The Research On The Production And Photocatalysis Property Of One-dimensional Cuprous Oxide

Photocatalysis is emerging as a promising technology for wastewater treatment. The advantages of this technique include reaction thoroughly, high degradation efficiency, cheap raw materials, chemical stability and the potential to utilize sunlight as light source. This technique has great superiority over the traditional waste water treatment. At present, the successful use of photocatalyst is TiO2, which can be used to degrade organic contamination with dramatic effects. However, TiO2 has some shortcoming. For example, this kind of matter needs the ultraviolet ray to inspire, thus using the visible light as the light energy to processing sewage always is a goal which the experts and scholars pursues. And cuprous oxide's band gap is about 2.2eV, which is a scarce semiconductor materials excited by 390nm-780 nm wavelength of the visible light. In addition to, Cu2O has the properity of nontoxic, wide source and high theory efficiency. In 1998, Ikeda et al used Cu2O to decompose H2O to H2 and O2. It means that Cu2O has good light catalytic as a promising catalyst under visible light.Quasi one-dimensional nano-materials's special optical, electrical and magnetic properties interested many scientists's attention. There are many methods to prepare quasi one-dimensional Cu2O nano-materials, including low-temperature solid-phase method, templates, electricity deposition, hydrothermal/solvent calorimetry, liquid phase reduction method, etc. Using sulfites reduction method to prepare Cu2O is the most traditional liquid phase reduction method, but using this method to prepare one-dimensional Cu2O researches have not been reported so far.In our study, we main tried to prepare one-dimensional (1-D) cuprous oxide (Cu2O) with sulfites reduction method and study their photocatalytic activities and thermal stability. In the experiment, we prepared successfully 1-D Cu2O with sulfites reduction method whose surfactant is cationic cetyltrimethylammonium bromide (CTAB). The as-prepared samples are characterized by XRD, SEM, DTA-TG. The best experimental conditions were as following:Under the precondition of using copper sulfate solution (CuSO4·5H2O) and sodium acetate/ethylic acid (NaAc/HAc) solution mixed, sodium sulfite (Na2SO3) solution and CTAB solution mixed, club-shaped cuprous oxides were obtained, whose length is 5～10μm, diameter is 0.2～0.5μm and length-diameter ratio is 10～30, when the concentrations of the copper source was 0.075mol/L, CTAB was four times critical micelle concentration (4 CMC), reaction temperature was 90℃, reaction time was 120min and mixing time was 10min. We also discussed the growth mechanism of one-dimensional cuprous oxide.We discussed the photodegradation of methyl orange solution with as-prepared 1-D Cu2O as light catalyst in visible light. For the methyl orange solution of 40mg/L in 100mL solution, degradation efficiency can achieve 94.2% with 120mg one-dimensional Cu2O under the visible light irradiation for 90min. Finally, the 1-D Cu2O produced with sulfites reduction method was analyzed by Kissinger method and FWO method. The result was that activation energy of 1-D Cu2O was 174.52KJ·mol-1, the pre-exponential factor was 7.16×1012, and the reaction order was 0.99. The 1-D Cu2O has good thermal stability at room temperature, stationary air through repeated experiments demonstration.