Construction of Z-scheme Ag-AgBr/Bi2O2CO3/CNT heterojunctions with remarkable photocatalytic performance using carbon nanotubes as efficient electronic mediators.

Abstract

It is a useful strategy to use a solid electronic mediator with good conductivity to assist the separation of semiconductor photo-induced electron-hole pairs and the redox of semiconductor materials. In order to construct a photocatalyst for more efficient photocatalytic degradation of antibiotics, a simple hydrothermal and precipitation method was used to construct the Ag-AgBr/Bi2O2CO3/CNT Z-scheme heterojunction by using carbon nanotubes (CNTs) as electronic mediators. Compared with the pristine AgBr, Bi2O2CO3, Bi2O2CO3/CNT, the 30%Ag-AgBr/Bi2O2CO3/CNT photocatalyst has better photocatalytic activity under visible light irradiation, showing the best degradation ability to tetracycline (TC). Meanwhile, the photocatalytic properties of 30%Ag-AgBr/Bi2O2CO3/CNT in different pH and inorganic ions were studied. Finally, the degradation pathway and catalytic mechanism of 30%Ag-AgBr/Bi2O2CO3/CNT photocatalytic degradation of TC were also argued. The construction of the Z-scheme electron transport pathway, in which CNTs were used as electronic mediators, and the SPR effect of Ag and Bi metal, which enable the effective separation and transfer of photo-generated electron-hole pairs, are responsible for the significant improvement in photocatalytic performance. It opens up new possibilities for designing and developing high-efficiency photocatalysts with CNTs as the electronic mediator.