The photocatalytic degradation performance and mechanism of rod-like hollow derivatives from Co-doped MIL-68(In) under visible light

In this study, we synthesized a convenient and efficient composite photocatalyst, In 2 O 3 /Co 3 O 4 from the pyrolysis of Co-doped MIL-68(In). Structural characterization indicates that the composite material exhibited a rod-like hollow structure, thus increasing the specific surface area. Meanwhile, In 2 O 3 /Co 3 O 4 forms a PN heterojunction, which reduces the recombination rate of photogenerated hole-electron pairs. Moreover, the visible light absorption ability of this material is enhanced and it has good catalytic properties. Under visible light, the removal rate of tetracycline (TC) reaches 94% by the In 2 O 3 /Co 3 O 4 in 90 min, and the reaction constant is 0.02393 min −1 , which is 6.86 and 5.56 times of the single component In 2 O 3 and Co 3 O 4 , respectively. As shown by free radical quenching experiments and electron paramagnetic resonance (EPR) test, h + and •O 2 − play an important role in degrading TC into small molecule intermediates in the catalytic process.