The preparation, surface structure, zeta potential, surface charge density and photocatalytic activity of TiO2 nanostructures of different shapes

• Published in: Applied surface science 2013-09, Vol.280, p.366-372
• Main Authors: Grover, Inderpreet Singh, Singh, Satnam, Pal, Bonamali
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Degradation of imidacloprid; Exact sciences and technology; Nanoscale TiO2 rods and tubes; Nanostructure; Photocatalysis; Physics; Sodium; Surface area; Surface charge; TiO2 photoactivity; TiO2 surface charge; Titanium dioxide; TNT; Zeta potential; Zeta potential of TiO2
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2013.04.163

•Superior photocatalytic activity of sodium titanate nanotube to P25-TiO2.•Electro-kinetic properties vary with synthesis condition of TiO2nanostructures.•Ag and Cu deposition did not significantly alter the electro-kinetic parameters.•Sodium content has no detrimental effect on the photoactivity of titanate nanotube. Titania based nanocatalysts such as sodium titanates of different morphology having superior surface properties are getting wide importance in photocatalysis research. Despite having sodium (Na) contents and its high temperature synthesis (that generally deteriorate the photoreactivity), these Na-titanates often exhibit better photoactivity than P25-TiO2 catalyst. Hence, this work demonstrated the influence of crystal structure, BET surface area, surface charge, zeta potential (ζ) and metal loading on the photocatalytic activity of as-prepared sodium titanate nanotube (TNT) and titania nanorod (TNR). Straw like hollow orthorhombic-TNT (Na2Ti2O5·H2O) particles (W=9–12nm and L=82–115nm) and rice like pure anatase-TNR particles (W=8–13nm and L=81–134nm) are obtained by the hydrothermal treatment of P25-TiO2 with NaOH, which in fact, altered the net surface charge of TNT and TNR particles. The observed ζ=−2.82 (P25-TiO2), −13.5 (TNT) and −22.5mV (TNR) are significantly altered by the Ag and Cu deposition. It has been found here that TNT displayed best photocatalytic activity for the imidacloprid insecticide (C9H10ClN5O2) degradation to CO2 formation under UV irradiation because of its largest surface area 176m2g−1 among the catalysts studied.