Co3O4 co-doped TiO2 nanoparticles as a selective marker of lead in aqueous solution

Co3O4 co-doped TiO2 nanoparticles were prepared by a low temperature thermal method and their functional relationships with metal ions was investigated using solid phase extraction. The analytical potential of Co3O4 co-doped TiO2 nanoparticles was studied for the selective extraction of lead using inductively coupled plasma-optical emission spectrometry. The selectivity of Co3O4 co-doped TiO2 nanoparticles was investigated toward different metal ions, including Cd(II), Co(II), Cr(III), Cu(II), Fe(II and III), Hg(II), La(III), Mn(II), Ni(II), Pb(II), Pd(II) and Y(III). Data obtained from the selectivity study showed that Co3O4 co-doped TiO2 nanoparticles have the highest selectivity toward Pb(II). The uptake capacity for Pb(II) was experimentally calculated to be 114.05 mg g−1. Moreover, adsorption isotherm data of Pb(II) on Co3O4 co-doped TiO2 nanoparticles fit well with the Langmuir adsorption isotherm, strongly supporting that the adsorption process was mainly as a monolayer on Co3O4 co-doped TiO2 nanoparticle surfaces.