Atomic-level unveiling secondary recrystallization enabled microand macroscopic polarization enhancement for piezophotocatalytic oxygen activation  

作　　者：Kai Lin Zijian Zhu Weiyi Ge Tianxing Jiang Hongwei Huang 

机构地区：[1]Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources,Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes,National Laboratory of Mineral Materials,School of Material Sciences and Technology,China University of Geosciences(Beijing),Beijing 100083,China [2]School of Chemistry,Beihang University,Beijing 100191,China

出　　处：《Nano Research》2024年第6期5040-5049,共10页纳米研究（英文版）

基　　金：the National Key Research and Development Program of China(No.2022YFB3803600);the National Natural Science Foundation of China(Nos.52272244 and 51972288);the Fundamental Research Funds for the Central Universities(No.2652022202);2021 Graduate Innovation Fund Project of China University of Geosciences,Beijing(No.ZY2021YC006).

摘　　要：Piezoelectric semiconductors bear the bifunctional photocatalysis and piezocatalysis,while the absent or weak internal charge driving force severely restricts its catalytic activity.Developing polarization strategy is desirable,and particularly understanding its mechanism from a microscopic perspective remains scanty.Herein,we report a secondary recrystallization approach to achieving the simultaneous micro-and macroscopic polarization enhancement on Bi2WO6 nanosheets for boosting piezo-photocatalytic oxygen activation,and unravel the mechanism at an atom-level.The secondary recrystallization process not only results in a strengthened distortion of[WO6]octahedra with distortion index enhancement by~20%for a single octahedron,but also enables lateral crystal growth of nanosheets along the ab plane(av.50 to 180 nm),which separately allows the rise in dipole moment of unit cell(e.g.,1.63 D increase along a axis)and the stacking of the distorted[WO6]octahedron to accumulate the unit cell dipole,collectively contributing to the considerably strengthened spontaneous polarization and piezoelectricity.Besides,exposure of large-area{001}front facet enables more efficient capture and conversion of stress into piezo-potential.Therefore,the well-recrystallized Bi2WO6 nanosheets exhibit considerably promoted piezo-photocatalytic reactive oxygen species generation,given the decreased specific surface area.This work presents a feasible methodology to regulate inside-out polarization for guiding carriers transfer behavior,and may advance the solid understanding on the intrinsic mechanism.

关 键 词：secondary recrystallization piezo-photocatalytic oxygen activation octahedron distortion polar units stacking micro-and macroscopic polarization enhancement 

分 类 号：O64[理学—物理化学]