Sonocatalytic activity of LuFeO_3 crystallites synthesized via a hydrothermal route  

水热法制备的LuFeO_3晶粒的超声催化活性（英文）

作　　者：周明[1] 杨华[1] 县涛[1] 杨阳[1] 张云川[1] 

机构地区：[1]兰州理工大学理学院,甘肃兰州730050

出　　处：《Chinese Journal of Catalysis》2015年第11期1987-1994,共8页催化学报（英文）

基　　金：supported by the National Natural Science Foundation of China(51262018);the Fundamental Research Funds for Universities of Gansu Province(056003);the Hongliu Outstanding Talents Foundation of Lanzhou University of Technology(J201205)~~

摘　　要：LuFeO3 crystallites of different sizes and morphologies were synthesized via a hydrothermal route. The sonocatalytic properties of the as-synthesized samples were investigated by degrading various organic dyes, including acid orange 7 （AOT）, rhodamine B （RhB）, methyl orange （MO）, and methylene blue （MB）, under ultrasonic irradiation, revealing that they exhibit excellent sonocatalytic activity toward the degradation of these dyes. Particularly, the synthesized bar-like particles with lengths of-3 μm and widths of-1μm have the highest sonocatalytic activity, and the degradation percentage of AO7 reaches 89% after 30 min of sonocatalysis. The effects of inorganic anions such as CI-, NO3-, SO42-, PO43-, and HCO3- on the sonocatalysis efficiency were investigated. Hydroxyl radicals （·OH） detected by fiuorimetry using terephthalic acid as a probe molecule were found to be produced over the ultrasonic-irradiated LuFeO3 particles. The addition of ethanol, which acts as a· OH scavenger, leads to quenching of ＂OH radicals and a simultaneous decrease in the dye degrada- tion. This suggests that ＂OH is the dominant active species responsible for the dye degradation.超声波在水中传播时会产生大量空化气泡,空化气泡经历成核、生长和瞬间崩塌等过程,并在崩塌瞬间产生局部高温和高压,过程中会发出瞬间闪光,即声致发光.局部高温高压及声致发光可将半导体价带上的电子激发至导带,形成电子/空穴对,电子和空穴迁移至半导体颗粒表面,参与一系列氧化还原反应致使有机污染物发生分解.由于超声波在各种液体中都具有很强的穿透能力,因此与半导体光催化技术相比,半导体超声催化技术在降解高浓度和不透明染料废水时具有明显优势.LuFeO3是稀土正铁氧体中的一员,具有独特磁结构、巨介电常数及多铁性,近年来引起了人们极大的研究兴趣.同时,LuFeO3也是一种窄带隙半导体材料,使其可以作为一种潜在的超声催化剂,但相关报道很少.半导体材料的晶粒尺寸及形貌对其超声催化活性的影响非常大,因此制备出不同晶粒尺寸及形貌的LuFeO3颗粒并研究其超声催化性能具有重要意义.目前LuFeO3的主要制备方法为传统的固相反应法,该法需要反复研磨和高温煅烧使原料彻底反应,而且制备出的颗粒尺寸较大,相互粘连严重,形貌难以控制.在众多纳米材料制备方法中,水热法在调控晶粒尺寸及形貌上具有巨大优势.本课题组曾采用水热法成功制备了单相的LuFeO3颗粒,通过改变Na OH浓度,可以对产物的晶粒尺寸及形貌进行调控.基于此,本文以酸性橙(AO7)、罗丹明B(RhB)、甲基橙(MO)和亚甲基蓝(MB)为目标降解物,考察了水热法所制备的LuFeO3颗粒在超声辐照下的超声催化性能,并系统研究了晶粒尺寸及形貌、无机离子和乙醇对LuFeO3颗粒超声催化活性的影响及LuFeO3颗粒重复利用性能.以对苯二甲酸(TPA)为分子荧光探针,采用光致发光(PL)技术检测在超声辐照下LuFeO3反应液中产生羟基自由基(·OH)的情况,探讨了LuFeO3颗粒的超声催化机理.超声催化反应结�

关 键 词：Lutetium orthoferrite Hydrothermal synthesis Sonocatalytic activity Hydroxyl radical Inorganic anion Degradation of organic dyes 

分 类 号：O614.347[理学—无机化学] O643.36[理学—化学]