Hierarchical porous biochar-based functional materials derived from biowaste for Pb(II) removal

Here we presented a functional biochar materials (FBM) with hierarchical porosity derived from bio-waste (soybean cake) by one-step carbonization method at different temperatures (500–800 °C). Various functional groups generated from the carbonized soybean cakes are rich in heteroatom elements (O, N, and P) of endosperm and silanol groups of epiderm. The optimized proportion of functional/silanol hybridized groups was observed in FBM-700 (at 700 °C) with hierarchical structure, which exhibits highest Pb(II) absorption capacity of 133.6 mg g−1 at pH = 5. Various functional groups of FBM-700 with hierarchical structure provide efficient active sites and easy-transport ion channels, leading to synergistic effects for high removal capacity of heavy metals ions. This work provides a green, environment-friendly and scale-up method to fabricate biochar-based functional materials from biowaste for the treatment of heavy metal pollution.