Silver oxide doped iron oxide/alginate nanocomposite coated cotton cloth for selective catalytic reduction of potassium ferricyanide

Abstract

Silver oxide doped iron oxide (Ag₂O-Fe₂O₃) nanocatalyst was prepared and coated on cotton cloth (CC) as well as wrapped in sodium alginate (Alg) hydrogel. Ag₂O-Fe₂O₃ coated CC (Ag₂O-Fe₂O₃/CC) and Ag₂O-Fe₂O₃ wrapped Alg (Ag₂O-Fe₂O₃/Alg) were utilized as catalysts in reduction reaction of 4-nitrophenol (4-NP), congo red (CR), methylene blue (MB) and potassium ferricyanide (K₃[Fe(CN)₆]). Ag₂O-Fe₂O₃/CC and Ag₂O-Fe₂O₃/Alg were found to be effective and selective catalyst for the reaction of K₃[Fe(CN)₆]. Further amount of catalyst, K₃[Fe(CN)₆] quantity, amount of NaBH₄, stability of catalyst and recyclability were optimized for the reaction of K₃[Fe(CN)₆] reduction. Ag₂O-Fe₂O₃/Alg and Ag₂O-Fe₂O₃/CC were appeared to be the stable catalysts by maintaining high activity during recyclability tests showing highest reaction rate constants (k_app) of 0.3472 and 0.5629 min^-1, correspondingly. However, Ag₂O-Fe₂O₃/CC can be easily recovered as compared to Ag₂O-Fe₂O₃/Alg by simply removing from the reaction which is the main advantage of Ag₂O-Fe₂O₃/CC. Moreover, Ag₂O-Fe₂O₃/Alg and Ag₂O-Fe₂O₃/CC were also examined in real samples and found useful for K₃[Fe(CN)₆] reduction involving real samples. The Ag₂O-Fe₂O₃/CC nanocatalyst is a cost and time saving material for economical reduction of K₃[Fe(CN)₆] and environmental safety.

Keywords: Ag(2)O–Fe(2)O(3); Catalytic reduction; Cotton cloth; Hydrogel; Potassium ferricyanide.