Heavy metal ions pose a significant environmental threat due to their non-degradability and accumulation to toxic levels. In addressing this challenge, we have designed two novel hydrogels through radical polymerization, an efficient and cost-effective method, using sulfonate groups. One hydrogel remained pristine, while the other was hybridized with few-layer graphene (FLG). The incorporation of FLG interacts with the polymeric network without compromising its thermal stability, as confirmed by Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). It also reduces pore size (from 42 to 35 µm), enhances mechanical properties (Young's modulus increased from 32 to 44 kPa), and increases the swelling degree (from 62 to 76), while maintaining a high adsorption capacity. The ability of both hydrogels to adsorb Pb²⁺, Ni²⁺, and Cd²⁺ ions from aqueous solutions was examined. These hydrogels demonstrated high adsorption capacity (q