Self-assembled Bi2SeO5/rGO/MIL-88A Z-scheme heterojunction boosting carrier separation for simultaneous removal of Cr (VI) and chloramphenicol

The simultaneous elimination of organic pollutant and heavy metals using efficient catalysts has attracted much attentions, but facing obstacles of low redox ability and high recombination rate of photogenerated carriers. Herein, we have successfully synthesized Bi2SeO5/rGO/MIL-88A composition for the synergistic photocatalytic removal of chloramphenicol (CAP) and Cr6+. The optimal sample can concurrently remove 85.68% of CAP and 91.85% of Cr6+ in 120 min. The enhanced performance is attributed to that Z-scheme heterojunction formed between metal compounds, which accelerates the separation of electrons and holes. Notably, the hybrid of rGO is proved to facilitate the flow of electrons and significantly inspire the nitrogen reduction (59.34% of N is reduced into ammonia). Furthermore, the mineralization and denitrification pathway of CAP are proposed based on calculation and experiment. Our study integrates reduction, degradation and denitrification innovatively, providing a new insight for simultaneous removal of heavy metal and nitrogenous organic pollutant.

Automated summary

The study synthesized a Bi2SeO5/rGO/MIL-88A composite for the simultaneous removal of chloramphenicol and hexavalent chromium, enhancing efficiency by accelerating the separation of electrons and holes. The hybrid was found to facilitate nitrogen reduction.