Synthesis and characterization of a novel layered titanium phosphate

Abstract

A novel metastable layered titanium phosphate has been synthesized by the treatment of layered titanates (Na2Ti3O7 and Na4Ti9O20) with 1–2 M phosphoric acid solution at 120–150 °C. Based on the data of 31P MAS NMR and IR spectroscopy, x-ray powder diffraction, and thermal and elemental analysis, the formula Ti2O3(H2PO4)2 · 2H2O was assigned to the novel compound. The layered nature of the compound was confirmed from n-alkylamine intercalation and the ion exchange behavior toward alkali, alkaline earth, and some transition metal ions.

Sorption performances of TiO(OH)(H2PO4)·H2O in synthetic and mine waters

“…It has been reported that loading ion-exchangers with alkaline ions improved considerably their sorption characteristics and that the amount of exchangeable Na + represented the actual IEC of the sorbents. 15,16,30 In this work, the sodium form of TiP1 was obtained by treating H-TiP1 with 0.5 M Na 2 CO 3 for 24 h, under stirring, at ambient conditions. Fig.…”

“…3) reported for TiP-IE in various studies. 4,15,16,30,37,38 It has been shown that the conversion of aTiP into its alkaline form could result in a Na + uptake from 2. Likewise, the formation of three phases in the case of TiP1 is most likely to happen: TiO(OH)(H 2 PO 4 ), TiO(OH)(HNaPO 4 ) and TiO(OH)(Na 2 PO 4 ) and the latter one would start forming aer pH > 6.…”

“…30,41 To investigate adsorption processes in detail, pH controlled experiments and low concentrations of metal ions shall be applied. In this work, to determine the sorption capacity of Na- Fig.…”

“…It has been shown that the modication of titanium phosphate ion-exchangers into an alkaline form increased their sorption capacity. 15,16,30 Therefore, TiP1 in H + -form (H-TiP1, i.e.…”

Syntheses and Structures of Two Reduced Open-framework Titanophosphates

“…19 Two layerd structures and an anhydrous form of γ-Ti(H 2 PO 4 )(PO 4 )·H 2 O were reported in the early 1990s. [20][21][22] Clearfield and co-workers contributed three porous structures, which contain monomeric, dimeric and trimeric TiO 6 octahedra respectively. 23 Several new titanophosphate and titanophosphonate compounds were isolated by Ferey's group and Pang's group in the past few years.…”