Design and characterization of a biomass template/SnO2 nanocomposite for enhanced adsorption of 2,4-dichlorophenol

2,4-Dichlorophenol (2,4-DCP) is a hazardous chlorinated organic chemical derived from phenol that exerts serious effects on living organisms. In the present study, SnO 2 templated with grapefruit peel carbon as a nanocomposite (SnO 2 @GPC) was designed via ball-milling, and its mechanism of 2,4-DCP adsorption in aqueous solution was determined. Batch adsorption experiments revealed that the maximum adsorption efficiency of SnO 2 @GPC occurred at 6.0 pH, 3 mg L −1 initial adsorbate concentration, 2 h contact time, and 293 K temperature. The SnO 2 @GPC nanocomposite and its non-tin-bearing counterpart, grapefruit derived char (@GPC), showed maximum adsorption capacities (Q L ) of 45.95 and 22.09 mg g −1 and partition coefficients of 41.77 and 10.83 mg g −1 μM −1 , respectively. The adsorption of 2,4-DCP was best described by the Redlich−Peterson model followed by the Langmuir model with high correlation coefficients (R 2  ≥ 0.96), and the adsorption kinetic data best fitted the pseudo-second-order model (R 2  ≥ 0.98). The thermodynamic parameters indicated that the reaction was spontaneous, exothermic, and involved high affinity between SnO 2 @GPC and 2,4-DCP. The high desorption efficiency obtained (>80%) demonstrated the recyclability of the adsorbent. The enhanced Q L of SnO 2 @GPC was due to the effective combination of GPC and SnO 2 . A thin porous layer of GPC on SnO 2 nanoparticles provided effective channels, a large surface area, and an abundance of active sites for 2,4-DCP adsorption. Thus, the SnO 2 @GPC nanocomposite could potentially be used as a low-cost adsorbent to remove 2,4-DCP from water.