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按2~5部分因子试验设计安排实验,以光催化降解甲基橙(MO)溶液脱色率DC(%)为目标值,考察掺锰量V_(MnNO3)、熟化温度T_1、熟化时间t_1、煅烧温度T_2和煅烧时间t_2对制备的Mn掺杂纳米ZnO光催化性能的影响,经分析确定影响产品光催化性能的主要因素为V_(MnNO3)、T_1和T_2。以此3因素按3~2全因子试验设计进行实验并分析试验结果,获得Mn掺杂纳米ZnO光催化剂的优化制备条件为V_(MnNO3)=0.5mL、T_1=70℃、t_1=15min、T_2=600℃和t_2=2.5h。0.05g优化制备产品在紫外光照射下光催化降解100mL10mg/L的MO溶液30min的DC实验平均值为95.58,与Minitab软件对产品的优化预测值95.75的相对误差仅为-0.18%;在可见光下降解MO溶液120min的DC实验平均值为65.11。XRD和SEM对优化产品的表征表明,其主要由粒径分布在(20～30)nm的不规则的颗粒状纳米ZnO组成。由紫外-可见分光光度计测定并计算得出优化产品的带隙能E_g约为3.25eV,较同等条件下制得的纳米ZnO带隙能E_g(3.36eV)低0.11eV。
According to the design experiment of 2 ~ 5 part factor experiments, the decolorization rate DC (%) of photocatalytic degradation of methyl orange (MO) solution was taken as the target value. The effects of MnO3 dosage, aging temperature T_1, aging time t_1, calcination The effects of temperature T_2 and calcination time t_2 on the photocatalytic activity of Mn doped ZnO were investigated. The main factors affecting the photocatalytic activity were V MnNO 3, T 1 and T 2. Based on these three factors, experiments were carried out according to the 3 ~ 2 factorial design and the experimental results were obtained. The optimal preparation conditions for the Mn doped ZnO nanoparticles were V_ (MnNO3) = 0.5mL, T_1 = 70 ℃, t_1 = 15min, = 600 ℃ and t_2 = 2.5h. 0.05g optimal preparation of products under UV light photocatalytic degradation of 100mL10mg / L of MO solution for 30min DC experiment average of 95.58, and Minitab software optimized prediction value of 95.75 relative error of only -0.18%; in the visible light down The DC experiment of solution of MO solution for 120min averaged 65.11. Characterization of the optimized products by XRD and SEM showed that the particles mainly consisted of irregularly granular nano-ZnO with particle size distribution (20-30 nm). The bandgap energy E_g of the optimized product was about 3.25eV as determined by UV-visible spectrophotometer and calculated to be 0.11eV lower than the bandgap energy E_g (3.36eV) of nano-ZnO prepared under the same conditions.