A comparative study for the removal of methylene blue dye by N and S modified TiO2 adsorbents

Successful removal of methylene blue (MB) dye from aqueous solutions using nitrogen and sulfur modified TiO2(P25) nanoparticles has been demonstrated in this study. The modified adsorbents were characterized using various analytical methods, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The adsorption potential of S-TiO2, N-TiO2 and TiO2(P25) type adsorbents was tested for the removal of MB dye. The kinetic studies indicated that the adsorption of MB dye followed the pseudo-first order model, while desorption processes followed the second order model. The adsorption capacity of the adsorbent proved to be increasing as a function of initial pH of the solution. The maximum adsorption capacities were found to be 350.66, 410.12 and 282.84 mg/g of S-TiO2, N-TiO2 and TiO2(P25), respectively. It can be concluded that modification of TiO2(P25) nanoparticles with N and S leads to a higher adsorptive removal of MB.