Hydrothermally Shape-Controlled Synthesis of TiO₂/Graphene for Fluoride Adsorption Studies

Although graphene has great potential in mitigating hazardous constituents that exist in wastewater, its stability, aggregation, and reusability are points of concern. To overcome this problem, we have prepared graphene incorporated with titanium oxide recyclable adsorbent by a hydrothermal strategy for the removal of fluoride from an aqueous system. The pristine graphene oxide with titanium oxide graphene (TiO₂–GO) nanocomposite was analyzed using several interpretative tools, namely, field emission scanning electron microscopy, Brunauer–Emmett–Teller, Fourier transform infrared, X-ray diffraction, and X-ray photoelectron spectroscopy. The TiO₂–GO nanocomposite exhibited good adsorption toward the toxic fluoride ion, with an adsorption capacity of 342 mg/g at pH 6.0 and a high surface area of 278 m²/g. Thermodynamic parameters ΔG°, ΔH°, and ΔS° revealed that adsorption is endothermic and spontaneous, and the equilibrium condition is favored by Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption isotherms. Adsorption–desorption up to the sixth cycle without the release of nanomaterial in solution confirms its reusability. Consequently, TiO₂–GO adsorbent is a promising adsorbent owing to its sustainability, reusability, and efficient adsorption, even in the presence of foreign ions in wastewater.