Growth of ZrO2 films on mesoporous silica sieve via atomic layer deposition

Author(s)

Rasteiro, Leticia F. ; Motin, Abdul ; Vieira, Luiz H. ; Assaf, Elisabete M. ; Zaera, Francisco

• Document type: Journal article
• Source: Thin Solid Films; v. 768, p. 6-pg., 2023-02-01.

Abstract

The atomic layer deposition of ZrO2 thin films over the mesopores of a mesoporous silica sieve, SBA-15 (Santa Barbara Amorphous-15), using the tetrakis(dimethylamino)zirconium(IV) (TDMAZ) as ZrO2 precursor was tested and characterized using N2 adsorption-desorption isotherms, taking advantage of the well-defined shape and size distribution of the pores in the SBA-15. Three samples were prepared, using 2, 4, and 6 deposition cycles to control the thickness of the films. It was determined that, as the average size of the pores decreased (with the increasing number of cycles), their size distribution remained narrow, indicating a homogeneous distribution of the ZrO2 throughout the surfaces of the SBA-15 pores. This conclusion was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy. The deposition rate appears to slow down after 4 cycles, an observation that we explain by different chemisorption properties of TDMAZ molecules over SBA-15 and ZrO2 surface and by relating the kinetic diameter of TDMAZ with the pore diameter of SBA-15 after 4 deposition cycles: mass transport limitations have become significant at this point. They may be affected by complex factors like electronic effects caused by exposed ZrO2 surface and the multi-directional adsorption of precursor mole-cules in the pore walls. (AU)

• FAPESP's process: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Grantee: Julio Romano Meneghini
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 17/22671-5 - Ga-Ni nanoparticles supported on porous silica for methanol synthesis from CO2 at low pressures
• Grantee: Letícia Fernanda Rasteiro
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/22260-0 - Sub-monolayer control of the growth of ZrO2 films over ordered mesoporous silica supports and interface tailoring of Ni-Ga catalysts by atomic layer deposition (ALD)
• Grantee: Letícia Fernanda Rasteiro
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 18/12021-6 - Partial oxidation of methane to methanol catalyzed by single-atom noble metal (Rh, Pd or Pt) supported on doped mesoporous CeO2 (Ce1-xMxO2, M = Zr, Sn or La)
• Grantee: Luiz Henrique Vieira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants