Porphyrin-functionalized non-magnetic steel slag as bifunctional nanozymes for colorimetric detection and photocatalytic degradation of tetracycline.

[Display omitted] Inspired by natural enzymes with various activities, controlling the catalytic activity of nanozymes through suitable strategies has received extensive attention. By modifying non-magnetic steel slag material (NMSS) with porphyrin, we developed a new kind of bifunctional nanozymes (NMSS-Por) with both simulated enzyme activity and photocatalytic activity. The NMSS-Por nanozymes exhibit outstanding colorimetric sensing and photodegradation performances, with a limit of detection (LOD) of 0.257 µM, 0.102 µM and 0.142 µM for tetracycline (TC), oxytetracycline, and doxycycline, while a removal rate of 79 % for TC after 60 min. Hydroxyl radical (·OH), positively charged hole (h⁺), singlet oxygen (¹O 2), and photogenerated electron transfer process play vital roles in both catalytic reactions. Besides, NMSS-Por nanozymes has excellent selectivity for TC detection and can also be used as promising photocatalysts for real water treatment. This work provides a new and promising strategy for the high value-added resource utilization of waste steel slag in environmental catalysis, which is in accordance with the sustainable development of green chemistry. [ABSTRACT FROM AUTHOR]