Adsorption and sunlight-induced photocatalytic degradation of methyl blue by BaFe12O19 ferrite particles synthesised through co-precipitation method

Abstract

ABSTRACT BaFe12O19 (BaM) hexagonal ferrite was synthesised through the co-precipitation route. The thermal decomposition behaviour of co-precipitated powder was studied by DSC-TG. XRD and Raman analysis confirmed the formation of pure BaM phase at 900°C calcination temperature. Morphological analysis was done using FESEM. The magnetic behaviour of BaM was analysed using a vibrating sample magnetometer. The saturation magnetisation (Ms) of 67.7 emu g−1 and coercivity of 5106 Oe was observed in BaM. BaM ferrite with a surface area of 8.2 m2 g−1 was used for the adsorption of methyl blue (MB) and sunlight-induced photodegradation. The optical band gap of the ferrite was ~2.9 eV. The adsorption process followed the pseudo-second-order model and satisfied Langmuir adsorption isotherm. BaM particles showed the maximum Langmuir saturation adsorption ability of 223.86 mg g−1 at an initial MB solution pH of 5.7. The free energy and enthalpy changes of the adsorption confirmed the spontaneous and exothermic nature of the process. About 73% of degradation of MB was found within 3 h of sunlight-induced photocatalytic degradation. Reproduced BaM powder showed high adsorption and degradation efficiency even after five cycles. All these results suggest that BaM particles can be used as a promising material for the adsorption and degradation of MB in wastewater treatment.