多级结构α-MoO3空心微球的构筑及其对有机染料的吸附性能

具有多级结构的半导体金属氧化物, 其特有的立体空间结构使材料具有超高活性, 在吸附领域具有应用潜力。研究采用简单的一步溶剂热法制备了空心球状的MoO₂前驱体, 400 ℃热处理后得到多级结构α-MoO₃空心微球。空心球的直径为600~800 nm, 由宽度约70 nm的纳米棒构筑而成。该球状α-MoO₃纳米材料对亚甲基蓝(MB)染料具有优良的吸附性能。当α-MoO₃吸附剂用量为0.5 g/L、MB染料浓度为20 mg/L、吸附时间为5 min时, 移除率可达到73.40%。吸附60 min时, 吸附达到平衡, 此后移除率为97.53%~99.65%。该吸附动力学过程符合拟二级动力学模型, 吸附等温线符合 Langmuir 模型拟合, 最大吸附量为 1543.2 mg/g。α-MoO₃微球由于多级且中空的纳米结构, 对MB染料具有用量少、吸附速率快和吸附完全等特点。该材料可以用于吸附废水中其他有机染料。

Construction of Hierarchical α-MoO3 Hollow Microspheres and Its High Adsorption Performance towards Organic Dyes

Hierarchical semiconducting metal oxide is highly active due to its special stereostructure, which is potential adsorbent for dye contaminants. Precursors of MoO₂ hollow spheres were successfully synthesized via a simple and one-step solvothermal method. And hierarchical α-MoO₃ hollow microspheres were obtained after subsequent calcination at 400 ℃. Diameters of the α-MoO₃ microspheres were about 600-800 nm which were assembled by nanorods with a width of 70 nm. The as-obtained α-MoO₃ nanomaterials presented excellent adsorption performance for methylene blue (MB). MB removal percentage attained 73.40% in the first 5 min when the concentration of α-MoO₃ absorbent was 0.5 g/L in MB solution at the concentration of 20 mg/L. The equilibrium was established after adsorption for 60 min, and the removal percentages stabilized in the range of 97.53%-99.65%. Their adsorption kinetics was well fitted to a pseudo-second-order model. The adsorption isotherm conformed to Langmuir isotherm model, and the maximum uptake capacity was 1543.2 mg/g. The α-MoO₃ microspheres are cost-effective, fast and complete for MB removal owing to its hierarchical and hollow nanostructures, which also can be employed for adsorption of other organic dyes in waste water.