【摘要】 采用直接热分解醋酸铋,在低温下制备了亚稳相β-Bi2O3,采用XRD、TEM、SEM、BET等手段对其进行表征,并研究了水溶液中其光催化降解有机物的性能。结果显示,热分解温度为300℃可得到纯的四方相β-Bi2O3,提高热处理温度(350℃)或延长热处理时间则产物变为α-Bi2O3。TEM和SEM观察发现,所制备的β-Bi2O3为纳米多孔片层结构,孔径大约为30 nm。UV-Vis漫反射谱显示其对可见光有显著的吸收,带隙宽度为2.72 eV。在可见光照射下,该纳米多孔片层β-Bi2O3对甲基橙、罗丹明和4-氯苯酚溶液(10 mg.L-1)的光催化降解均显示了很高的催化活性,当加入0.05 g催化剂时,上述三种有机物能够分别在2 h,2 h,和4 h以内降解。β-Bi2O3的高光催化活性可归因于其高比表面积以及纳米级结构。更多还原

【Abstract】 A metastable porous sheet-like β-Bi2O3 was fabricated by the thermal decomposition of bismuth acetate at a relative low temperature.The catalysts were characterized by XRD,TEM,SEM,BET and DRS,and the photo-catalytic activity was evaluated by degrading of organic pollutants.The results showed that pure tetragonal β-Bi2O3 samples could be obtained at 300 ℃,while increasing the thermal treatment temperature to 350 ℃ or to longer time,the product was α-Bi2O3.TEM and SEM results revealed that the samples were sheet-like with pores at the size of 30 nm.UV-Vis spectra results showed that the samples had obvious photoadsorption in visible light region,and the band gap(Eg) was 2.72 eV.The β-Bi2O3 samples exhibited very excellent photocatalytic activity for the degradation of methyl orange,rhodamine B and 4-chloropheno(10 mg·L-1) under visible light.While 0.05 g catalysts were used,these three kinds of organic pollutants could be degraded in less than 2 h,2 h,and 4 h,respectively.The excellent photo-catalytic performance was due largely to the high BET surface area,and nano-structure.更多还原