Construction of Z-scheme heterojunction of (BiO)2CO3/ZnFe-LDH for enhanced photocatalytic degradation of tetracycline

•(BiO)2CO3/ZnFe-LDH photocatalyst was successfully prepared by a simple hydrothermal method.•The (BiO)2CO3/ZnFe-LDH composite showed higher photocatalytic activities than pure (BiO)2CO3 and ZnFe-LDH.•The composite has the optimal band gap, which is beneficial to the transportation of photo-generated carriers.•The photocatalyst can maintain an exceptional stability and remarkable reusability within successive five-cycle runs.•Two possible heterojunction mechanisms were discussed and the reliable one was obtained by the analysis of band structure. A novel (BiO)2CO3/ZnFe-LDH photocatalyst was fabricated via a simple hydrothermal method for degradation of tetracycline aqueous solution. Due to the unique band structures of (BiO)2CO3 and ZnFe-LDH, the combination of these two materials formed a Z-scheme heterojunction, which was conducive to the separation of photo-generated carriers. Through measuring the absorbance, it was found that the composite with 5% ZnFe-LDH has the optimal photocatalytic performance among all the samples. 98.09% of tetracycline (TC) was degraded after adsorption for 30 min and light irradiation for 90 min. In addition, the (BiO)2CO3/ZnFe-LDH composite displayed a remarkable reusability and stability in five successive runs. Based on the results of characterization and performance, a possible photocatalytic mechanism was proposed. This work would be helpful for the application of composites in the field of photocatalysis.