Two-dimensional π–d conjugated metal–organic framework Fe3(hexaiminotriphenylene)2 as a photo-Fenton like catalyst for highly efficient degradation of antibiotics

Fenton and Fenton-like reaction are mainly limited by the low efficiency due to the sluggish Fe(II)/Fe(III) cycle. Herein, the Fe(II)/Fe(III) cycle is greatly promoted taking advantage of the high conductivity and wide spectral absorption of a two-dimensional (2D) π-d conjugated metal-organic framework (MOF) Fe3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene). Fe3(HITP)2 exhibits superior catalytic performance (ca. 96.7 %) and total organic carbon (TOC) removal percentage (62.7 %) towards the photo-Fenton like degradation of tetracycline (TC) within 30 min under visible light illumination. Fe3(HITP)2 also displays excellent stability, the degradation performance of which slightly changes in a wide pH range (pH = 3–9). The concentration of iron leached from Fe3(HITP)2 (0.037 mg/L) is much lower than those reported before, avoiding the generation of secondary pollution. Moreover, Fe3(HITP)2 also displays prominent catalytic performance in the degradation of other antibiotics and industrial wastewater, suggesting its high potential in industrial application. Light irradiation is proved to promote the dynamic cycle of Fe(II)/Fe(III). This work suggests that Fe3(HITP)2 holds great potential in solving environmental problems, and provides an alternative approach to design stable and efficient Fenton like catalysts.