Diatomite in situ loaded by MOF (ZIF-8) and its application in removing methylene orange from aqueous solutions

Diatomite is extensively used as a natural environmental material because of its biogenic origin and stable structure. The zeolitic imidazolate framework (ZIF-8) is a prototypical metal-organic frame (MOF) that is well known for its high surface areas and chemical stability. Herein, a facile method for the generation of diatomite in situ loaded by ZIF-8 (D/Z) was reported. The results of powder x-ray diffraction (PXRD) analysis confirmed the successful loading of ZIF-8 on the diatomite. The ZIF-8 were distributed uniformly on the surface of the diatomite from the scanning electron microscope (SEM) images. The specific surface of the D/Z increased due to the loading of the ZIF-8. Methylene orange (MO-) in an aqueous form was efficiently separated and removed through a simple mixture and filtration process where the D/Z was employed as an absorbent, and the removal rate of the MO- increased in the case of the sample with more ZIF-8 loaded on the diatomite. In addition, the D/Z was reused after several regenerations by washing out the adsorbed dye.