Bi5O7I supported chitosan nanocomposite a robust, highly efficient, and sustainable catalyst for methyl orange pand 4-nitrophenol reduction.

Abstract

Chitosan (CS) has garnered significant attention as catalyst support due to its abundance, eco-friendliness, and renewable nature, making it a highly sustainable option in catalytic applications. We report herein a new simple and eco-friendly strategy to stabilize Bi₅O₇I nanosheets within CS-hydrogel and their immobilization in catalytic applications. The Bi₅O₇I nanosheets were firstly prepared through a solvothermal process and then stabilized within CS-hydrogel beads through a simple co-precipitation in alkaline media. The prepared Bi₅O₇I nanosheets and Bi₅O₇I@CSb composite were fully characterized by X-ray diffraction, XPS, SEM, EDS, TGA, FTIR, Raman, and Zeta-potential. Photodegradation experiments of methyl orange (MO) over Bi₅O₇I@CSb in aqueous media exhibit a high performance with a removal efficiency of up to 97 % within 120 min. Likewise, the Bi₅O₇I@CSb composite demonstrated a high reduction efficiency toward 4-nitrophenol (4-NP) reduction up total conversion within only 3 min using NaBH₄ as a reducing agent. More importantly, the Bi₅O₇I@CSb composite could easily be recovered from the reaction mixture by simple filtration with no significant loss of their activity and stability even after 7 and 10 successive uses for both MO and 4-NP, respectively. Thus, this contribution may offer a great opportunity for the use of CS bismuth-based materials in catalytic and photocatalytic wastewater treatment.