Preparation Of One Dimensional Nano-size Cuprous Oxide With A Novel Electrochemical Method And Its Photocatalytic Characterization

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.