A novel Bi12O17Cl2/GO/Co3O4 Z-type heterojunction photocatalyst with ZIF-67 derivative modified for highly efficient degradation of antibiotics under visible light.

[Display omitted] • ZIF-67 derivative and GO co-modified enhanced the visible light catalytic performance of Bi 12 O 17 Cl 2. • Bi 12 O 17 Cl 2 /GO/Co 3 O 4 exhibits good activity, salt resistance, universality and water adaptability to antibiotics degradation. • A pH drift method measures the surface charge of Bi 12 O 17 Cl 2 /GO/Co 3 O 4. • The Z-scheme heterojunction photocatalytic mechanism for Bi 12 O 17 Cl 2 /GO/Co 3 O 4 is analyzed. • Three possible degradation pathways of levofloxacin by Bi 12 O 17 Cl 2 /GO/Co 3 O 4 are proposed. Levofloxacin (LVX) is difficult to be naturally degraded by microorganisms in water, and its residues in water will pose significant risks to human health and ecological environment. In this study, Bi 12 O 17 Cl 2 was used as the main body, Bi 12 O 17 Cl 2 /GO/Co 3 O 4 composite photocatalyst was prepared by pyrolysis of zeolitic imidazolate framework-67 (ZIF-67) combined with in-situ precipitation method and used to degrade LVX. A sequence of characterizations shows that addition of Co 3 O 4 and graphene oxide (GO) increases the visible light response range, improves the separation efficiency of photogenerated electrons and holes (e--h+) of photocatalyst, and thus improves the degradation efficiency of LVX. Under the optimal reaction conditions, the LVX degradation rate of Bi 12 O 17 Cl 2 /1.5GO/7.5Co 3 O 4 can reach 91.2 % at 120 min, and its reaction rate constant is the largest (0.0151 min−1), which is 2.17, 13.14 and 1.53 times that of Bi 12 O 17 Cl 2 , Co 3 O 4 and Bi 12 O 17 Cl 2 /7.5Co 3 O 4 , respectively, showing better photocatalytic performance. Simultaneously, the recycling stability of Bi 12 O 17 Cl 2 /1.5GO/7.5Co 3 O 4 was also verified. The capture experiments and electron EPR test results showed that superoxide radicals (•O 2 –) and photogenerated holes (h+) were the primary active substances in the reaction process. Finally, combined with HPLC-MS results, the photocatalytic degradation pathway of LVX was derived. This work will provide a theoretical basis for the design of Metal Organic Frameworks (MOFs)-derivative modified Bi 12 O 17 Cl 2 -based photocatalysts. [ABSTRACT FROM AUTHOR]