大量粘性纳米颗粒上的快速硅原子层沉积。

Rapid silica atomic layer deposition on large quantities of cohesive nanoparticles.

机构信息

Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, USA.

出版信息

ACS Appl Mater Interfaces. 2010 Aug;2(8):2248-53. doi: 10.1021/am100279v.

PMID:20735095

Abstract

Conformal silica films were deposited on anatase titania nanoparticles using rapid silica atomic layer deposition (ALD) in a fluidized bed reactor. Alternating doses of tris(tert-pentoxy)silanol (TPS) and trimethylaluminum (TMA) precursor vapors were used at 175 degrees C. In situ mass spectroscopy verified the growth mechanism through a siloxane polymerization process. Transmission electron microscopy revealed highly conformal and uniform silica nanofilms on the surface of titania nanoparticles. A growth rate of approximately 1.8 nm/cycle was achieved for an underdosed and incomplete polymerization reaction. Primary nanoparticles were coated despite their strong tendency to form dynamic agglomerates during fluidization. Methylene blue oxidation tests indicated that the photoactivity of anatase titania particles was mitigated with the ALD films.

摘要

采用快速硅原子层沉积（ALD）在流化床反应器中在锐钛矿型 TiO2 纳米粒子上沉积了共形二氧化硅薄膜。在 175°C 下交替使用三（叔戊氧基）硅醇（TPS）和三甲基铝（TMA）前体蒸气。原位质谱通过硅氧烷聚合过程验证了生长机制。透射电子显微镜显示，在 TiO2 纳米粒子的表面上形成了高度共形和均匀的二氧化硅纳米薄膜。在欠剂量和不完全聚合反应下，实现了约 1.8nm/循环的生长速率。尽管在流化过程中强烈倾向于形成动态团聚体，但仍对初级纳米粒子进行了包覆。亚甲基蓝氧化测试表明，ALD 薄膜减轻了锐钛矿 TiO2 颗粒的光催化活性。