Fenton-like nanocatalyst for photodegradation of methylene blue under visible light activated by hybrid green DNSA@Chitosan@MnFe2O4

Abstract

High efficient 3,5-Dinitrosalicylic acid/Chitosan/MnFe₂O₄ (DNSA@CS@MnFe₂O₄) nano photocatalyst was prepared to enrich both adsorption and photodecomposition under visible light. This paper focused on the importance of DNSA@CS as an excellent connector between methylene blue (MB) and MnFe₂O₄ for accelerating photodegradation with the encouragement of photo-Fenton catalytic reagent hydrogen peroxide (H₂O₂). The optimum conditions were: contact time, 30 min, H₂O₂ concentration, 0.16 M, pH factor 9 and dosage 0.06 g/l at R.T, allowing excellent catalytic achievements 98.9% degree of decolorization in 30 min. More interestingly, the hybrid DNSA@CS@MnFe₂O₄ mechanism explained on the basis of coexistence of Mn²⁺/Mn³⁺ and Fe³⁺/Fe²⁺ redox couples during the reaction. The photocatalytic decolorization experimentally affirmed the suitability of DNSA@CS@MnFe₂O₄ obeying Langmuir-Hinshelwood model. Also, the nano-catalytic system was stable even after five runs. The prepared nanostructured catalyst provides simple fabrication to promote deep understand criteria for the mechanistic role of MnFe₂O₄ catalyst for degradation of MB molecules.

Keywords: Adsorption; Chitosan; MnFe(2)O(4); Photo-Fenton; Photodegradation.