Eco-friendly Al-Bi2WO6 nanosheets for effective elimination of crystal violet and methylene blue dyes

A hydrothermal technique was followed to prepare an aluminum doped bismuth tungstate (Al-Bi ₂ WO ₆ ) nanostructure. X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX), Raman scattering spectroscopy (RS), Fourier transform infrared spectroscopy (FTIR), High resolution-transmission electron microscopy (HR-TEM), and Brunauer-Emmett-Teller (BET) method were employed to characterize the synthesized sheet-like nanostructure. The XRD admitted the existence of an orthorhombic structure of synthesized samples. Al-Bi ₂ WO ₆ nanostructure was used as an adsorbent to eliminate crystal violet (CV) and methylene blue (MB) dyes from the aqueous solution. A series of batch experiments were conducted to investigate the removal efficiency of the synthesized nanostructure for CV and MB dyes, varying parameters such as pH, adsorbent dose, contact time, initial concentration, and temperature. The outcomes demonstrate that the most prominent removal percentage of CV and MB dyes at 20 mg/L is 96% and 98%, at 20 and 25 minutes, respectively. The saturated adsorption capacity of Al-Bi ₂ WO ₆ to CV and MB dyes achieved 30.57 mg/L and 15.11 mg/g, from 20 to 50 mg/L, respectively. Moreover, adsorption kinetics and isotherms were best matched with the Langmuir and Pseudo-second-order models, respectively. Further, the thermodynamics factors confirmed that the adsorption process is an exothermic process.