Potassium polytitanates intercalated with nickel ions and their thermal transformations

The intercalation of nickel ions into the layered structure of ultradispersed amorphous potassium polytitanate powder on treatment with an aqueous solution of nickel sulfate was studied. The limiting nickel content that can be attained by intercalation is 12.8 wt %. The nickel ion intercalation results in a decrease in the average particle size of potassium polytitanate and in the structural ordering. Heat treatment of the resulting intercalate promotes the formation of a nanocomposite consisting of the solid solution K_1.35(Ni _x Ti_{8 − x} )O₁₆ with the hollandite structure, Ti₂O₃, and, depending on the treatment schedule, either NiO nanocrystals or Ni metal.