Radiation synthesis of graphene oxide/composite hydrogels and their ability for potential dye adsorption from wastewater

A high yield of graphene oxide (GO) was chemically synthesized from graphite powder utilizing adjusted Hummer's method. The contents of acidic functional groups in GO were determined using potentiometric titration. Composite hydrogels dependent on graphene oxide/poly(2-acrylamido-2-methylpropan esulfonic acid)/polyvinyl alcohol (GO/PAMPS/PVA) were synthesized utilizing a Co-60 gamma irradiation source at different doses. The synthesized graphene oxide and composite hydrogels were portrayed via X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared analysis. The morphology of composite hydrogels was characterized by scanning electron microscope. The gel % and swelling % for the prepared hydrogel demonstrated that the swelling % of hydrogel increased with raising AMPS content. Whereas the increment of GO and increasing the irradiation dose lead to a reduction in the swelling %. The influences of pH, GO percentage, initial dye concentration, the adsorbent dosage, contact time, and temperature on the adsorption of basic blue 3 dye were evaluated and the adsorption capacity was 194.6 mg/g at optimum conditions; pH = 6, GO/PAMPS/PVA composite hydrogels with 5 wt% of GO, initial dye concentration = 200 mg/L, adsorbent dose = 0.1 g, solution volume = 50 mL after 360 min at room temperature (25 degrees C). The adsorption of dye onto the GO/PAMPS/PVA composite hydrogels follows Pseudo-second-order adsorption kinetics, fits the Freundlich adsorption isotherm model.

Automated summary

A high yield of graphene oxide was chemically synthesized from graphite powder using adjusted Hummer's method, and the acidic functional groups in GO were determined using potentiometric titration. Composite hydrogels based on GO/PAMPS/PVA were synthesized with different doses of Co-60 gamma irradiation source. The adsorption of basic blue 3 dye onto the GO/PAMPS/PVA composite hydrogels followed Pseudo-second-order kinetics and fit the Freundlich adsorption isotherm model, with an optimum adsorption capacity of 194.6 mg/g under specific conditions.