Hashemi Fatemeh S M, Grillo Fabio, Ravikumar Vikram R, Benz Dominik, Shekhar Ankit, Griffiths Matthew B E, Barry Seán T, van Ommen J Ruud
Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, The Netherlands.
Nanoscale. 2020 Apr 30;12(16):9005-9013. doi: 10.1039/d0nr01092h.
Gold nanoparticles have been extensively studied for their applications in catalysis. For Au nanoparticles to be catalytically active, controlling the particle size is crucial. Here we present a low temperature (105 °C) thermal atomic layer deposition approach for depositing gold nanoparticles on TiO2 with controlled size and loading using trimethylphosphino-trimethylgold(iii) and two co-reactants (ozone and water) in a fluidized bed reactor. We show that the exposure time of the precursors is a variable that can be used to decouple the Au particle size from the loading. Longer exposures of ozone narrow the particle size distribution, while longer exposures of water broaden it. By studying the photocatalytic activity of Au/TiO2 nanocomposites, we show how the ability to control particle size and loading independently can be used not only to enhance performance but also to investigate structure-property relationships. This study provides insights into the mechanism underlying the formation and evolution of Au nanoparticles prepared for the first time via vapor phase atomic layer deposition. Employing a vapor deposition technique for the synthesis of Au/TiO2 nanocomposites eliminates the shortcomings of conventional liquid-based processes opening up the possibility of highly controlled synthesis of materials at large scale.
金纳米颗粒因其在催化领域的应用而受到广泛研究。要使金纳米颗粒具有催化活性，控制颗粒大小至关重要。在此，我们介绍一种低温（105°C）热原子层沉积方法，该方法使用三甲基膦基 - 三甲基金（III）以及两种共反应物（臭氧和水），在流化床反应器中在二氧化钛上沉积具有可控尺寸和负载量的金纳米颗粒。我们表明前驱体的暴露时间是一个可变因素，可用于将金颗粒尺寸与负载量解耦。臭氧暴露时间延长会使颗粒尺寸分布变窄，而水暴露时间延长则会使其变宽。通过研究金/二氧化钛纳米复合材料的光催化活性，我们展示了独立控制颗粒尺寸和负载量的能力不仅可用于提高性能，还可用于研究结构 - 性能关系。本研究深入探讨了首次通过气相原子层沉积制备的金纳米颗粒形成和演化的潜在机制。采用气相沉积技术合成金/二氧化钛纳米复合材料消除了传统液相法的缺点，为大规模高度可控地合成材料开辟了可能性。
