Photocatalytic Degradation of Acetone over Sulfated MoOx/MgF2 Composite: Effect of Molybdenum Concentration and Calcination Temperature

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• 作者：Yiming He ; Leihong Zhao ; Yongjiao Wang ; Tingting Li ; Tinghua Wu ; Xintao Wu ; Ying Wu
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2011
• 出版时间：June 15, 2011
• 年：2011
• 卷：50
• 期：12
• 页码：7109-7119
• 全文大小：1242K
• 年卷期：v.50,no.12(June 15, 2011)
• ISSN：1520-5045

文摘

This paper presents a novel visible-light-driven catalyst, a SO₄^{2鈥?/sup>/MoO_x/MgF₂ composite, which was synthesized by a simple solution method. Multiple techniques, including Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS) were applied to investigate the physical and photophysical properties of the catalysts. The photocatalytic activities were evaluated in the degradation of acetone in gas phase. In the photodegradation of acetone, the highest conversion was obtained over a catalyst containing 5 mol鈥? molybdenum. The XRD and Raman characterizations indicate that the molybdenum oxide was highly dispersed in the MgF₂ matrix. These MoO_x species might be the active sites of the catalysts, which is the reason for the visible-light response of the composite catalyst. The MgF₂ matrix acts to isolate the MoO_x species and retard the electron鈥揾ole pair recombination. When the molybdenum concentration is >5 mol鈥?, crystalline MoO₃ phase was observed. The large MoO₃ particle would decrease the separation efficiency. Thus, the photocatalytic activity was reduced. Besides the molybdenum concentration, the calcination temperature also shows a great effect on the activity. A sulfated 5 mol鈥? MoO_x/MgF₂ catalyst that was calcined at 350 掳C showed the highest photocatalytic activity. Based on the results of the characaterization, the origin of the high activity was discussed. The light absorption ability and the MoO_x size effect are considered as the key factors.}