Vanadium oxides nanostructures for adsorption of Methylene blue, vehicle exhaust and soot of ink as low carbon applications

Abstract

In this study, V2O5 nanoparticles were synthesized via facile method by annealing ammonium meta vanadate at 450 °C for 1 h. The resulting nanoparticles were analyzed using X-ray diffractometer, scanning electron microscopy, and transmission electron microscopy to investigate their structural and morphological properties. The optical properties of the prepared samples were examined using UV–VIS spectrophotometry. The XRD measurements indicated an orthorhombic V2O5 structure with an average crystallite size of 21.34 nm as calculated using the Debye-Scherrer formula. The synthesized V2O5 nanoparticles showed a plate like rod structure with an average size around 55 nm through TEM and HRTEM analysis. The Urbach energy (Eu) of V2O5 was calculated to be 1.07ev. The V2O5 nano-adsorbents were tested for their effectiveness in the selective removal of MB from an aqueous medium, as well vehicle exhaust and soot of ink from non-aqueous media. During the adsorption process, the impact of several factors including time, adsorbent dose, and different initial concentrations were investigated. Equilibrium adsorption isotherms were evaluated using Langmuir and Freundlich equations. The Langmuir model was found to be a better fit for the adsorption equilibrium, with correlation coefficients of 0.915, 0.904, and 0.912 for MB, vehicle exhaust, and soot of ink, respectively. The experimental kinetic results of V2O5 were found to fit the pseudo-second-order model for both aqueous and non-aqueous media with a higher correlation factor indicating chemisorption during the adsorption process.