Promoting photo-Fenton catalytic performance of MnFeO3-type perovskite via creation of type-II heterojunction with superior charge separator boron nitride quantum dots

In this work, boron nitride quantum dots (BNQDs) were successfully embedded on ferrite-type perovskite MnFeO3 (MFO) structure by facile impregnation method to generate MFO/BNQDs heterojunctions. The as-synthesized photocatalysts were characterized by SEM–EDS, TEM, XRD, XPS, EIS and photocurrent techniques. The occupation of oxygen atoms by nitrogen and boron elements was observed in XPS analysis which confirmed the presence of BNQDs over the perovskite. Introducing BNQDs into the structure enhanced the optical properties of bare MFO namely facilitated separation and transfer efficiency of charge carriers by creation Type–II heterojunction system. Likewise, the presence of BNQDs enhanced light absorptivity towards a longer wavelength which lowered bandgap energy. Under visible light assisted Fenton process, the heterojunctions demonstrated higher catalytic performance against tetracycline hydrochloride antibiotic and the rate constant of MFO/BNQDs was calculated 1.9 times greater than bare MFO. Radical trapping experiments revealed that the holes were the main dominant species in the degradation mechanism and BNQDs played active roles due to their hole extraction ability. Furthermore, the feasibility of the MFO/BNQDs system was confirmed in different aquatic media such as sea, lake and tap waters. The degradation pathway was suggested according to the intermediate analysis after reaction. Towards this direction, this work could ensure a valuable perspective for enhancing the photocatalytic activity of MnFeO3 by constructing with BNQDs.