Separation of 1‐Naphthol from Wastewater Using HF‐Free Microwave‐Assisted Synthesized MIL‐101(Cr): Kinetics, Thermodynamics and Reusability Studies**

Abstract Microwave‐assisted synthesis of Chromium (III) Terephthalate Metal Organic Framework, MIL‐101(Cr), was achieved in an aqueous media in the absence of hydrofluoric acid (HF). The synthesized material was characterized using Fourier transform infrared spectroscopy, powder X‐ray diffraction, nitrogen adsorption/desorption isotherms and field emission scanning electron microscope. Results indicate that the synthesized MIL‐101(Cr) using microwave irradiation poses higher surface area than those obtained using autoclave in a conventional oven method. Adsorptive removal of 1‐naphthol from aqueous solution using synthesized MIL‐101(Cr) was evaluated at various temperatures and concentrations. The Langmuir and Freundlich isotherms are used to describe the adsorption equilibrium behavior. The pseudo–second order and intraparticle kinetic models were applied to understand the rate limiting step and the mechanism of 1‐naphthol adsorption. The thermodynamic analysis of solid‐liquid system was investigated. The synthesized MIL‐101(Cr) showed higher 1‐naphthol adsorption capacity, compared to other adsorbents like biochar and multiwall carbon nanotube.