水热法制备分子筛/硅藻土复合材料及其吸附性能

Preparation of Molecular Sieve and Diatomite Composite by Hydrothermal Method and Its Adsorption Performance

利用酸性水热处理工艺制备具有分子筛结构的硅藻土复合材料,并通过对溶液中亚甲基蓝的饱和吸附率来评价其吸附性能。结果表明:水热处理能够生成具有分子筛结构的新相Variscite 10,当反应时间为2 h时,生成的分子筛/硅藻土复合材料性能达到最佳,其比表面积为96.02 m^2/g,饱和吸附量为98.60 mg/g,比硅藻土原矿增加298.79倍;随着水热反应时间的增加,新相分子筛颗粒变大、结晶度提高,且原有的硅藻壳体管状结构被破坏、比表面积变小,导致对亚甲基蓝的吸附性能降低。水热处理的最佳工艺参数为混合酸质量分数为10%、反应温度180℃、反应时长2 h。

A diatomite composite with a molecular sieve structure was prepared via acid hydrothermal treatment,and its adsorption performance was evaluated by a saturated adsorption rate of methylene blue in solution.The results show that a phase Variscite 10 with a molecular sieve structure can be formed by hydrothermal treatment.The saturated adsorption capacity of the composite with the specific surface area of 96.02 m^2/g is 98.60 mg/g,which is 298.79 times greater than that of the raw diatomite.The size and crystallinity of the molecular sieve particles increase and the diatomite shell with tubular structure destroys as the reaction time increases,leading to the decrease of the adsorption performance of methylene blue.The optimum parameters for hydrothermal treatment are mixed acid of 10%(in mass fraction),reaction temperature of 180℃and reaction time of 2 h.