Preparation of ZnO/sepiolite composite and its photocatalytic performance for the water decontamination

The photocatalysis technology has become an important means to control environmental pollutions especially water pollution. A new ZnO/sepiolite composite was prepared using the sol-gel method by taking the nontoxicity, high catalytic activity, high stability, and strong antioxidant capacity of ZnO and the large pore volume and specific surface area, strong adsorption capacity, light weight, and strong chemical stability of sepiolite to prepare improved photocatalytic materials. The microrepresentation and contrast analysis of structures and morphologies of sepiolite and ZnO/sepiolite composite were performed using scanning electron microscopy, Fourier transform infrared spectrometry, and TD-3500 X-ray diffraction. The degradation capacities of sepiolite, ZnO, and ZnO/sepiolite composite into formaldehyde, malachite green, methylbenzene, and landfill leachate were tested under UV light. Results show that ZnO can be loaded onto sepiolite successfully and that ZnO ions form a tight coupling interface after entering the sepiolite layer. The formed crystals are small. The pore ratio increases synonyms, and the adsorption performance improves accordingly. Moreover, sepiolite can inhibit the agglomeration of ZnO particles effectively. The ZnO/sepiolite composite is significantly superior to sepiolite and ZnO in the treatment of above pollutants. The composite has degraded 88.57% of formaldehyde, 91.3% of malachite green, 66.53% of methylbenzene, and 76.38% of landfill leachate. Compared with other types of composite photocatalyst, the ZnO/sepiolite composite has better photocatalytic performances, and its degradation of organic pollutants conforms to the first-order kinetics. Finally, the ZnO/sepiolite composite has high reusability due to easy recovery and good chemical and photocatalytic stabilities. The ZnO/sepiolite composite provides a new selection to control environmental pollutions and possesses promising application prospects.