文献类型：期刊文献

中文题名：电晕极化对钛酸钡粉体压电光催化性能的影响

英文题名：Effect of Corona Poling on Piezo-Photocatalytic Performance of Barium Titanate Powders

作者：杨伟雪[1];卢袁真子[2];王宝苑[1];王炳博[1];王梓鉴[2];侯莹[1]

机构：[1]华东理工大学物理学院,上海200237;[2]中国科学技术大学物理学院,合肥230026

年份：2024

卷号：52

期号：9

起止页码：2889

中文期刊名：硅酸盐学报

外文期刊名：Journal of The Chinese Ceramic Society

收录：CSTPCD;;EI(收录号：20244017147617);Scopus;北大核心:【北大核心2023】；CSCD:【CSCD2023_2024】；

基金：国家自然科学基金(52272109)。

语种：中文

中文关键词：钛酸钡;压电光催化;电晕极化;罗丹明B

外文关键词：barium titanate;piezo-photocatalysis;corona poling;Rhodamine B

摘要：采用溶胶-胶法制备钛酸钡(BaTiO_(3),BT)粉体,通过改变保温时间(2、5、12 h)获得了不粒径尺寸的BT纳米颗粒。将BT纳米粉体在6.56 kV电压下分别进行1 h电晕极化,探究极化前后晶格的畸变程度以及粉体的压电光催化性能。结果表明:随保温时间延长,颗粒粒径尺寸增大,极化后晶体的晶格畸变程度增强,四方度提高。同时,极化使得3组粉体对染料的降解速率大幅提升,动力学速率常数分别为极化前的4.94、2.21、1.62倍,与晶格畸变程度呈现相同规律。其中,保温2 h的粉体电晕极化后对有机染料罗丹明B(RhB)的降解率在180 min内达到96.81%,具有最优的压电光催化性能,这为电晕极化在粉体催化领域的应用提供了实验参考。
Introduction Photocatalysis is an effective technology to solve environmental pollution.Ferroelectric ceramics,as a new type of catalyst,have been received widespread attention mainly attributed to the ability to reduce the recombination rate of photo-induced carriers and to improve catalytic performance by building a built-in electric field.In order to avoid the decrease of remanent polarization in ceramic bulks during the traditional poling technology and simplify the poling process,corona poling technology has been used for the poling of powders.Several researches indicated that corona poling could significantly improve the catalytic performance,while the relationship among the particle size,phase structure,and piezo-photocatalytic performance was still not so clear.Therefore,BaTiO_(3)(BT)nanoparticles with different particle sizes were prepared via sol-gel method and then polarized these powders for 1 h under a voltage of 6.56 kV.The phase structures and the lattice distortion before and after poling were carefully explored.In addition,the effect of corona poling on the piezo-photocatalytic performance of BT powders was investigated,Rhodamine B(RhB)was utilized as the target pollutant.Methods Barium acetate(C_(4)H_(6)O_(4)Ba)and tetrabutyl titanate(C_(16)H_(36)O_(4)Ti)were used as raw materials,both were dissolved in acetic acid and ethanol,respectively.Subsequently,these two solutions were mixed and then stirred for 3 h,after that,the solution was left to stand for 16 h,and then dried in an oven at 70℃for 24 h.The mixtures were calcined at 800℃for 2,5 h and 12 h,respectively,in order to obtain BT powders with different particle sizes(the corresponding BT powders were respectively referred to as 2,5 h and 12 h).A SmartLab type X-ray diffractometer(XRD)was used to analyze the crystal structure of the obtained powders.The obtained powders were measured using an Invia Reflex model laser micro Raman spectrometer(Raman).In addition,the Helios G4 UC type scanning electron microscopy(SEM)was used to observe the surface morphology of the obtained powders.A Mapada UV-6300 UV-Vis spectrophotometer(UV-Vis)was used to characterize the transmittance of the obtained powders,thereby evaluating the degradation rate of powders.A home-made corona poling set-up at 6.56 kV for 1 h was used to polarize the BT powders.The unpoled/poled BT powders were mixed in RhB and stirred for 30 min to complete the dark adsorption.A Xe lamp(300 W)was used to simulate the sunlight irradiation,and an ultrasonic machine(30 kHz,100 W)was used to assist in completing the piezo-photocatalytic test.Results and discussion Particle sizes of the 2,5 h and 12 h BT powders were 55,110 nm,and 130 nm,respectively.XRD patterns showed that the cubic and tetragonal phases coexisted for all kinds of samples,and Raman spectroscopy confirmed the presence of tetragonal phases.The c/a values of tetragonal phase(c_(T)/a_(T))in these BT powders,evaluated by Rietveld refinement analysis,were 1.00785(2 h-unpoled),1.00800(5 h-unpoled),and 1.00910(12 h-unpoled),respectively,these were closely related to the particle size.The larger size corresponded to the higher c_(T)/a_(T),illustrating that the ratio of the tetragonal phase would be increased in 12 h BT nanoparticles.After corona poling process,the lattice distortion further strengthened and the c_(T)/a_(T)values were 1.00889(2 h-poled),1.00844(5 h-poled),and 1.00932(12 h-poled),respectively.The difference of c_(T)/a_(T)between unpoled and poled BT powders(Δ(c_(T)/a_(T)))was significantly decreased with the increase of particle size,demonstrating the higher poling effectiveness in nanoparticles with smaller size.Moreover,effect of poling on the piezo-photocatalytic performance of samples was evaluated via observing the degradation of RhB.It was found that the piezocatalysis existed a"bottleneck period",being related to the pressure pulse generated by cavitation bubbles and the free charges generated by particles through surface friction.The reaction rate constants k for unpoled BT powders were 0.00328 min^(-1)(2 h-unpoled),0.00439 min^(-1)(5 h-unpoled),and 0.00382 min^(-1)(12 h-unpoled),respectively.After poling,the k values were 0.01620 min^(-1)(2 h-poled),0.00969 min^(-1)(5 h-poled),and 0.00620 min^(-1)(12 h-poled),4.94,2.21 and 1.62 times higher than before poling,respectively,mainly attributed to the enhancement of the built-in electric field caused by corona poling,which could increase the driving force for the separation of photo-induced carriers and prolong the lifetime of carriers.Among them,the 2 h-poled powder exhibited the highest rate constant and a degradation efficiency of 96.81%,as that particle size of 2 h-poled samples was smaller than that of 5 h powders and 12 h powders,resulted in a high degree of lattice distortion and enhanced the tetragonality.Moreover,the small particle size of samples was considered to be favorable for the sufficient contact with RhB.Therefore,highest reaction rate constant and degradation efficiency were achieved for the 2 h-poled sample.Conclusions BT powders with different particle sizes were prepared and poled by corona poling technology.Effect of the poling process on the degree of lattice distortion,phase structure,and piezo-photocatalytic performance for degrading RhB of BT powders was systematically investigated.Results indicated that the corona poling could deepen the crystal lattice distortion and increase the tetragonality of BT nanoparticles.In addition,poling process could enhance the built-in electric field,reduce the recombination rate of photo-induced carriers,and significantly improve catalytic performance.The rate constants k of the poled powders were 4.94 times(2 h-poled),2.21 times(5 h-poled),and 1.62 times(12 h-poled)higher than those of unpoled BT powders.Among all samples without and with poling process,the 2 h-poled BT powder achieved the highest degradation efficiency of 96.81%within 180 min,indicated the optimal piezo-photocatalytic performance.This work could provide a simple and rational method to design ferroelectric materials for achieving the high catalytic performance.