Direct synthesis of highly dispersible PACMA-capped TiO2 nanoparticles and its adsorption properties towards Pb(II)

Abstract

A simple low-temperature one-step synthetic method of a hybrid material involving TiO2 nanoparticles modified by an organic polymer is here reported. TiO2 nanoparticles were grown by hydrolysis of hexafluorotitanate using boric acid as a fluoride scavenger. TiO2 synthesis was performed in the presence of poly(acrylic acid-co-maleic acid) (PACMA). This procedure yields a crystalline TiO2 nanopowder capped with PACMA, termed PACMA@TiO2, according to X-ray diffraction and infrared spectroscopy characterization methods. Elemental analysis denotes the presence in the powder of a small amount of ammonium. Transmission and scanning electron microscopies show that the material is constituted by needles of ca. 200nm in length, fused into star-like particles. Selected area electron diffraction analysis indicates that the particles are aggregated and only partially organized. The dried powdered material can easily be dispersed in water. The colloidal suspension obtained is highly stable, and its potential application in heavy metal adsorption is demonstrated with aqueous Pb(II), followed by using inductively coupled plasma optical emission spectrometry.