Yahagi Tomohiro, Togashi Takanari, Kurihara Masato
Faculty of Science, Yamagata University 1-4-12 Kojirakawa-machi Yamagata 990-8560 Japan
Technical Support Center, National Institute of Technology, Tsuruoka College 104 Sawada, Inooka Tsuruoka Yamagata 997-8511 Japan.
RSC Adv. 2020 Jan 28;10(8):4545-4553. doi: 10.1039/c9ra10307d. eCollection 2020 Jan 24.
An exclusive deposition method of Ag nanoparticles (NPs) on TiO particles has been developed. Ag NPs supported on TiO particles, Ag /TiO, with various Ag weight ratios total weights of Ag and TiO between = 2 and 16 wt% are prepared low-temperature thermal decomposition of Ag(i)-alkyldiamine complexes generated by a reaction between AgNO and ,-dimethyl-1,3-propanediamine (dmpda) in an aqueous medium suspending TiO particles. The thermal decomposition of the Ag(i)-alkyldiamine complexes is accelerated by TiO particles in the dark, indicating that the reaction catalytically occurs on the TiO surfaces. Under optimised reaction conditions, the thermal decomposition of the complex precursors is completed within 3 hours at 70 °C, and Ag NPs are almost exclusively deposited on TiO particles with high conversion efficiencies (≥95%) of the precursor complexes. The thermal decomposition rates of the precursor complexes are strongly influenced by the chemical structure of a family of water-soluble dmpda analogues, and dmpda with both primary and tertiary amino groups is adopted as a suitable candidate for the exclusive deposition method. The number-averaged particle sizes of the Ag NPs are 6.4, 8.4, 11.8 and 15.2 nm in the cases of Ag /TiO, = 2, 4, 8 and 16, respectively. To the best of our knowledge, the as-prepared Ag /TiO samples show one of the highest catalytic abilities for the hydrogenation reduction of 4-nitrophenol into 4-aminophenol as a model reaction catalysed by Ag NPs.
已开发出一种在TiO颗粒上独家沉积银纳米颗粒（NPs）的方法。通过在悬浮TiO颗粒的水介质中，使AgNO₃与N,N-二甲基-1,3-丙二胺（dmpda）反应生成的Ag(i)-烷基二胺配合物进行低温热分解，制备了具有不同Ag重量比（Ag和TiO的总重量在2至16 wt%之间）的负载在TiO颗粒上的Ag NPs，即Ag/TiO。在黑暗中，TiO颗粒加速了Ag(i)-烷基二胺配合物的热分解，这表明该反应在TiO表面催化发生。在优化的反应条件下，配合物前体在70°C下3小时内完成热分解，并且Ag NPs几乎完全以高转化效率（≥95%）沉积在TiO颗粒上。前体配合物的热分解速率受一系列水溶性dmpda类似物的化学结构强烈影响，具有伯氨基和叔氨基的dmpda被用作独家沉积方法的合适候选物。在Ag/TiO（Ag重量比分别为2、4、8和16 wt%）的情况下，Ag NPs的数均粒径分别为6.4、8.4、11.8和15.2 nm。据我们所知，所制备的Ag/TiO样品在由Ag NPs催化的将4-硝基苯酚加氢还原为4-氨基苯酚的模型反应中表现出最高的催化能力之一。
