Z-type Bi 2 O 2 CO 3 /NH 2 -MIL-125(Ti) heterojunction for efficient photocatalytic degradation of tetracycline

The spherical heterojunction Bi 2 O 2 CO 3 /NH 2 -MIL-125(Ti)(BOC/NMLT) composite photocatalytic materials were prepared by hydrothermal method. Under simulated visible light conditions, Bi 2 O 2 CO 3 /NH 2 -MIL-125(Ti)-5 (BOC/NMLT-5) had the best degradation performance of tetracycline (TC), and the degradation rate of TC reached 85.6% within 90 min, which was 10.4 times and 3.2 times that of pure NMLT and Bi 2 O 2 CO 3 , respectively. The characterization results show that Bi 2 O 2 CO 3 /NH 2 -MIL-125(Ti)-5 has a larger specific surface area, a wider light corresponding range, and a higher electron–hole transfer efficiency than the monomer Bi 2 O 2 CO 3 . The results of free radical quenching experiments show that h + and · O 2 − are the main active substances for the degradation of TC by Bi 2 O 2 CO 3 /NH 2 -MIL-125(Ti)-5, and the Z-type electron transfer mechanism of TC degradation in BOC/NMLT system is proposed.