The rational configuration of built-in electric field(IEF)in heterogeneous materials can significantly optimize the band structure to accelerate the separation of photogenerated charge carriers.However,the strength mo...The rational configuration of built-in electric field(IEF)in heterogeneous materials can significantly optimize the band structure to accelerate the separation of photogenerated charge carriers.However,the strength modulation of IEF formed by various materials has an uncertain enhancing effect on the separation of photogenerated carriers.Herein,a mesoporous MIL-125(Ti)@BiOCl S-scheme heterojunction with controllable IEF is prepared by green photoreduction reaction to investigate the relationship between IEF,microstructure,and photocatalytic activity.Moreover,the corresponding results demonstrate the MIL-125(Ti)@BiOCl effectively regulates the IEF strength through controlling the concentration of ligand defects,thereby optimizing the band structure and improving the efficiency of photogenerated charge separation.The optimized IEF significantly enhances the photocatalytic degradation performance of mesoporous MIL-125(Ti)-3@BiOCl towards tetracycline,with a k value of 0.07 min^(–1),which are approximately 5.5 and 4.7 times greater than that of BiOCl(0.0127 min^(–1))and MIL-125(Ti)-3(0.015 min^(–1)).These findings provide a new pathway for regulating IEF within MOF-based heterojunctions,and offer new insights into the intrinsic correlations between defect structure,IEF,and photocatalytic activity.展开更多
Defect engineering is regarded as an effective strategy for enhancing gas-sensing performance in metal-organic frameworks(MOFs).However,precise control over defect types and their specific impact on gas-sensing proper...Defect engineering is regarded as an effective strategy for enhancing gas-sensing performance in metal-organic frameworks(MOFs).However,precise control over defect types and their specific impact on gas-sensing properties remains a significant challenge.Herein,we propose a representative water-treatment approach to induce and regulate different defect types in various MOFs.Comparative structural analysis of ZIF-8 and ZIF-67,differing in metal centers,before and after water treatment,reveals that water molecules disrupt metal-ligand bonds,leading to metal defects in ZIF-8 via metal detachment and ligand defects in ZIF-67 through partial ligand loss.Gas-sensing results demonstrate that defect concentrations and gas-sensing capabilities in MOFs can be effectively modulated by controlling water treatment time.Notably,the presence of metal defects enhances the NO_(2)response of ZIF-8(20 ppm)by 2.63 times,while ligand defects improve the C_(2)H_(4)response of ZIF-67(25 ppm)by 3.96 times.Additionally,metal defect formation in MOF-74 is evidenced by a 2.97-fold enhancement in its response to 100 ppm acetone.Density functional theory calculations confirm that the defect sites enhance gas adsorption and sensing performance.This study offers new insights into defect engineering in MOFs,expanding the potential of defect-engineered MOFs for diverse applications.展开更多
文摘The rational configuration of built-in electric field(IEF)in heterogeneous materials can significantly optimize the band structure to accelerate the separation of photogenerated charge carriers.However,the strength modulation of IEF formed by various materials has an uncertain enhancing effect on the separation of photogenerated carriers.Herein,a mesoporous MIL-125(Ti)@BiOCl S-scheme heterojunction with controllable IEF is prepared by green photoreduction reaction to investigate the relationship between IEF,microstructure,and photocatalytic activity.Moreover,the corresponding results demonstrate the MIL-125(Ti)@BiOCl effectively regulates the IEF strength through controlling the concentration of ligand defects,thereby optimizing the band structure and improving the efficiency of photogenerated charge separation.The optimized IEF significantly enhances the photocatalytic degradation performance of mesoporous MIL-125(Ti)-3@BiOCl towards tetracycline,with a k value of 0.07 min^(–1),which are approximately 5.5 and 4.7 times greater than that of BiOCl(0.0127 min^(–1))and MIL-125(Ti)-3(0.015 min^(–1)).These findings provide a new pathway for regulating IEF within MOF-based heterojunctions,and offer new insights into the intrinsic correlations between defect structure,IEF,and photocatalytic activity.
基金supported by the National Natural Science Foundation of China(52403320,22401062,92261204,22431005)the Hainan Provincial Natural Science Foundation(522RC612)the Innovational Fund for Scientific and Technological Personnel of Hainan Province(KJRC2023C10)。
文摘Defect engineering is regarded as an effective strategy for enhancing gas-sensing performance in metal-organic frameworks(MOFs).However,precise control over defect types and their specific impact on gas-sensing properties remains a significant challenge.Herein,we propose a representative water-treatment approach to induce and regulate different defect types in various MOFs.Comparative structural analysis of ZIF-8 and ZIF-67,differing in metal centers,before and after water treatment,reveals that water molecules disrupt metal-ligand bonds,leading to metal defects in ZIF-8 via metal detachment and ligand defects in ZIF-67 through partial ligand loss.Gas-sensing results demonstrate that defect concentrations and gas-sensing capabilities in MOFs can be effectively modulated by controlling water treatment time.Notably,the presence of metal defects enhances the NO_(2)response of ZIF-8(20 ppm)by 2.63 times,while ligand defects improve the C_(2)H_(4)response of ZIF-67(25 ppm)by 3.96 times.Additionally,metal defect formation in MOF-74 is evidenced by a 2.97-fold enhancement in its response to 100 ppm acetone.Density functional theory calculations confirm that the defect sites enhance gas adsorption and sensing performance.This study offers new insights into defect engineering in MOFs,expanding the potential of defect-engineered MOFs for diverse applications.
