Hydrothermal synthesis and intercalation behavior of a layered titanium phosphate Ti 2(H 2PO 4)(HPO 4)(PO 4) 2 · 0.5C 6N 2H 16, with an extended γ-phase intercalated into organic amine

Abstract

With a hydrothermal technique, a layered titanium phosphate with the formula Ti 2(H 2PO 4)(HPO 4)(PO 4) 2 · 0.5C 6N 2H 16 (denoted TP- J2) has been prepared by treating the Ti/H 3PO 4/H 2O/1-methylpiperazine system directly. The as-synthesized products were characterized by powder X-ray diffraction, CP-MAS solid-state 31P NMR spectroscopy, thermogravimetric and differential thermal analyses (TG-DTA). The structure was solved by single-crystal X-ray diffraction analysis and it presents an extended γ-phase intercalated with organic amine. Crystal data: triclinic, P 1 ¯ , a = 8.106 (2) Å, b = 8.197 (2) Å, c = 11.658 (2) Å. α = 78.32 (3)°, β = 80.85 (3)°, γ = 77.90 (3)°, Z = 2. Additionally, the intercalation behavior of TP- J2 with n-alkyl monoamine ( n = 2, 3, 4, 6, 8, 10 and 12) was investigated. Owing to the strong brønsted base, N, N′-dimethylpiperazine, resides in the interlayer, it presented unusual features of TP- J2 in contrast with that of γ-Tip.