In situ synthesis of visible-light-driven a-MnO2 nanorod/AgBr nanocomposites for increased photoinduced charge separation and enhanced photocatalytic activity

• Published in: Materials research bulletin Vol. 133; p. 111046
• Main Authors: Salari, Hadi, Hasan Hosseini, Hajar
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2021
• Subjects: a-MnO2/AgBr; Advanced oxidation processes; Dye degradation; Photocatalysis; Advanced oxidation processes; Dye degradation; Photocatalysis; a-MnO2/AgBr
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2020.111046

[Display omitted]
•The a-MnO2/AgBr photocatalyst exhibited high photocatalytic activity under visible light irradiation.•Coupling of AgBr nanoparticles enhanced the photo-activity of ɑ-MnO2.•The photo-generated holes, and hydroxyl radicals play vital role in photo decomposition of dye.•Photocataytic activity is ascribed to improved light absorption, efficient separation and transfer of charge carriers.
Novel a-MnO2/AgBr nanocomposite was synthesized successfully by simple template free metods. Hydrothermal method was applied for shape control fabrication of a-MnO2 and AgBr nanoparticles was loaded by precipitation. Prepared photocatalyststs were characterized physically and chemically by XRD, XPS, FTIR, Raman, EDX, PZC, BET, DRS, PL, PC, TEM and EIS to verify the a-MnO2/AgBr properties and structure. The photoactivity of the prepared photocatalysts was investigated under visible light. Different parameters on activity of visible light activated photocatalysts for methylene blue degradation were investigated and reaction mechanism was proposed based on quenching approach. The observation confirmed that a-MnO2/AgBr has high photocatalytic performance toward dye removal and degradation. The degradation kinetics followed pseudo first order kinetic model. It is found that a-MnO2/AgBr composite exhibits much higher photoactivity than a-MnO2. The high photocataytic activity based on DRS, PL and EIS is ascribed to improved light absorption, efficient separation and transfer of charge carriers through the a-MnO2/AgBr lattice. The PC experiments indicate that the combination of AgBr with a-MnO2 leads to the electron-hole recombination inhibition. The prepared photocatalysts exhibited excellent reusability capability which make them potentially useful in environmental remediation and management.