La掺杂钛酸铋纳米片的合成及其压电-光催化性能探索性实验设计  

Exploratory experimental design for the synthesis of La-doped bismuth titanate nanosheets and their piezoelectric photocatalytic properties

作　　者：陈志武[1] 王歆[1] CHEN Zhiwu;WANG Xin(School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《实验技术与管理》2025年第3期54-59,共6页Experimental Technology and Management

基　　金：国家自然科学基金项目(22272057);华南理工大学探索性实验项目(x2clC9238110)。

摘　　要：该文将稀土掺杂钛酸铋纳米片的合成及其压电-光催化性能研究设计成探索性实验项目。该实验采用一步熔盐法和固相法分别合成了Bi_(4-x)La_(x)Ti_(3)O_(12)(x=0,0.75)薄片和不规则的Bi_(4)Ti_(3)O_(12)颗粒,研究了La掺杂对样品形貌及压电-光催化性能的影响。其中,Bi_(3.25)La_(0.75)Ti_(3)O_(12)纳米片的压电光催化效率最高,仅在60 min内就实现了甲基橙的完全降解,其表观速率常数分别是Bi_(4)Ti_(3)O_(12)不规则颗粒和Bi_(4)Ti_(3)O_(12)薄片的约2.26倍和1.60倍。通过深入分析能带结构、光电流曲线及压电响应,提出了Bi_(3.25)La_(0.75)Ti_(3)O_(12)压电增强光催化活性的机理。该探索性实验项目在激发学生学习兴趣、深化理论知识和培养科研创新能力方面具有很好的促进作用。[Objective]Conventional semiconductor photocatalysts suffer from a high photogenerated electron and hole combination rate,which significantly reduces photocatalytic efficiency.Recently,much attention has been paid to piezo-photocatalysis,a technique in which a piezoelectric field induces the separation of photogenerated carriers,thereby significantly enhancing photocatalytic efficiency.Bi_(4)Ti_(3)O_(12) exhibits commendable visible-light photocatalytic performance due to its relatively small band gap.More importantly,Bi_(4)Ti_(3)O_(12) is a piezoelectric material,and external stress can induce the piezoelectric polarization of Bi_(4)Ti_(3)O_(12),which in turn can generate an internal piezoelectric field,making Bi_(4)Ti_(3)O_(12) one of the best candidates for use in piezo-photocatalysis.The piezophotocatalytic properties of Bi_(4)Ti_(3)O_(12)-based materials can be further enhanced by synthesizing them as nanosheets and doping them with rare-earth ions.In this work,synthesizing La-doped Bi_(4)Ti_(3)O_(12) nanosheets and studying their piezophotocatalytic properties were designed as exploratory experimental projects.[Methods]Bi_(4-x)La_(x)Ti_(3)O_(12)(x=0 and 0.75)sheets and irregular Bi_(4)Ti_(3)O_(12) particles were synthesized using a one-step molten-salt and a solid-phase method,respectively,and the effects of the synthesis method and La doping on the morphology and piezophotocatalytic properties of samples were investigated.The prepared catalysts were characterized using X-ray diffraction,scanning electron microscopy,a UV–Vis spectrophotometer,and an electrochemical analyzer.A PFM module in the AFM test system was utilized to monitor the piezoelectric responses of samples.Light irradiation,ultrasonic excitation,and light and ultrasonic co-excitation were used to study the catalytic activity of samples for degrading methyl orange(MO).[Results]XRD results indicate that Bi_(4)Ti_(3)O_(12) with high purity is successfully synthesized by solid-phase and molten-salt methods.The Bi_(4)Ti_(3)O_(12) sample synthesi

关 键 词：探索性实验 La掺杂钛酸铋 压电-光催化 光催化 纳米片 

分 类 号：G642.0[文化科学—高等教育学] X522[文化科学—教育学]