Over the last several years,piezo-photocatalytic effect was intensively investigated for a facile,effective and promising protocol to sewage treatment and environmental remediation.The research on the integration of p...Over the last several years,piezo-photocatalytic effect was intensively investigated for a facile,effective and promising protocol to sewage treatment and environmental remediation.The research on the integration of piezocatalytic and photocatalytic process on lead-free ferroelectric materials is highly demanded to further push this field forward.In this work,BaTiO_(3) nanowires(BT NWs)were fabricated by a two-step hydrothermal method.The degradation of organic dye(methyl orange,MO)aqueous solution(5 mg L^(-1))by integrating photocatalysis with the piezoelectric-like effect under UV light radiation and ultrasonic vibration was investigated.The decomposition ratio reaches up to ~98.17%(at 80 min),which is around 1.28 and 2.24 times of the sole piezocatalysis and photocatalysis process,respectively.The intermediate product of hydroxyl radical(·OH)and superoxide radical(·O_(2)^(-))was detected and quantified by radical trapping experiments,to illustrating their key role in degrading MO molecules.In addition,we carried out sequential cycles to evaluate the cycling stability and usage durability of catalysts and a reduction of ~15% in the efficiency was observed after four cycles.This work provides a promising paradigm for the further development of piezo-photocatalytic materials and target applications in environmental field.展开更多
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...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.展开更多
基金supported by the Start-up Funding of Wuhan University of Technology(Grant No.40120490)National Natural Science Foundation of China(Grant No.51672198)+1 种基金Primary Research Plan of Shandong Province(Grant No.2016CYJS07A03-2)Innovation and Development Project of Zibo City(Grant No.2017CX01A022).
文摘Over the last several years,piezo-photocatalytic effect was intensively investigated for a facile,effective and promising protocol to sewage treatment and environmental remediation.The research on the integration of piezocatalytic and photocatalytic process on lead-free ferroelectric materials is highly demanded to further push this field forward.In this work,BaTiO_(3) nanowires(BT NWs)were fabricated by a two-step hydrothermal method.The degradation of organic dye(methyl orange,MO)aqueous solution(5 mg L^(-1))by integrating photocatalysis with the piezoelectric-like effect under UV light radiation and ultrasonic vibration was investigated.The decomposition ratio reaches up to ~98.17%(at 80 min),which is around 1.28 and 2.24 times of the sole piezocatalysis and photocatalysis process,respectively.The intermediate product of hydroxyl radical(·OH)and superoxide radical(·O_(2)^(-))was detected and quantified by radical trapping experiments,to illustrating their key role in degrading MO molecules.In addition,we carried out sequential cycles to evaluate the cycling stability and usage durability of catalysts and a reduction of ~15% in the efficiency was observed after four cycles.This work provides a promising paradigm for the further development of piezo-photocatalytic materials and target applications in environmental field.
基金the National Key Research and Development Program of China(No.2022YFB3803600)the National Natural Science Foundation of China(Nos.52272244 and 51972288)+1 种基金the Fundamental Research Funds for the Central Universities(No.2652022202)2021 Graduate Innovation Fund Project of China University of Geosciences,Beijing(No.ZY2021YC006).
文摘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.
