Designing photocatalysts with high light utilization and efficient photogenerated carrier separation for pollutant degradation is one of the important topics for sustainable development.In this study,hierarchical core...Designing photocatalysts with high light utilization and efficient photogenerated carrier separation for pollutant degradation is one of the important topics for sustainable development.In this study,hierarchical core–shell materialα-Fe_(2)O_(3)@ZnIn_(2)S_(4)with a step-scheme(S-scheme)heterojunction is synthesized by in situ growth technique,and MXene Ti_(3)C_(2)quantum dots(QDs)are introduced to construct a double-heterojunction tandem mechanism.The photodegradation efficiency ofα-Fe_(2)O_(3)@ZnIn_(2)S_(4)/Ti_(3)C_(2)QDs to bisphenol A is 96.1%and its reaction rate constant attained 0.02595 min^(−1),which is 12.3 times that of pureα-Fe_(2)O_(3).Meanwhile,a series of characterizations analyze the reasons for the enhanced photocatalytic activity,and the charge transport path of the S-scheme heterojunction/Schottky junction tandem is investigated.The construction of the S-scheme heterojunction enables the photo-generated electrons ofα-Fe_(2)O_(3)and the holes of ZnIn2S4 to transfer and combine under the action of the reverse built-in electric field.Due to the metallic conductivity of Ti_(3)C_(2)QDs,the photogenerated electrons of ZnIn_(2)S_(4)are further transferred to Ti_(3)C_(2)QDs to form a Schottky junction,which in turn forms a double-heterojunction tandem mechanism,showing a remarkable charge separation efficiency.This work provides a new opinion for the construction of tandem double heterojunctions to degrade harmful pollutants.展开更多
基金supported by the National Natural Science Foundation of China(No.21771061)Outstanding Youth Fund of Heilongjiang Province(No.JQ 2020B002).
文摘Designing photocatalysts with high light utilization and efficient photogenerated carrier separation for pollutant degradation is one of the important topics for sustainable development.In this study,hierarchical core–shell materialα-Fe_(2)O_(3)@ZnIn_(2)S_(4)with a step-scheme(S-scheme)heterojunction is synthesized by in situ growth technique,and MXene Ti_(3)C_(2)quantum dots(QDs)are introduced to construct a double-heterojunction tandem mechanism.The photodegradation efficiency ofα-Fe_(2)O_(3)@ZnIn_(2)S_(4)/Ti_(3)C_(2)QDs to bisphenol A is 96.1%and its reaction rate constant attained 0.02595 min^(−1),which is 12.3 times that of pureα-Fe_(2)O_(3).Meanwhile,a series of characterizations analyze the reasons for the enhanced photocatalytic activity,and the charge transport path of the S-scheme heterojunction/Schottky junction tandem is investigated.The construction of the S-scheme heterojunction enables the photo-generated electrons ofα-Fe_(2)O_(3)and the holes of ZnIn2S4 to transfer and combine under the action of the reverse built-in electric field.Due to the metallic conductivity of Ti_(3)C_(2)QDs,the photogenerated electrons of ZnIn_(2)S_(4)are further transferred to Ti_(3)C_(2)QDs to form a Schottky junction,which in turn forms a double-heterojunction tandem mechanism,showing a remarkable charge separation efficiency.This work provides a new opinion for the construction of tandem double heterojunctions to degrade harmful pollutants.
