Catalytic degradation of gaseous benzene by using TiO2/goethite immobilized on palygorskite: Preparation, characterization and mechanism

• The TiO2/goethite/palygorskite photocatalytic composite was prepared and analyzed.
• TiO2/goethite/palygorskite composite exhibited good photocatalytic synergistic effect.
• Electron–holes and oxygen synergy effect were responsible for benzene degradation.

The nano-TiO2/goethite/palygorskite catalysts were prepared by sol–gel method. The morphology and structure of the catalysts were analyzed by X-ray diffraction (XRD), UV–Vis reflection spectrometer, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and N2 adsorption-desorption measurement. The results indicated that the self-made catalysts had excellent catalytic performance on gaseous benzene degradation. In the case of benzene concentration at 30 mg/m3, the degradation efficiency, over TiO2/goethite/palygorskite composite with mass ratio of 10:5:5, reached 70.4% after 180 min 254 nm UV irradiation. The reaction mechanism and kinetics study showed that palygorskite/goethite/TiO2 composites photocatalytic degradation benzene was mainly caused by oxidizing property of electron–holes and oxygen synergy effect.

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