High-Performance Recyclable Magnetic CuFe_2–xCr_xO₄ Nanocatalysts for Facile Reduction of Nitrophenols and Photooxidative Degradation of Organic Dyes

Abstract

Remediating pollutants in water sources is essential for preserving and protecting our water resources. Water pollution can have severe environmental, economic, and public health consequences. Water scarcity for domestic purposes can eventually be addressed by improving wastewater management. In the present study, highly active and magnetically separable Cr-doped copper ferrites CuFe 2−x Cr x O 4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) were synthesized via a sol−gel technique and employed for the conversion of nitrophenols to aminophenols and photooxidative deterioration of various dyes such as methyl orange (MO), rhodamine B (RhB), and methylene blue (MB), as well as their ternary solution (RhB + MO + MB). Powder X-ray diffraction investigation indicates that the prepared phases are well indexed in the Fd3̅ m space group except for CuFe 2 O 4 , which crystallizes in the I4 1 /amd space group. The M−H hysteresis loop results support the ferromagnetic behavior of the nanophases, which makes them magnetically separable. The optical-band-gap energies of prepared nanostructures were found to be in the range of 1.70−1.39 eV, which makes them appropriate and reliable photocatalysts. CuFe 2 O 4 was found to be the most efficient nanocatalyst toward the conversion of nitrophenols to aminophenols, while CuCrFeO 4 showed a maximum degradation efficiency for the deterioration of dyes. The kinetic models correctly explain both reduction and photodegradation processes using pseudo-first-order kinetics. Further, several recyclability runs demonstrated that the nanocatalysts were extremely stable and reusable. This study reflects the possibility of employing mesoporous nanocatalysts for practical applications in the treatment of wastewater.

Structure-led manifestation of photocatalytic activity in magnetically recoverable spinel CuFe2O4 nanoparticles and its application in degradation of industrial effluent dyes under solar light

“…For instance, Aslam et al successfully synthesised sulphur-doped CuFe 2 O 4 nanoparticles via hydrothermal methods demonstrating an effective degradation of 15 ppm Rhodamine B under visible light. Improved photocatalytic activity was also demonstrated by Manhas et al by doping Cr on Fe site of CFNPs [12,13]. Sharma et al also reported the development of complex core-shell structure of ZnFe 2 O 4 CuFe 2 O 4 @SiO 2 using co-precipitation for efficient removal of Methylene Blue (MB) [14].…”