Simple and effective one-step production of high-quality mesoporous pyrolytic char from waste tires: Rhodamine B adsorption kinetics and density functional theory (DFT) study

Abstract

Pyrolytic tire (PT) chars were first produced from waste car tires (WCT) through carbonization process at 800 degrees C, for different retention times. Then, best PT-char sample by its physicochemical properties (WCT 800(1 h)) was further tested for its ability to adsorb Rhodamine B (RhB) dye from aqueous solutions. Structural characterization of synthesized material showed existence of graphene-based material, with average pore diameter of 22.8 nm and specific surface area of 55.8 m2.g- 1. Obtained carbon material meets specifications of commercial carbon black (CB). The yield of 33.6% of CB recovered has been achieved. Under the optimal conditions, 99.57% of RhB was removed. Adsorption of RhB obeys pseudo second-order model and Langmuir isotherm model. DFT (the density functional theory) was revealed that effective bonding of RhB onto WCT 800 originates from pi-electron interactions with aromatic moieties and chemical (or at least the electrostatic) interactions, between positive nitrogen and electron-rich surface groups.