Although defect engineering has been widely used to boost catalytic CO_(2) photoreduction,the piezoelectric polarized properties induced by structure changes through introducing defects are always ignored.Here we repo...Although defect engineering has been widely used to boost catalytic CO_(2) photoreduction,the piezoelectric polarized properties induced by structure changes through introducing defects are always ignored.Here we report a new kind of bismuth oxybromide(BiOBr,BOB)with piezoelectric property regulated by oxygen vacancies(OVs).Compared with pure BOB,BOB with OVs(BOB-OV)could enhance photocatalytic CO_(2) reduction efficiency under the ultrasonic force,achieving durable CO_(2) reduction process to superior production rates of CO(54.4μmol g^(-1) h^(-1))with a high selectivity(92%).Moderate OVs concentration changed the degree of Bi-Br stretching in the BOB-OV to produce strong dipole moments,which endowed BOB-OV with strong spontaneous piezoelectric polarization ability under external force.Ultrasonic piezoelectric effects were innovatively integrated into the photocatalytic reaction,which not only provided an alternating force field to modulate the spontaneous polarization of BOB-OV,thereby maintaining efficient photogenerated charge separation,but also lowered the reaction energy barrier of CO_(2) by high stress,ultimately improving CO product selectivity.This study is the first to leverage OVs-induced piezoelectric polarization effects to enhance the performance and product selectivity of photocatalytic CO_(2) reduction,providing new directions and insights for defect engineering to contribute to photocatalysis.展开更多
The adsorption of peroxymonosulfate(PMS)is crucial for PMS activation in the heterogeneous advanced oxidation processes.However,the investigation of PMS adsorption on the piezocatalysts still remains insufficient.In t...The adsorption of peroxymonosulfate(PMS)is crucial for PMS activation in the heterogeneous advanced oxidation processes.However,the investigation of PMS adsorption on the piezocatalysts still remains insufficient.In this work,bismuth oxychloride(BiO Cl)nanosheets were prepared as the piezocatalysts for PMS activation under ultrasonic vibration to remove carbamazepine(CBZ)in aqueous solutions.Up to92.5%of CBZ was degraded for 40 min in Bi OCl piezo-activated PMS system with the reaction rate constant of 0.0741 min-1,being 1.63 times that of the sum of BiOCl piezocatalysis,BiOCl-activated PMS,and vibration-activated PMS.PMS adsorption on the surface of BiOCl was specifically studied by comparing the microscopic structure change of the fresh and used Bi OCl.The results suggested that the piezoelectric field of Bi OCl was able to promote the tight adsorption of PMS on the surface,thus facilitating the fast activation of PMS through electrons transfer to produce reactive species(HO·,SO_(4)·-,O_(2)·-,1O_(2)).This work presents an in-depth understanding for the role of piezoelectric effect on the adsorption and activation of PMS.展开更多
文摘Although defect engineering has been widely used to boost catalytic CO_(2) photoreduction,the piezoelectric polarized properties induced by structure changes through introducing defects are always ignored.Here we report a new kind of bismuth oxybromide(BiOBr,BOB)with piezoelectric property regulated by oxygen vacancies(OVs).Compared with pure BOB,BOB with OVs(BOB-OV)could enhance photocatalytic CO_(2) reduction efficiency under the ultrasonic force,achieving durable CO_(2) reduction process to superior production rates of CO(54.4μmol g^(-1) h^(-1))with a high selectivity(92%).Moderate OVs concentration changed the degree of Bi-Br stretching in the BOB-OV to produce strong dipole moments,which endowed BOB-OV with strong spontaneous piezoelectric polarization ability under external force.Ultrasonic piezoelectric effects were innovatively integrated into the photocatalytic reaction,which not only provided an alternating force field to modulate the spontaneous polarization of BOB-OV,thereby maintaining efficient photogenerated charge separation,but also lowered the reaction energy barrier of CO_(2) by high stress,ultimately improving CO product selectivity.This study is the first to leverage OVs-induced piezoelectric polarization effects to enhance the performance and product selectivity of photocatalytic CO_(2) reduction,providing new directions and insights for defect engineering to contribute to photocatalysis.
基金financially supported by the National Natural Science Foundation of China(No.22006052)the Science and Technology Program of Guangzhou,China(No.202201020545)。
文摘The adsorption of peroxymonosulfate(PMS)is crucial for PMS activation in the heterogeneous advanced oxidation processes.However,the investigation of PMS adsorption on the piezocatalysts still remains insufficient.In this work,bismuth oxychloride(BiO Cl)nanosheets were prepared as the piezocatalysts for PMS activation under ultrasonic vibration to remove carbamazepine(CBZ)in aqueous solutions.Up to92.5%of CBZ was degraded for 40 min in Bi OCl piezo-activated PMS system with the reaction rate constant of 0.0741 min-1,being 1.63 times that of the sum of BiOCl piezocatalysis,BiOCl-activated PMS,and vibration-activated PMS.PMS adsorption on the surface of BiOCl was specifically studied by comparing the microscopic structure change of the fresh and used Bi OCl.The results suggested that the piezoelectric field of Bi OCl was able to promote the tight adsorption of PMS on the surface,thus facilitating the fast activation of PMS through electrons transfer to produce reactive species(HO·,SO_(4)·-,O_(2)·-,1O_(2)).This work presents an in-depth understanding for the role of piezoelectric effect on the adsorption and activation of PMS.
