Comparative Efficiency of ZIF‐67 and ZIF‐67@ZnO Nanocomposites for Trypan Blue Adsorption: Preparation and RSM Modeling

Abstract

ABSTRACT Efficient removal of Trypan Blue (TrB) from wastewater was achieved using ZIF67 and ZIF‐67@ZnO composite (NCs) synthesized via a solvothermal method. The obtained porous materials were characterized using different techniques such as x‐ray diffraction (XRD), Fourier transform infrared (FT‐IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The XRD data indicated the high crystalline nature of the obtained materials, and the SEM image showed a homogeneous morphology and highly porous structure. The effect of several parameters, such as different doses, initial concentration of dye, contact time, and pH conditions, on the removal rate of TrB dye was investigated. The maximum removal rate of TrB dye was 90%, 96% for ZIF‐67 and NCs, respectively, at pH = 5 and T = 25°C. The obtained findings indicated that the Langmuir model was more convenient, with an adsorption capacity ( Qe ) of 50 mg/g, for NCs, and the Kinetic data were best described by a pseudo‐second‐order model. Indeed, the thermodynamic properties exhibited an endothermic and spontaneous adsorption process. The response surface methodology (RSM) was used by the Box–Behnken design (BBD) model to examine the effects of the parameters such as pH, adsorbent dosage, initial dye concentration, and contact time on TrB removal. The optimum conditions for the removal of 99.91% were pH 3.25, absorbent dose 0.067 g/L, initial concentration 118.9 ppm, and contact time 33.04 min. Therefore, our findings revealed that NCs could be used as an efficient material for dye removal from wastewater.