Atomic layer deposition of titanium phosphate on silica nanoparticles

作者：Wiedmann Monika K^*; Jackson David H K; Pagan Torres Yomaira J; Cho Eunkyung; Dumesic James A; Kuech T F

来源：Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films , 2012, 30(1): 01A134.

DOI：10.1116/1.3664097

Titanium phosphate was deposited on silica nanoparticles by atomic layer deposition (ALD). The precursors were titanium tetrachloride (TiCl(4)), trimethylphosphate ((MeO)(3)PO), and water. Depositions were done at 150-300 degrees C employing a variety of pulse sequences which altered the self-limiting deposition process. Using the pulse sequence TiCl(4)-H(2)O-(MeO)(3)PO-H(2)O, the process was self-limiting at 200 degrees C, and <= 0.3 at.% Cl was incorporated into the material. With the pulse sequence TiCl(4)-H(2)O-(MeO)(3)PO, the process was not completely self-limiting at 200 degrees C and slightly more Cl incorporation occurred. Using the pulse sequence TiCl(4)-(MeO)(3)PO, the process was not self-limiting at 175 or 250 degrees C, and Cl incorporation was 0.2-2 at.%. The surface area of the material decreased from 300 m(2)/g for uncoated silica to 46 m(2)/g for silica coated with 60 ALD cycles.

• 出版日期2012-1