Department of Materials Science and Engineering, Northwestern University, 2220 North Campus Drive, Evanston, IL 60208-3108, United States of America. Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, United States of America.
Nanotechnology. 2017 May 5;28(18):185704. doi: 10.1088/1361-6528/aa688d.
Uniform, well-dispersed platinum nanoparticles were grown on SrTiO nanocuboids via atomic layer deposition (ALD) using (methylcyclopentadienyl)trimethylplatinum (MeCpPt(Me)) and water. For the first half-cycle of the deposition particles formed through two sequential processes: initial nucleation and growth. The final particle size after a single complete ALD cycle was dependent on the reaction temperature which alters the net Pt deposition per cycle. Additional cycles resulted in further growth of previously formed particles. However, the increase in size per cycle during additional ALD cycles, beyond the first, was significantly lower as less Pt was deposited due to carbonaceous material that partially covers the surface and prevents further MeCpPt(Me) adsorption and reaction. The increase in particle size was also temperature dependent due to changes in the net Pt deposition. Pt nanoparticles increased in size by 59% and 76% after 15 ALD cycles for reaction temperatures of 200 °C and 300 °C, respectively. There was minimal change in the number of particles per unit area as a function of reaction time, indicating that there was minimal Ostwald ripening or secondary nucleation for the reaction conditions.
通过原子层沉积（ALD），使用（甲基环戊二烯基）三甲基铂（MeCpPt（Me））和水，在 SrTiO3 纳米立方体上生长出均匀、分散良好的铂纳米颗粒。在沉积的前半周期，颗粒通过两个连续的过程形成：初始成核和生长。在单个完整的 ALD 循环后，最终的颗粒尺寸取决于改变每个循环净 Pt 沉积量的反应温度。额外的循环导致先前形成的颗粒进一步生长。然而，由于部分覆盖表面并阻止进一步 MeCpPt(Me) 吸附和反应的含碳物质，在第一个循环之后，每个额外 ALD 循环中增加的尺寸显著降低。由于净 Pt 沉积的变化，颗粒尺寸的增加也与温度有关。反应温度分别为 200°C 和 300°C 时，经过 15 个 ALD 循环，Pt 纳米颗粒的尺寸分别增加了 59%和 76%。随着反应时间的增加，单位面积上的颗粒数量变化很小，表明对于反应条件，奥斯特瓦尔德熟化或二次成核很小。
