Wu Xiangyang, Yeow Edwin K L
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Small. 2020 Oct;16(40):e2002698. doi: 10.1002/smll.202002698. Epub 2020 Sep 6.
A combined photothermal-catalytic system that contains a single active element, without using different entities for separate roles (catalytic vs photothermal), is designed here for efficient catalytic reactions. Herein, ultrathin (sub-6 nm) rectangular-like KNdF nanoplates consisting of 3-4 unit cell layers are prepared where the Nd ions act as a Lewis acid catalyst. In addition, the nanoplates undergo light-to-heat conversion when irradiated with NIR light due to cross-relaxation and nonradiative relaxation processes from excited Nd . The cyanosilylation of a series of ketones is performed using the nano-hotplate catalysts to give near quantitative yields of the cyanohydrin trimethylsilyl ethers. This is because of the high surface area-to-volume ratio of the thin nanoplates that provides a large number of surface Nd catalytic sites for reaction. The reaction kinetics are enhanced by the photothermal effect, leading to the observed > 10-fold increase in product yields.
本文设计了一种组合式光热催化系统,该系统包含单一活性元素,无需使用不同实体来分别承担催化和光热作用,以实现高效催化反应。在此制备了由3 - 4个晶胞层组成的超薄(小于6纳米)矩形KNdF纳米片,其中Nd离子充当路易斯酸催化剂。此外,由于激发态Nd的交叉弛豫和非辐射弛豫过程,纳米片在近红外光照射下会发生光热转换。使用纳米热板催化剂对一系列酮进行氰基硅烷化反应,得到了近乎定量产率的氰醇三甲基硅基醚。这是因为薄纳米片的高表面积与体积比为反应提供了大量表面Nd催化位点。光热效应增强了反应动力学,导致观察到产物产率提高了10倍以上。