Enhanced adsorption of Ag+ on triethanolamine modified titanate nanotubes

A novel high adsorption capacity adsorbent of triethanolamine modified titanate nanotubes (TEOA-TNTs) was prepared by simple hydrothermal process and modification technique. The FT-IR, XPS, Zeta-potential and nitrogen adsorption-desorption results showed that titanate nanotubes (TNTs) was successfully modified by triethanolamine (TEOA) via electrostatic interaction and laTEOA) via electrostatic interaction and lattice doping. The as-prepared TEOA-TNTs exhibited a significant enhancement on adsorption capacity towards Ag+ compared with TNTs. The adsorption isotherm of Ag+ on TEOA-TNTs fitted the Langmuir equation well and the maximum adsorption capacity of TEOA-TNTs for Ag+ was estimated to be 396 mg/g at 25 °C. The chelation and reduction mechanism of Ag+ on TEOA-TNTs was confirmed by the pseudo second-order adsorption kinetics assessments and the existence of metallic silver on TEOA-TNTs. Considering its relative simple preparation procedure, TEOA-TNTs can be a promising candidate for the recovery of Ag+ from the aqueous solution.

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