Ultralight sulfonated graphene aerogel for efficient adsorption of uranium from aqueous solutions

An ultralight sulfonated graphene aerogel (GA-SO₃H) was synthesized via simply gas phase sulfonation and was adopted to adsorb U(VI) from radioactive wastewater. The characterization confirmed plentiful sulfonate groups on GA-SO₃H surfaces. GA-SO₃H exhibited high U(VI) sorption capacity with maximum amount of 148.4 mg g⁻¹ and reached maximum separation selectivity of 61.38% at 298 K and pH 5.0 due to the surface complexation between the O atoms of sulfonate groups and uranyl ions. Furthermore, GA-SO₃H exhibited satisfied regeneration and excellent structural stability. This paper highlighted ultralight GA-SO₃H as an efficient adsorbent for effective adsorption/recovery of uranyl ions from radioactive wastewater.