Synthesis of cation-intercalated titanate nanobelts

Monovalent, bivalent and trivalent cations of Li+, Sn2+, Al3+, Fe3+ with different values of electronegativity were designed as doped-ions to prepare cations-intercalated titanate nanobelts through ex-situ ion-exchange reaction. XRD results revealed that the d200 values of layered TNBs decreased as the following sequence: Li-intercalated TNBs > Al-intercalated TNBs > Fe-intercalated TNBs > Sn-intercalated TNBs. The electronegativity differences between respective doped-cations and oxygen can well explain the trend of the reduction of d200 values for the synthesized layered nanobelts with different cations. The width change of nanobelts depending on intercalated cations showed similar tendency as that of d200 excluding Sn-intercalated case. That is mostly due to the crystallization of SnO2 nanoparticles on the nanobelts. Sn2+ is easily crystallized to form SnO2 nanoparticles on the surface of TNBs and being considered as unfavorable metal dopant for the present intercalation purpose. The reduction of d200 values of the doped TNBs from that of the undoped TNBs confirms the intercalation of the doped cations into layered structure. Such simple electronegativity-difference depending mechanism may be convenient for the designing of metal ion intercalation into octahedral TiO6 layered-oxide materials.