Adsorption and Removal Characterization of Nitrobenzene by Graphene Oxide Coated by Polythiophene Nanoparticles

Nitrobenzene (NB) has a wide range of usages as a chemical intermediate and also as a dye in printing applications. Despite its advantages, NB is harmful to human and animals and hence is an environmental pollutant. In this research, NB removal from water was studied via adsorption on graphene oxide (GO) coated by polythiophene (PT) nanoparticles. The resulting nanocomposite was characterized by XRD, FTIR, BET, and SEM. While the FTIR tests proved successful incorporation of PT, the SEM images displayed a relatively larger surface area compared to other studies. The BET analysis confirms this finding by reporting the surface area as 917.8 m2/g for the adsorbent. The adsorption mechanism was assessed by the Langmuir and Freundlich isotherms. The results show that the Freundlich isotherm better describes the adsorption process compared to the Langmuir isotherm. On the other hand, the pseudo-second-order kinetic model better regresses the experimental results, which indicates a chemical adsorption mechanism. The adsorption-desorption behavior of the samples was evaluated at optimized pH, time, adsorbent dosage, and eluent type. The results showed that the synthesized nanocomposite can efficiently remove NB from solutions in the pH range of 5.0 to 7.0, with the maximum adsorption capacity of 15.6 mg/g.