Investigation of the Hydrophobic Nature of Metal Oxide Surfaces Created by Atomic Layer Deposition
Investigation of the Hydrophobic Nature of Metal Oxide Surfaces Created by Atomic Layer Deposition
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DOI：
10.1021/acs.langmuir.9b00577
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发表时间：
2019-04-30
期刊：
影响因子：
3.9
通讯作者：
Snurr, Randall Q.
中科院分区：
文献类型：
--
作者：
Bae, Jongyoon;Samek, Izabela A.;Snurr, Randall Q.
在催化剂材料的设计中可以利用表面疏水性来提高它们的活性和选择性。一种用于改变活性位点周围环境的疏水性的通用方法是原子层沉积（ALD）。在这项工作中，Al 2 O3，TiO 2，和SiO2沉积ALD以及CeO 2沉积的电子束蒸发-所有的α-Al 2 O3晶片上进行了研究，以确定其固有的疏水性和暴露于大气中后的任何变化。将金属氧化物薄膜的性质与单晶α-Al 2 O 3、α-SiO 2和Y/ZrO 2的性质进行比较。与水的接触角测量结合X-射线光电子能谱研究被应用于确定金属氧化物的疏水性和元素含量。单晶和薄膜的金属氧化物被发现是本质上亲水性的快速热处理程序后。在暴露于空气中时，所研究的金属氧化物表面变得越来越疏水，与碳质物质的吸附相关。通过ALD沉积的金属氧化物薄膜表现出与其单晶等效物相同的疏水性行为。
Surface hydrophobicity can be exploited in the design of catalyst materials to improve their activity and selectivity. One versatile method for modifying the hydrophobicity of the environment surrounding an active site is atomic layer deposition (ALD). In this work, Al2O3, TiO2, and SiO2 deposited by ALD as well as CeO2 deposited by electron beam evaporation-all on alpha-Al2O3 wafers-are investigated to determine their intrinsic hydrophobicity and any changes upon exposure to the atmosphere. The properties of metal oxide thin films are compared to those of single-crystal alpha-Al2O3, alpha-SiO2, and Y/ZrO2. Contact angle measurements with water combined with X-ray photoelectron spectroscopy studies are applied to determine the hydrophobicity and elemental content of the metal oxides. Both the single-crystal and thin-film metal oxides are found to be intrinsically hydrophilic following a rapid thermal-processing procedure. Upon exposure to air, the investigated metal oxide surfaces become increasingly hydrophobic, correlated to the adsorption of carbonaceous species. Metal oxide thin films deposited by ALD exhibit the same hydrophobicity behavior as their single-crystal equivalents.