Preparation, characterization of CoxMn1−xO2 nanowires and their catalytic performance for degradation of methylene blue

Abstract

CoxMn1−xO2 nanowires and microspheres (0.15 ⩽ x ⩽ 0.5) catalysts were synthesized, and their catalytic performance in oxidative degradation of methylene blue (MB) in water under oxygen air bubbles pumping was investigated. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and N2 adsorption–desorption techniques were used to characterize the structure, morphology and SBET of CoxMn1−xO2 nanostructures. Nucleation–dissolution–recrystallization and reduction migration species mechanism was suggested for the growth of the nanowires. The effect of molar ratios of reactants and morphology of products were investigated in terms of MB degradation. The catalyst characterization was performed by mass spectra, chemical oxygen demand (COD), total organic carbon (TOC), the Langmuir and Freundlich isotherms. The results revealed the CoxMn1−xO2 nanowires exhibited excellent catalytic efficiency for the degradation of MB than CoxMn1−xO2 microspheres.

Keywords

• CoxMn1−xO2
• Nanomaterials
• Hydrothermal
• Crystal growth
• Degradation