Abstract:

K_0.81Li_0.27Ti_1.73O₄ was synthesized by a solid state reaction. The conditions such as materials ratios, reaction time and reaction temperature, which are the main influencing factors of the H+ ionic exchange reaction and exfoliation of  K_0.81Li_0.27Ti_1.73O₄ were studied. The results show that K_0.81Li_0.27Ti_1.73O₄ can be transformed into H_1.08Ti_1.73O₄·H₂O in a 0.1~14 mol/L HNO₃ solution by ionic exchange. If the reaction temperature is higher, the product is  transformed into TiO₂. The optimum H⁺exchange conditions are: the concentration of HNO₃ is 1~10 mol/L, n(HNO3) ∶〖KG-*3〗n(KLiTiO)=10~20, at room temperature for 4~7 d. H_1.08Ti_1.73O₄·H₂O can be exfoliated by both npropylamine (n\|PA) and nbutylamine. The exfoliation of H_1.08Ti_1.73O₄·H₂O  is sensibly influenced by the reaction temperature and the ratio of H_1.08Ti_1.73O₄·H₂O  and amine, i.e., at a higher temperature and/or a smaller ratio of amine and H_1.08Ti_1.73O₄·H₂O , the product is TiO₂ rather than a layered compound. The optimum exfoliation (or intercalation) conditions are: n(nPA) ∶ n(HTiO)=20~100, at 120 ℃ for 1 d.

Key words: layered oxides, layered titanate, H⁺ionic exchange, intercalation and exfoliation, K_0.81Li_0.27Ti_1.73O₄