BiFeO_(3)多铁材料形貌与磁光性能调控研究  

Study and Control on the Morphology and Magneto-Optical Properties of BiFeO_(3) Multiferroic Materials

作　　者：李增鹏 戴剑锋[3] 成晨[3] 冯伟 LI Zengpeng;DAI Jianfeng;CHENG Chen;FENG Wei(State Key Laborotary of Advanced Processing and Recycling of Non-ferrous Metals,School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Key Laborotary of Solar Power System Engineering,Jiuquan Vocational and Technical College,Jiuquan 735000,Gansu,China;School of Science,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]甘肃省太阳能发电系统工程重点实验室,酒泉职业技术学院,甘肃酒泉735000 [3]兰州理工大学理学院,兰州730050

出　　处：《材料导报》2022年第11期47-53,共7页Materials Reports

基　　金：国家自然科学基金(11664023);甘肃省高等学校创新能力提升项目(2020B-375);甘肃省青年科技基金项目(21JR7RF887);陇原青年创新创业团队项目(2020RCXM125)。

摘　　要：铋铁氧体(BiFeO_(3))是在室温下同时具有铁电和铁磁性质的多铁性材料,在微电子、自旋电子学及光降解污染物等领域具有广泛的应用。为了研究不同形貌和尺寸对BiFeO_(3)纳米材料磁光性能的影响,本工作采用静电纺丝法和水热法制备了BiFeO_(3)(BFO)纳米纤维和纳米颗粒,利用X射线衍射仪、X射线光电子能谱仪、扫描电子显微镜、透射电子显微镜、物性测量系统、紫外-可见光谱仪以及多功能控温光化学反应仪对不同形貌、不同尺寸样品的物理和化学性质进行了表征。结果表明:与BiFeO_(3)纳米颗粒相比,BiFeO_(3)纳米纤维具有更小的晶粒尺寸(82~98 nm)和更大的比表面积,能够适度地增强剩余磁化强度(0.042 emu/g),使得BiFeO_(3)纳米纤维的长周期自旋调制的螺旋反铁磁有序结构被破坏,表面未饱和的自旋对纳米纤维总磁矩的贡献变大,且较小的纳米尺度间接提升非补偿表面自旋效应,增强了晶粒间的交换耦合作用。光催化结果显示:具有棒状结构的纳米纤维具有更小的带隙(1.98 eV)、更大的甲基橙(MO)降解率(约63%)以及更高的光催化速率常数(k=0.01161 min^(-1)),能够有效地阻碍光生电子-空穴对的复合,增强了电荷分离效率;同时,具有较大比表面积的纳米纤维使得光催化剂表面的羟基增加,加快了BiFeO_(3)纳米纤维羟基自由基的有效扩散,从而使染色剂分子更易接触催化剂表面区域,更易发生降解,从而具有更好的光催化性能。Bismuth ferrites(BiFeO_(3))are a surprising class of multiferroic materials owning to exhibit both ferroelectric and ferromagnetic properties at room temperature,which is widely used in applications including microelectronics,spintronics and photocatalytic activity.The pure BiFeO_(3)nanofiber and nanoparticle prepared by electrospinning and hydrothermal method respectively were reported for clarifying the influence of various morphologies and size on magneto-optical properties.The X-ray diffractometer,X-ray photoelectron spectroscopy,scanning electron microscopy,transmission electron microscopy,physical property measurement system,UV-Vis spectrophotometer and multi-function temperature control photochemical reaction instrument were used to characterize the physical and chemical properties of samples with different morphologies and sizes.Compared with the BiFeO_(3)nanoparticle,the coexistence of lower crystal size(82—98 nm)and larger specific surface ratio in BFO nanofiber had potential ability to improve the value of remanent magnetization(0.042 emu/g),which lead to destroy the long-period spin-modulated spiral antiferromagnetic order and enhanced the contribution of total magnetic moment.Meanwhile,it has been revealed that the non-compensated surface spin effect and exchange coupling effect were raised due to the lower nano-scale.On the one hand,it was efficiently inhibited the recombination rate of photogenerated e-/h+pairs and enhanced the charge separation efficiency owning to those of BFO nanofiber possessed smaller bandgap(1.98 eV),larger methyl orange(MO)degradation rate(63%)and higher decomposition reaction constant(k=0.01161 min^(-1)).On the other hand,the enhancement of photocatalytic activity of BFO nanofiber with larger spectific surface area can be attributed to the increase of hydroxyl,which could be accelerate to the diffusion of hydroxyl radical,and making the dye molecules more accessibly turn into the catalyst surface area.

关 键 词：形貌 水热法 静电纺丝法 光催化 磁化强度 

分 类 号：O643[理学—物理化学]