Nanoscaled MnSnO2@CsPbBr3 quantum dots heterostructure photocatalyst as efficient organic pollutants degradation by peroxymonosulfate; DFT calculation

Abstract

In this work, we developed a promising photocatalyst in CsPbBr3 quantum dots (QDs) because of their exceptional optoelectronic characteristics. However, QDs applications in the field of photocatalysis were mainly hampered by their poor stability and insufficient charge transfer efficiency. Herein, a novel and efficient MnSnO2@CsPbBr3 (MSO@QDs) nanocomposite was first time effectively designed and synthesized by a wet impregnation method for peroxymonosulfate (PMS) activation under the light. The newly generated interface phase of QDs between MnSnO2 (MSO) showed great potential to improve light absorption, leading to effective separation and transfer of photoelectron-hole pairs. This novel nanocomposite MSO@QDs showed great Flurbiprofen (FL) removal efficiency under the PMS/Light system. It should be noted that this nanocomposite removed 85.74% of FL in just 70 min, which was almost 1.11 and 2.51 times greater than using pure QDs and pure MSO, respectively. Based on thorough measurements of structural analysis, Brunauer-Emmett-Teller (BET), UV-vis spectra, electrochemical impedance spectroscopy (EIS), transient photocurrent response, and a potential mechanism for organic pollutants degradation over MSO@QDs nanocomposite was envisioned. The principal reactive species of photoinduced holes (h+), i.e. O2˙−, SO4˙−, ˙OH, and non-radical (1O2) were characterized via scavengers’ technique and electron paramagnetic resonance (EPR) measurements. The highest photocatalytic performance for the removal of MO, MB, and IBU was demonstrated by MSO@QDs nanocomposite/PMS, revealing their excellent ability to remove organic pollutants through photo-oxidation. Furthermore, the developed nanocomposite exhibited good stability in an aqueous medium. According to computational investigation using the density functional theory (DFT) method, the site's higher Fukui index f0 value corresponds to a greater propensity to be attacked by reactive species. This work offers a fresh perspective on developing further high-efficiency, low-cost photocatalysts for wastewater treatment.