实验技术与管理2025，Vol.42Issue(3)：54-59,6.DOI:10.16791/j.cnki.sjg.2025.03.007
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
摘要
Abstract
[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.Bi4Ti3O12 exhibits commendable visible-light photocatalytic performance due to its relatively small band gap.More importantly,Bi4Ti3O12 is a piezoelectric material,and external stress can induce the piezoelectric polarization of Bi4Ti3O12,which in turn can generate an internal piezoelectric field,making Bi4Ti3O12 one of the best candidates for use in piezo-photocatalysis.The piezophotocatalytic properties of Bi4Ti3O12-based materials can be further enhanced by synthesizing them as nanosheets and doping them with rare-earth ions.In this work,synthesizing La-doped Bi4Ti3O12 nanosheets and studying their piezophotocatalytic properties were designed as exploratory experimental projects.[Methods]Bi4-xLaxTi3O12(x=0 and 0.75)sheets and irregular Bi4Ti3O12 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 Bi4Ti3O12 with high purity is successfully synthesized by solid-phase and molten-salt methods.The Bi4Ti3O12 sample synthesized using the solid-phase method consists mainly of irregular particles,while Bi4-xLaxTi3O12(x=0 and 0.75)synthesized by the molten-salt method is composed of well-defined sheets.La doping leads to reductions in the nanosheet size and thickness.Among all samples,Bi3.25La0.75Ti3O12 nanosheets exhibit the highest piezophotocatalytic efficiency,achieving complete MO degradation in just 60 min.The apparent rate constant of Bi3.25La0.75Ti3O12 is approximately 2.26 and 1.60 times greater than those of Bi4Ti3O12 irregular particles and Bi4Ti3O12 sheets,respectively.Bi3.25La0.75Ti3O12 has favorable conduction band locations,a higher specific surface area,reduced nanosheet thickness,and a stronger piezoelectric effect than pure Bi4Ti3O12.[Conclusions]Bi4-xLaxTi3O12(x=0 and 0.75)nanosheets,efficiently fabricated via a one-step molten-salt method,exhibit superior piezophotocatalytic activity than Bi4Ti3O12 irregular particles prepared by the solid-state-phase method.Among all samples,Bi3.25La0.75Ti3O12 demonstrates the highest piezophotocatalytic efficiency in MO degradation under light and ultrasonic co-excitation.This study demonstrates that the utilization of the molten-salt method and an appropriate amount of La doping increases the specific surface area,optimizes the energy band structure,as well as promotes the synergy between the piezoelectric and photocatalytic effects,leading to the excellent piezophotocatalytic activity of Bi3.25La0.75Ti3O12.This exploratory experimental project plays an important role in stimulating students'learning interests,deepening their theoretical knowledge,and cultivating their scientific research and innovation abilities.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Key words
exploratory experiment/La-doped bismuth titanate/piezo-photocatalysis/photocatalysis/nanosheets分类
社会科学引用本文复制引用
陈志武,王歆..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[J].实验技术与管理,2025,42(3):54-59,6.基金项目
国家自然科学基金项目(22272057) （22272057）
华南理工大学探索性实验项目(x2clC9238110) （x2clC9238110）
