Maghemite and Graphene Oxide Embedded Polyacrylonitrile Electrospun Nanofiber Matrix for Remediation of Arsenate Ions

Contamination of surface water by extremely poisonous arsenic (As) species due to indiscriminant disposal of industrial and mining waste is a serious concern worldwide. Considering the above apprehension, maghemite (γ-Fe2O3) and graphene oxide (GO) embedded in a polyacrylonitrile (PAN) polymer nanofiber matrix (PAN/GO/γ-Fe2O3) was successfully fabricated by electrospinning technique. Successful incorporation of γ-Fe2O3 and GO into the PAN polymer matrix via the electrospinning process was investigated by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Raman analytical techniques. Magnetic and thermal properties of the prepared nanofibers were studied by vibrating sample magnetometer (VSM) and thermogravimetry–derivative thermogravimetry (TG-DTG) analysis. The specific surface area of the prepared adsorbent was found to be 30.24 m2/g, which was determined by Brunauer, Emmett, and Teller (BET) analysis. Batch adsorption experiments were conducted to study the effect of various parameters such as the effect of adsorbent dosage, pH, time, concentration, and coexisting ions during arsenate ion (As(V)) adsorption. The kinetic and isotherm model indicates that the adsorption process follows the pseudo-second-order and Langmuir isotherm model, respectively, which reveals the chemisorption mechanism. From the Langmuir plot, the maximum adsorption capacity was found to be 36.1 mg/g, which is considerably greater than the earlier reported results. The stability and reusability of the membrane were demonstrated by five successive sorption–desorption cycles. After all, the As(V) loaded PAN/GO/γ-Fe2O3 nanofiber membrane was analyzed by FTIR, TEM-EDAX, and X-ray photoelectron spectroscopy (XPS) analytical technique to elucidate the possible adsorption mechanism, which suggests electrostatic attraction and surface complexation are the main driving forces for As(V) removal.