水热法制备β-CD-金纳米星@TiO_(2)用于可见光催化降解双酚A

Hydrothermal preparation β-CD-Aunanostar@TiO_(2) for visible-light photocatalytic degradation bisphenol A

采用水热法制备了β-CD-金纳米星@TiO_(2)(β-CD-AuNS@TiO_(2))复合光催化材料,用于对双酚A(BPA)的光催化降解.通过紫外-可见光谱(UV-Vis),傅里叶变换红外光谱(FT-IR),扫描电子显微镜(SEM)及透射电子显微镜(TEM)对制备的复合光催化材料的结构进行分析和表征,探索了在可见光下不同种类的催化剂、不同初始浓度的BPA以及pH对BA光降解效果的影响.动力学研究表明β-CD-AuNS@TiO_(2)的反应速率常数约为纯TiO_(2)的3.3倍.捕获实验显示,空穴是β-CD-AuNS@TiO_(2)复合光催化材料的主要活性物种,重复性测试证明催化材料具有良好的稳定性,可以重复利用.

Photocatalytic technology has attracted broad attention due to its advantages of environmental protection,mild reaction conditions,and low cost.Therefore,photocatalytic technology has also been widely applied for various fields.In this paper,supramolecular recognition and plasmonic hot-spot photocatalysis have been combined to improve the selectivity and activity of photocatalysis under wide-range visible-light irradiation through surface modification and fabrication of nanomaterials.β-CD-Au nanostar@TiO_(2)(β-CDAuNS@TiO_(2))composite photocatalytic material was prepared by hydrothermal method for photocatalytic degradation of bisphenol A.We evaluated the photocatalytic activity of theβ-CD-AuNS@TiO_(2)composite photocatalyst and discussed the reaction mechanism of the composite photocatalyst.Finally,the photocatalytic degradation of organic pollutant bisphenol A was achieved under visible-light irradiation.The structure of the composite photocatalytic material was analyzed and characterized through a series of characterization tests such as fourier transform infrared spectroscopy(FT-IR),ultraviolet-visible absorption spectroscopy(UV-Vis),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The results showed that the composite photocatalytic material was successfully prepared.The effects of the surface modification of TiO_(2),the initial concentration of bisphenol A and the pH of reaction system on the photocatalytic degradation efficiency of bisphenol A have been studied.The experimental results showed that the photocatalytic degradation of the preparedβ-CD-AuNS@TiO_(2)for bisphenol A was efficient with a pH of 4.The photocatalytic degradation efficiency of bisphenol A was reached 92.3%.The kinetic experiment indicated that the reaction rate constant ofβ-CD-AuNS@TiO_(2)was 0.0148 min^(-1),which was about 3.3 times that of pure TiO_(2).This was because combine TiO_(2)with plasmonic metals was one of the efficient approaches to extend the light absorption range to visible and NIR region.In addition,AuNS reduced the band gap width of TiO_(2)and slowed down the recombination of photogenerated electron-hole pairs,therefore effectively improved the degradation efficiency of the prepared photocatalyst for bisphenol A.The capture experimented showed that h+was the main active specie of theβ-CD-AuNS@TiO_(2)composite photocatalytic material.The prepared composite photocatalyst had good stability.Replication experiments showed the efficiency of photocatalytic degradation of bisphenol A could still be maintained above 80%after the composite catalyst were reused for 4 times.The outcome of this paper will provide a new way for the treatment of organic pollutants in the future and promote the development of advanced photocatalytic materials.