A synergistic strategy to remove hazardous water pollutants by mimicking burdock flower morphology structures of iron oxide phases. (January 2022)

• Record Type: Journal Article
• Authors: Koli, Rohit R.; Deshpande, Nishad G.; Kim, Dong Su; Cho, Hyung Koun
• Is Part Of: Chemosphere. Volume 286:Part 2(2022)
• Publication Date: 2022-01
• Subjects: Iron oxide -- Biomimetic burdock flower -- Photocatalyst -- Dye adsorbent -- Dual filter; C-black carbon black -- EG ethylene glycol -- NaOAc sodium acetate -- FG ferrous glycolate -- FGR ferrous glycolate sub-microrods -- FGU ferrous glycolate (closed burdock structure) -- hFU hollow α-Fe2O3 (annealed at 400 °C)-open burdock flower -- hFU600 Faded α-Fe2O3 (annealed at 600 °C) -- hFUN2 Fe3O4@C (annealed in N2 at 400 °C)-open burdock flower -- hFU600N2 Fe3O4(annealed in N2 at 600 °C)-faded burdock structure -- MNPs magnetic nanoparticles -- NSPs nanospheres -- SMPs sub-microspheres -- MW microwaves -- ST solvothermal -- PDI polydispersity index -- R bubble rise rate -- MB Methylene blue -- CR Congo Red -- RB Rhodamine B -- MO Methyl Orange; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131789
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Artificially mimicking structures/morphologies available in the nature to develop multifunctional materials for catalysis is receiving greater attention. Particularly, the burdock flower morphology, which has a hollow-globe surrounded by spiky sheets, represents a multifunctional structure helpful in adsorption as well as intercalation of molecules. Given this, we have strategically developed a robust microwave (MW) bubble-template process to achieve highly uniform α-Fe2 O3 and carbon-enriched Fe3 O4 (Fe3 O4 @C) phases resembling the characteristics of spiky hollow burdock morphologies. The utilization of the MW bubble-templates as a pretreatment to the iron-based precursor solution helps in producing hollowed open-space ferrous glycolate burdock flower morphology with rapid production rate and without any addition of extra agents. Such burdock flower structures remain intact even after annealing in air/N2 ambiance providing highly photoactive α-Fe2 O3 or magnetic Fe3 O4 @C, respectively. Utilizing the hollow burdock flower structures together with the individual photo/magnetic properties of iron oxide phases, a dual-layer filter was designed to remove hazardous dye molecules from water, which efficiently photodegraded (99.2 %) in natural sunlight as well as showed excellent adsorption (99.7 %) within minutes. Comparatively, a lower catalytic activity using simple iron oxide nanoparticles, closed, and faded burdock morphologies were seen. Hence, the high catalytic activity in removing the dye molecules, retention of structural phases after repeated use, and strong durability were a result of the synergetic effect of photo/magnetic properties, activated surface/spiky open burdock structure. Graphical abstract: Polymerized growth of FG nanoflakes on MW-induced glycol bubble templates.Their smooth transitions towards α-Fe2 O3 (photocatalyst) and Fe3 O4 @C (efficient adsorbent) hollowmicrourchins under suitable annealing conditions. Inset: (Right) shows structural/morphological transformation of product with concentration/MW-dose. Image 1