Facile fabrication of sodium carboxymethyl cellulose/reduced graphene oxide composite hydrogel and its application for Pb(II) removal

The sodium carboxymethyl cellulose/reduced graphene oxide (rGO-CMC) composite hydrogel was fabricated via environmental friendly one-step hydrothermal reduction method. The morphology, pore structure and surface properties of the as-prepared sample were characterized by scanning electron microscopy, Brunauer–Emmett–Teller surface area measurement and zeta potential analyser, respectively. To investigate the adsorption behaviour of rGO-CMC for Pb(II), effects of contact time, temperature, initial concentration and pH were studied in detail. The rGO-CMC composite before and after adsorption of Pb(II) was analysed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy to further explore adsorption mechanism. Compared with rGO, the adsorption capacities of rGO-CMC-3 composite for heavy metals including Pb(II), Cu(II), Ni(II), Mn(II), Co(II) were increased to 156.85, 35.70, 21.40, 20.85 and 15.80 mg g −1 , respectively. In addition, the rGO-CMC composite formed a complete aerogel after freeze-drying, which confirms its great potential as an easily separable adsorbent to remove heavy metals in aqueous solutions.