Fabrication and characterization of ternary composite MgFe2O4/MoO3@CNTs for the enhanced photocatalytic activity to degrade organic pollutants
Khadijah Mohammedsaleh Katubi, Amna Murtaza, Hafiz Muhammad Asif, Z.A. Alrowaili, M.S. Al-Buriahi, Sana Munir, Muhammad Farooq Warsi
Abstract
The recent industrial revolution and population growth have escalated the threat to the environment. Industries themselves discharge millions of tons of different harmful solvents, chemicals, and organic/metal ions into the water system each year. For the degradation of these organic wastes, photocatalysis has been extensively studied. The most researched classes of nanoparticles used as photocatalysts in environmental remediation are metal oxide and metal ferrite nanostructures. In this context, we have fabricated magnesium ferrite (MgFe 2 O 4 ) nanoparticles and molybdenum trioxide (MoO 3 ) nanorods by coprecipitation and hydrothermal processes, respectively. Moreover, their binary composite (MgFe 2 O 4 / MoO 3 ) was fabricated to improve the absorption of light in the visible region. Further, its ternary composite was fabricated with CNTs (MgFe 2 O 4 /MoO 3 @CNT) to enhance photocatalytic activity by reducing the recombination rate via trapping photoinduced species. X-rays diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic analysis were carried out for structural confirmation. From XRD data, the crystallite size and other crystallographic parameters of the fabricated samples were determined. The calculated crystallite sizes of MgFe 2 O 4 and MoO 3 were 12.74 nm and 31.36 nm, respectively. Band gap calculation and optical studies were done by UV–visible spectroscopy. The decrease in band gap value of MgFe 2 O 4 /MoO 3 leads to remarkable photocatalytic activity than bare photocatalysts. The photocatalytic performance of all photocatalysts was examined by degrading methyl orange (MO) dye, pendimethalin (PDM), and benzoic acid (BA). Comparative studies revealed that MgFe 2 O 4 /MoO 3 @CNT exhibited brilliant photocatalytic activity among the aforementioned photocatalysts. It degraded 96%, 82%, and 67% methyl orange (MO), pendimethalin (PDM), and benzoic acid (BA), respectively. This outstanding increase in photodegradation process was due to the movement of photoexcited species from the conduction band to CNTs, where it traps the photoexcited species and limits their chances of recombination. Overall, this research offers a fresh understanding of the effective utilization of the MgFe 2 O 4 /MoO 3 @CNT ternary composite as a high-performance photocatalyst to address environmental protection concerns when exposed to visible light.