Adsorption of cadmium (II) ions by polyacrylonitrile-based activated carbon nanofibers/magnesium oxide as its adsorbents

Abstract

In this work, activated carbon nanofibers (ACNFs) from precursor polyacrylonitrile (PAN) and magnesium oxide (MgO) were prepared via electrospinning process. The morphological properties of the PAN/MgO - based ACNFs were characterized by using Scanning Electron Microscopy (SEM) and the specific surface area (SSA) were investigated using nitrogen adsorption, Brunauer - Emmett - Teller (BET) methods. Moreover, the functional groups were analyzed by using Fourier Transform Infrared (FTIR). Besides that, the sorption study has been conducted in order to determine the adsorption capacity between electrospun ACNFs/MgO, pristine ACNFs and granular activated carbon (GAC) towards cadmium (II) i ons. The results showed that the SSA of modified ACNFs (198.80 m 2 /g) is significantly higher compared to the precursor ACNFs (15.43 m 2 /g), however the SSA obtained is quite lower compared to the average theoretical value. SEM micrograph of pristine ACNFs depicted more compact nanofibers compared to aligned nanofibers with average diameter of 200 - 700 nm. Under batch adsorption study, it was found out that Cd(II) removal of both ACNFs and ACNFs/MgO is higher compared to the commercial GAC. It has been demonst rated that the adsorption capacity of both electrospun ACNFs (ACNFs/MgO and pristine ACNFs) is higher when compared to the adsorption capacity of commercial GAC towards Cd (II) ions.