@article{Gosavi2019, 
author = {Abha A. Gosavi and James L. Hedrick and Peng-Cheng Chen and Justin M. Notestein and Chad A. Mirkin},
title = {A tri-layer approach to controlling nanopore formation in oxide supports},
year = {2019},
journal = {Nano Research},
volume = {12},
number = {6},
pages = {1223-1228},
keywords = {atomic force microscopy, Au nanoparticles, nanopore formation, nanoparticle entrenchment, nanoparticle stabilization},
url = {https://www.sciopen.com/article/10.1007/s12274-019-2332-9},
doi = {10.1007/s12274-019-2332-9},
abstract = {A novel tri-layer approach for immobilizing metal nanoparticles in SiO2 supports is presented. In this work, we show that under rapid heating to temperatures of approximately 1, 000 ℃, metal nanoparticles less than 15 nm in size will entrench in the SiO2 layer on a silicon wafer to create pores as deep as 250 nm. We studied and characterized this entrenching behavior and subsequent nanopore formation for a wide variety of metal nanoparticles, including Au, Ag, Pt, Pd, and Cu. We also demonstrate that an Al2O3 layer acts as a barrier to such pore formation. Thus, by creating a tri-layer architecture consisting of SiO2 on Al2O3 on silicon wafers, we can control the depth to which nanoparticles entrench between 3-5 nm. This small range allows one to entrench particles for the purpose of immobilization but still present them above the surface. The two advances of moving into the sub-15 nm size regime and of controlled particle immobilization through entrenchment have important implications in studying site-isolated and stabilized metal nanoparticles for applications in sensing, separations, and catalysis.}
}