| Autor: |
Chaves NO; Postgraduate Program in Materials Science and Engineering (P2CEM), Federal University of Sergipe, São Cristovão 49100-000, SE, Brazil., Lima LS; Laboratory of Corrosion and Nanotechnology (LCNT), Federal University of Sergipe, São Cristovão 49100-000, SE, Brazil., Monteiro MDS; Laboratory of Corrosion and Nanotechnology (LCNT), Federal University of Sergipe, São Cristovão 49100-000, SE, Brazil., Sobrinho RAL; Department of Chemical Engineering, State University of Santa Cruz, Rod. Jorge Amado, Km 16-Salobrinho, Ilhéus 45662-900, BA, Brazil., Ferreira NS; Department of Physics, Federal University of Sergipe, São Cristovão 49100-000, SE, Brazil., Ramos GQ; Centro Multiusuário para Análise de Fenômenos Biomédicos, Universidade do Estado do Amazonas, Manaus 69410-000, AM, Brazil., da Fonseca Filho HD; Laboratory of Synthesis of Nanomaterials and Nanoscopy (LSNN), Physics Department, Federal University of Amazonas-UFAM, Manaus 69077-000, AM, Brazil., Oliveira RMPB; Postgraduate Program in Materials Science and Engineering (P2CEM), Federal University of Sergipe, São Cristovão 49100-000, SE, Brazil., Matos RS; Amazonian Materials Group, Federal University of Amapá (UNIFAP), Macapá 68911-477, AP, Brazil. |
| Abstrakt: |
Blast furnace dust waste (BFDW) proved efficient as a photocatalyst for the decolorization of methylene blue (MB) dye in water. Structural analysis unequivocally identified α-Fe 2 O 3 as the predominant phase, constituting approximately 92%, with a porous surface showcasing unique 10-30 nm agglomerated nanoparticles. Chemical and thermal analyses indicated surface-bound water and carbonate molecules, with the main phase's thermal stability up to 900 °C. Electrical conductivity analysis revealed charge transfer resistance values of 616.4 Ω and electrode resistance of 47.8 Ω. The Mott-Schottky analysis identified α-Fe 2 O 3 as an n-type semiconductor with a flat band potential of 0.181 V vs. Ag/AgCl and a donor density of 1.45 × 10 15 cm -3 . The 2.2 eV optical bandgap and luminescence stem from α-Fe 2 O 3 and weak ferromagnetism arises from structural defects and surface effects. With a 74% photocatalytic efficiency, stable through three photodegradation cycles, BFDW outperforms comparable waste materials in MB degradation mediated by visible light. The elemental trapping experiment exposed hydroxyl radicals (OH•) and superoxide anions (O2-•) as the primary species in the photodegradation process. Consequently, iron oxide-based BFDW emerges as an environmentally friendly alternative for wastewater treatment, underscoring the pivotal role of its unique physical properties in the photocatalytic process. |
