Microwave-assisted rapid growth of corncob-like nano-Ag2O/ZIF-8 on PAN electrospinning nanofibers enabled highly efficient selective adsorption desulfurization

Abstract

The higher energy consumption and processing cost greatly constricted the extensive application of the adsorption desulfurization technique. Herein, the nano-Ag2O/ZIF-8@ polyacrylonitrile (PAN) nanofiber membrane (NFM) was successfully made by using electrospinning and microwave-assisted synthesis. The characterizations demonstrated that the nano-Ag2O-dotted ZIF-8 with the exclusive corncob-like structure uniformly grew on the surface of PAN nanofiber. The in-situ fabrication of nano-Ag2O/ZIF-8 on the surface of PAN nanofiber was rapidly realized by microwave-assisted method, thus resulting in the less loss of the mechanical performance of NFM. The tests indicated that the tensile strength and young's modulus of Ag2O/ZIF-8@PAN NFM were 35 % and 185 % higher than PAN NFM, respectively. The fabrication of the multi-pore structure endowed the Ag2O/ZIF-8@PAN NFM to achieve the superior adsorption performance for thiophene (TH) from fuel oil, having the increase by 312 % and 175 % in the batch adsorption (maximum: 37.142 mg·g−1) and fixed-bed breakthrough adsorption (maximum: 35.423 mg·g−1) capacities compared to PAN NFM, respectively. Furthermore, the saturated adsorption capacity of Ag2O/ZIF-8@PAN NFM in fixed-bed adsorption experiment was higher than those of Cu2O-doped PAN NFM (4.571 mg·g−1) and Ag2O@HNTs-doped PAN NFM (31.982 mg·g−1) reported by our previous study. The adsorption mechanism of TH molecules on the Ag2O/ZIF-8@PAN NFM was explored by the kinetics, intra-particle diffusion, isotherms and thermodynamic models, which affirmed to exist the synergistic effect of physical adsorption, and chemical adsorption including π-complexation interaction and S-M interaction adsorption. Finally, this work provided a novel prospective adsorption desulfurization based on the membrane separation.