Versatile, flexible rice starch–graphene oxide bio-nanocomposites†

In light of the pressing challenge of global plastic and water pollution, this study seeks a single solution by exploring the remarkable potential of rice starch (RS)–graphene oxide (GO) bio-nanocomposite films. RS–GO composite films were prepared with varying GO concentrations. As the GO weight percentage was increased from 0 wt% to 1 wt% of starch, the ultimate tensile strength of the composite was seen to increase by 438%, whereas a marginal decrease of 29% in elongation was observed. Reinforcement of GO into the starch film also helped to enhance the melting temperature because of the strong hydrogen bond formation between RS and GO sheets. Apart from the enhanced mechanical and thermal stability of the prepared composite films, they also exhibited antibacterial properties against both Gram-positive and Gram-negative bacterial strains, encouraging their use in food packaging and storage industries. In addition, the use of RS–GO biocomposites as adsorbent materials for lead removal from wastewater was also explored. As the GO concentration was increased in the composite film, the Pb(II) ion removal efficiency (RE) also increased, with a maximum RE of 99% observed for 5 wt% GO film from 10 ppm Pb(II) water solution. In conclusion, the ability of RS–GO bio-nanocomposites to address plastic and water pollution adds to their value as eco-friendly materials.