Adsorption and photocatalytic degradation of 2,4-dicholrophenol using surgical mask derived SMAC-Fe₂O₃ composite; adsorption isotherms, kinetics, thermodynamics

Hybrid material of surgical mask activated carbon (SMAC) and Fe₂O₃ (SMAC-Fe₂O₃) composite was prepared by simple co-precipitation method and used as potential material for the remediation of 2,4-dicholrophenol (2,4-DCP). The XRD patterns exhibited the presence of SMAC and Fe₂O₃, FTIR spectrum showed the FeO-carbon stretching at the wavenumber from 400 to 550 cm⁻¹. UV–Vis DRS results showed the band gap was 1.97 eV and 2.05 eV for SMAC-Fe₂O₃ and Fe₂O₃, respectively. The SEM images revealed that the Fe₂O₃ doped onto the fiber morphology of SMAC. The outcomes of the BET examination exhibited a surface area of 195 m²/g and a pore volume of 0.2062 cm³/g for the SMAC/Fe₂O₃ composite. The batch mode study shows the maximum adsorption and photocatalytic degradation efficacies which were 97% and 78%, respectively. The experimental data was studied with both linear and nonlinear adsorption isotherm and kinetics models. The nonlinear Langmuir isotherm and pseudo-second-order kinetics (PSOK) models have well fit compared with other models. The Langmuir maximum adsorption capacity (q_max) was found 161.60 mg/g. Thermodynamic analysis shows that the 2,4-DCP adsorption onto SMAC-Fe₂O₃ was a spontaneous and exothermic process. The PSOK assumes that the adsorption process was chemisorption. The photocatalytic degradation rate constant of 2,4-DCP was calculated using pseudo-first-order kinetics (PFOK) and the rate constant for SMAC-Fe₂O₃ and Fe₂O₃ were 0.859 × 10⁻² min⁻¹ and 0.616 × 10⁻² min⁻¹, correspondingly. In addition, the obtained composite exhibited good reusability after a few cycles. These results confirmed that SMAC-Fe₂O₃ composite is an effective adsorbent and photocatalyst for removing 2,4-DCP pollutants.