Polyethylene glycol capped copper ferrite porous nanostructured materials for efficient photocatalytic degradation of bromophenol blue

Abstract

Three different types (blank, annealed, and functionalized) of copper ferrite nanoparticles (CuFe₂O₄) were synthesized by the co-precipitation method. The CuFe₂O₄ NPs were characterized by Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Energy-dispersive X-ray spectroscopy (EDX) techniques. FTIR analysis confirmed that 3-APTES is successfully grafted on the surface of CuFe₂O₄ NPs. XRD results show the amorphous nature of blank CuFe₂O₄ NPs, and crystalline structure was observed for annealed and functionalized CuFe₂O₄ NPs. XRD results revealed that crystallite size ranges from 23.6 to 34.6 nm. SEM micrographs of blank CuFe₂O₄ NPs show the irregular shape and size of the nanostructure. The spherical and strongly linked structure was seen in the micrograph of functionalized CuFe₂O₄ NPs. EDX analysis revealed the nanostructure composed of Fe, Cu, O, and a small percentage of Si. The photocatalytic degradation efficiency of synthesized CuFe₂O₄ NPs was examined under UV irradiation in an aqueous medium against bromophenol blue (BPB) dye. The effect of different parameters such as irradiation time and pH on the photodegradation of BPB dye was studied by all three types of CuFe₂O₄ photocatalyst. Results show that the maximum photocatalytic degradation efficiency was observed for functionalized CuFe₂O₄ nanoparticles that degraded 98% of BPB dye in the acidic medium at pH = 1. The optimum contact time for dye degradation was 120 min by synthesized photocatalyst. Photodegradation performance of blank and annealed CuFe₂O₄ NPs is less than 90%. The synthesized CuFe₂O₄ NPs were recycled and reused, which shows good photocatalytic degradation efficiency up to 4 consecutive cycles. The kinetic model displayed that degradation reaction followed pseudo 1^st order kinetics. The blank, annealed, and functionalized CuFe₂O₄ NPs have turnover numbers of 10.7x10 (Mudhoo et al., 2019), 12.9x10 (Mudhoo et al., 2019), and 22.2x10 (Mudhoo et al., 2019) (kg^-1 sec^-1) accordingly. In conclusion, all results revealed the high efficiency of prepared photocatalyst for tested hazardous dye from wastewater and encouraged more work on photodegradation of organic pollutants from wastewater.

Keywords: Bromophenol blue; Copper ferrite; Nanoparticles; Photocatalytic degradation; Porous nanomaterials; Reusability.