eV,比TiO₂的3.2eV低得多,可被600nm的光激发,完全可在太阳光的辐射下引发光催化反应。而且大量的实验表明,多晶态的Cu₂O不像单晶Cu₂O,可反复使用而不会被还原成Cu（0）或是氧化成Cu（Ⅱ）,稳定性很好。1998年,Ikeda等人首次宣布用Cu₂O作光催化剂可在太阳光下将水分解成氢气和氧气。这些事实都预示着Cu₂O在可见光下具有良好的催化性能。块体Cu₂O量子效率较低,产生的光生电子—空穴对易复合。当粒度小到纳米级时,复合率降低,可提高量子产率。因此,制备纳米级的Cu₂O可提高其光催化性能。 本论文工作主要是研究电解法制备纳米氧化亚铜的反应条件以及控制条件制备出不同形貌的纳米氧化亚铜,并讨论了纳米级氧化亚铜的光催化活性。首先用表面活性剂十六烷基三甲基溴化氨作软模板,用电解法制备纳米氧化亚铜,用TEM、SEM、HRTEM、XRD、XPS来表征制备的样品,并确定了最佳的制备工艺条件:阳极电解液中氯化钠浓度为300g/l,CTAB的浓度为0.15g/l;阴极液中氢氧化钠浓度为1mol/l。当以上条件不变时,电解电流为0.3A,电解时间为20分钟,制备出的纳米氧化亚铜结构为六角、四角星状以及八面体的纳米颗粒,且颗粒上有许多小孔;当电解电流为0.1A时,电解时间为20min制备出了纳米晶须,电解时间为5min时在铜板上镀上了一层定向生长、排列整齐、分布均匀的纳米晶须。并探讨了几种不同形貌的纳米氧化亚铜的生长机理。 将所制备出的纳米氧化亚铜作为光催化剂降解活性艳红X-3B,25mg催化剂在60min内即可使100mg/l的活性艳红溶液的降解率达到96.64%。同时,还用该催化剂降解甲醛,发现其可以将甲醛降解完全。更多还原

【Abstract】 Nano-size Cuprous（Cu₂O）oxide is a kind of important inorganic material. It has a direct forbidden band gap of about 2.0 eV which is lower than TiO₂ and it can be excitated with light of 600nm .Therefore, with radicalization of visible light it can happen photocatalytic reaction. Most experiments shows that mutli-crystals not like single crystal are stabile which can be used for many times and not reduced to Cu（0） or oxidated to Cu（II）. In 1998, Ikeda et al firstly showed that Gu₂O could decompose H₂O to H₂ and O₂ in the sunlight. It predicted that Cu₂O may be employed as a promising catalyst under visible light. As we know that the quantum efficiency of bulk Cu₂O is quite low , so the electron -cavity of sunlight excitation is easy to recombine. The quantum efficiency can be greatly improved while the scale of Cu₂O transform from micrometer to nanoscale. Therefore, preparation of nano-size Cu₂O is important for improving its photocatalytic characterization.In our study, we main tried to prepare nano-size Cu₂O with a novel electrochemical method and controll reactive conditions to prepare different shapes of nano-size Cu₂O, and their photocatalytic activities. In the study, we prepared nano-size Cu₂O using surfactant cetyltrimethylammonium bromide（CTAB） as soft template with a novel electrochemical method and characterized the as-prepared samples by XRD, TEM, HRTEM, SEM, BET, XPS ,UV-vis, and IR spectrum. The best experimental conditions was as following: the anodic electrolyte was the aqueous solution of 300g/l NaCl and 0.15g/l CTAB with a piece of copper-plate as the anode;the cathodal electrolyte was the aqueous solution of 1mol/1 NaOH with a piece of stainless steel as the cathode. Under these conditions, when the electrical current was 0.3A, the as-prepared nano-Cu₂O exhibited a six-pod-like, four-horn-shaped morphology and octahedron rystals with many pores in the surface and had large surface area;When the electrical current was 0.1A, the as-prepared nano- Cu₂O exhibited one dimensional shape and well-aligned on the Cu plate. We also discussed the growth mechanism of different shapes of nano-Cu₂O.Photodegradation of Dye Brilliant Red with as-prepared nano-Cu₂O as a catalystwas discussed. For the Dye Brilliant Red solution of lOOmg/1, degradation efficiency can reach 96.64% with 25mg nano-Cu20 under the visible light irradiation for 60min. Photodegradation of formaldehyde was also investigated, and found that formaldehyde can be degraded absolutely.更多还原