摘要
通过对铁电光催化剂Bi2MoO6和聚甲基丙烯酸甲酯(PMMA)构建的有机-无机复合膜材料施加电场极化,来探究铁电极化对Bi2MoO6光催化剂活性提升的影响。未极化的Bi2MoO6在光照40 min时降解罗丹明B(RhB)的效率为57.6%,在光照150min时对双酚A(BPA)的降解效率为33.4%。在15 V电压下极化1.5 h的Bi2MoO6材料在相同条件下降解罗丹明B和双酚A的效率分别达到98.1%和79.2%,光催化活性得到了较大的提升。光催化活性提升的原因归因于内部电场的增强。未极化的Bi2MoO6的内电场的铁电畴是无序、分布不均匀的,光生载流子非常容易发生体内复合。当外加电场极化Bi2MoO6时,Bi2MoO6的铁电畴趋于有序,极化方向趋于同一方向,表面一侧(C^+区)产生正电荷,在另一侧(C^-区)产生负电荷,从C^-区指向C^+区的极化电场推动光生电子和空穴分别迁移到C^+和C^-区域。这一过程促使光生电荷载流子快速从体内迁移至表面,提高和延长了光生载流子的分离效率和寿命,导致光催化活性的提升。
The effect of ferroelectric polarization on the activity enhancement of Bi2MoO6 photocatalyst was explored by applying ferroelectric field polarization to organic-inorganic composite film materials constructed by ferroelectric photocatalyst Bi2MoO6 and polymethyl methacrylate(PMMA).The efficiency of unpolarized Bi2MoO6 degradation of rhodamine B(RhB)was 57.6%under 40 min light irradiation,and the degradation efficiency of bisphenol A(BPA)was 33.4%under 150 min light irradiation.The photocatalytic activity of Bi2MoO6 material polarized for 1.5 h at 15 V voltages was greatly enhanced,and the degradation efficiency of RhB and BPA under the same conditions reached 98.1%and 79.2%,respectively.The reason for the enhancement of photocatalytic activity is attributed to the enhancement of the internal electric field.The ferroelectric domains of the internal electric field of unpolarized Bi2MoO6 were disordered and unevenly distributed,and photogenerated carriers were very prone to recombination.When the applied electric field polarized Bi2MoO6,the ferroelectric domains of Bi2MoO6 tended to be ordered,and the polarization direction tended to be the same.Positive charges were generated on one side of the surface(C^+re-gion)and negative charges were generated on the other side(C^-region).The polarized electric field from C^-region to C^+region drives the photogenerated electrons and holes to migrate to C^+and C^-regions,respectively.This process promotes the rapid migration of photogenerated charge carriers from the interior to the surface,improves and pro-longs the separation efficiency and lifetime of photogenerated carriers,leading to the enhancement of photocatalytic activity.
作者
邹晨涛
张志
廖文静
杨水金
ZOU Chen-Tao;ZHANG Zhi;LIAO Wen-Jing;YANG Shui-Jin(College of Chemistry and Chemical Engineering,Hubei Key Laboratory of Pollutant Analysis&Reuse Technology,Hubei Normal University,Huangshi,Hubei 435002,China;Institute for Advanced Materials of Hubei Normal University,Huangshi,Hubei 435002,China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2020年第9期1717-1727,共11页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.21171053)
湖北省自然科学基金重点项目(No.2014CFA131)资助。
关键词
光催化
半导体
Bi2MoO6
极化
可见光
双酚A
photocatalysis
semiconductors
Bi2MoO6
polarization
visible light
bisphenol A
