Glass beads immobilized doped TiO2 NPs with enhanced adsorption efficiency for arsenic(III) from aqueous solution

Abstract

Visible light driven metals (Gd and Tl) doped TiO2 nanoparticles (NPs) were prepared using low cost and facile liquid impregnation method. The prepared NPs were characterized using XRD, SEM/EDX, BET surface area analysis, particle size distribution analyzer, UV–Vis DRS and pH of point of zero charge (pHPZC) analyses. The crystalline phases observed were purely anatase with the particles size ranged between 24 and 30 nm possessing large surface area (74 m2/g) and pore size (12 nm). The reductions in the band gap energy for both the dopant systems were observed and absorption edges were extended to the visible region. The prepared NPs exhibited good photo-induced adsorption affinity for the As(III) from aqueous solution under natural pH of As(III) solution, ambient temperature and normal household compact fluorescent light. The metals-doped NPs showed high removal efficiency (up to 99%) towards As(III) compared to pure TiO2 NPs (68%). In addition, the glass beads immobilized photocatalyst not only enhanced the efficiencies by increasing the active surface area of NPs, but also overcome the post-reaction separation steps. The regeneration study indicated that the physical regeneration is more significant for the reutilization of photocatalysts.