Stable photodegradation of antibiotics by the functionalized 3D-Bi2MoO6@MoO3/PU composite sponge: High efficiency pathways, optical properties and Z-scheme heterojunction mechanism

The designation and fabrication of heterogeneous photocatalyst with superior redox capability is an important technique for emerging pollutants treatment. In this study, we designed the Z-scheme heterojunction of stable 3D-Bi 2 MoO 6 @MoO 3 /PU, which could not only accelerate the migration and separation in photogenerated carriers, but also stabilize the separation rate of photo-generation carriers. In the Bi 2 MoO 6 @MoO 3 /PU photocatalytic system, 88.89% of oxytetracycline (OTC, 10 mg L −1 ) and 78.25%–84.59% of multiple antibiotics (SDZ, NOR, AMX and CFX, 10 mg L −1 ) could be decomposed within 20 min under the optimized reaction condition, revealing the superior performance and potential application value. Specifically, the morphology, chemical structure and optical properties detection of Bi 2 MoO 6 @MoO 3 /PU greatly affected the direct Z-scheme electron transferring mode in the p-n type heterojunction. Besides, the ·OH, h + , ·O 2 − dominated the photoactivation process through ring-opening, dihydroxylation, deamination, decarbonization and demethylation in OTC decomposition. Expectantly, the stability and universality of Bi 2 MoO 6 @MoO 3 /PU composite photocatalyst would further broaden the practical application and demonstrated that the potential of photocatalytic technique in antibiotics pollutants for wastewater remediation.