Highly Efficient Indium(III) Collection from Water by a Reaction with a Layered Titanate (Na 2 Ti 3 O 7 )

The reaction of an aqueous solution of indium(III) chloride with a sodium titanate (Na 2 Ti 3 O 7 ) is investigated. The remaining amount of the indium(III) in the aqueous solution after the reaction with Na 2 Ti 3 O 7 has been examined to show the efficient collection of indium(III) from the aqueous solution. The maximum collected indium(III) amount for Na 2 Ti 3 O 7 is 2 mmol/g Na 2 Ti 3 O 7 , which is superior to other reported ion exchangers. The collected indium(III) exists as indium hydroxide particles, with a particle size of several tens of nm (the size of microns), on the surface of H 2 Ti 3 O 7 , which formed from Na 2 Ti 3 O 7 through proton–sodium exchange during the reaction.