Morphology evolution of Fe-doped V2O5 flower-like microspheres for H2S adsorption

Abstract

Vanadium pentoxides (V₂O₅) are commonly employed as adsorbents for hydrogen sulfide (H₂S). Their adsorption capacity can be enhanced by doping with transition metal oxides and/or morphology modification. This paper aims to study the morphology evolution of Fe-doped V₂O₅ flower-like microspheres for H₂S adsorption. The morphology and structure of Fe-doped V₂O₅ were characterized using FE-SEM, XRD, XPS, Raman, FTIR and XRF mapping analyses. The H₂S adsorption capacity was evaluated by passing a mixture of H₂S and N₂ gas through a test tube containing the Fe-doped V₂O₅ material, and the H₂S concentration in the output was measured with a detector to determine the adsorption capacity of the sample. At optimal doping concentration of 0.2 mmol Fe, perfect Fe-doped V₂O₅ flower-like with an average diameter of 4.5 μm and BET of 7.2 m²/g was achieved, which yielded maximum H₂S adsorption capacity of 2.24 mg/g and removal efficiency of 87%. Fe dopant ions partially replaced vanadium sites within the V₂O₅ lattice, leading to the formation of additional oxygen vacancies and there by improving the overall surface reactivity, enhancing its H₂S adsorption capacity. However, excessive Fe doping resulted in the formation of hollow structure and secondary Fe₂V₄O₁₃ phases, which altered the chemical structure of V₂O₅, partially blocked active sites and diminished the adsorption capability of the material. These findings demonstrate the potential of Fe-doped V₂O₅ flower-like as an efficient and energy-saving material for H₂S removal at room temperature.