Highly efficient and facile removal of As(V) from water by using Pb‐MOF with higher stable and fluorescence

Abstract

Metal–organic framework (MOF) materials are promising adsorbents for removing As(V) from sodium arsenate aqueous solutions, because of their high porosity and functional modulability. Two novel Pb(II) complexes {[Pb2(bcabsa)(μ2‐OH)]}n (Pb (bcabsa)) and {[Pb (Hbcabsa)]·(4,4′‐bpy)(H2O)}n (Pb (bcabsabpy)) (H3bcabsa = 4‐(N,N′‐bis(4‐carboxy benzyl)amino)benzene‐sulfonic acid, 4,4′‐bpy = 4,4′‐bipyridine), were hydrothermally synthesized. Pb (bcabsabpy) was characterized by single‐crystal X‐ray diffraction (SC‐XRD), X‐ray photoelectron spectroscopy (XPS), photoluminescence, powder X‐ray diffraction (XRD), and infrared radiation (IR) before and after the adsorption of As(V). In addition, the capacity of Pb (bcabsabpy) to remove arsenic was also investigated. The experimental results showed that Pb (bcabsabpy) had high stability within pH 4–12 and a relatively high As(V) removal rate (>90%) in the pH range of 4–10. The adsorption kinetics followed the pseudo‐second‐order kinetic model, whereas the adsorption isotherm was in agreement with the Langmuir equation. Pb (bcabsabpy) had a high adsorption capacity of As(V) in an aqueous solution (Qmax of 25.51 mg g−1). The fluorescence mechanism of the H3bcabsa, Pb (bcabsa), and Pb (bcabsabpy) are assigned to π‐π*, n‐π*, and π‐π* electron transition processes, respectively.