Poly (4,4'-methylenedianiline)-graphene oxide nanocomposite: synthesize and application in removal of benzothiophene from model liquid fuel

The adsorption of sulfur-containing compounds from fuels on polymer nanocomposite adsorbents modified with carbon-based materials was investigated. This work reports the removal of benzothiophene from the model liquid fuel using a novel adsorbent prepared by nanopoly (4,4'-methylenedianiline)-graphene oxide (NPMDA/GO) composite. The adsorbent was successfully synthesized with the in situ electrochemical method and characterized using thermal gravimetric analysis (TGA), field-scattering scanning electron microscopy (FE-SEM), transient electron microscopy (TEM), X-ray diffraction analysis (XRD), and Fourier transform infrared (FTIR). The results showed that the presence of graphene oxide (GO) nanosheets in NPMDA/GO composite adsorbent due to its high tendency to sulfur would increase the adsorption of benzothiophene compared to unmodified nanopoly (4,4'-methylenedianiline) (NPMDA). The π_complexation, oxygenated organic functional groups, and layered sheets of graphene oxide improve adsorption capacity for desulfurization. The NPMDA/GO composite presented maximum efficiency (63.33%) at 30 mg/L initial concentration, 120 mg adsorbent dose, and 120 min contact time at 25 °C. Furthermore, the adsorbent shows an almost good reusability after four cycles (67.12 mg/g sulfur absorption capacity). Pseudo-second-order model (R² = 0.9975) and the Freundlich isotherm (R² = 0.8813) were used to describe the adsorption process. Findings confirm that NPMDA/GO composite can be applicable for removal of benzothiophene from liquid fuels.