Wang Qian, Wang Xiaofei, Tian Bo
School of Materials Science and Chemical Engineering, Xi'an Technological University, No. 2 Middle Xuefu Rd., Weiyang District, Xi'an, Shaanxi 710021, China E-mail:
School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China.
Water Sci Technol. 2018 Jul;77(11-12):2772-2780. doi: 10.2166/wst.2018.265.
Nickel-iron hydrotalcites (NiFe-LDH) with various [Ni]/[Fe] ratios were prepared using co-precipitation method (NiFe-LDH CP) and hydrothermal method (NiFe-LDH HT), respectively. The crystal structure and chemical composition of NiFe-LDHs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry and differential scanning calorimetry (TGA-DSC) and scanning electron microscopy, and NiFe-LDHs were occupied as catalysts to establish heterogeneous Fenton systems for the degradation of methylene blue (MB). The catalytic potential of the catalysts was investigated through cyclic voltammetry analysis. The effects of the dosage of catalyst, initial solution pH and the amount of hydrogen peroxide on the removal of MB were investigated. The results showed that the optimum ratio of [Ni]/[Fe] in the preparation of NiFe-LDHs was 3. NiFe-LDH HT is much smaller and in uniform particle size, with better redox reversible characteristic and catalytic potential. The optimum conditions for the removal of MB catalyzed by NiFe-LDH CP and NiFe-LDH HT were both determined to be 0.15 g/L catalyst, 0.88 mmol/L hydrogen peroxide at pH 2, under which the chemical oxygen demand (COD) removal were 58.96% and 67.87%, respectively. The maximum apparent generation efficiency of ·OH were 46.21% and 49.24%, and NiFe-LDH CP and NiFe-LDH HT were verified to be of high stability.
分别采用共沉淀法（NiFe-LDH CP）和水热法（NiFe-LDH HT）制备了具有不同[Ni]/[Fe]比的镍铁水滑石（NiFe-LDH）。通过X射线衍射、傅里叶变换红外光谱、热重分析和差示扫描量热法（TGA-DSC）以及扫描电子显微镜对NiFe-LDH的晶体结构和化学成分进行了表征，并将NiFe-LDH用作催化剂建立非均相芬顿体系以降解亚甲基蓝（MB）。通过循环伏安分析研究了催化剂的催化潜力。考察了催化剂用量、初始溶液pH值和过氧化氢用量对MB去除率的影响。结果表明，制备NiFe-LDH时[Ni]/[Fe]的最佳比例为3。NiFe-LDH HT粒径更小且均匀，具有更好的氧化还原可逆特性和催化潜力。NiFe-LDH CP和NiFe-LDH HT催化去除MB的最佳条件均确定为催化剂0.15 g/L、过氧化氢0.88 mmol/L、pH值为2，在此条件下化学需氧量（COD）去除率分别为58.96%和67.87%。·OH的最大表观生成效率分别为46.21%和49.24%，且验证了NiFe-LDH CP和NiFe-LDH HT具有高稳定性。
