Ultrathin Near‐Infrared Light Activated Nano‐Hotplate Catalyst

Abstract 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 KNdF₄ nanoplates consisting of 3–4 unit cell layers are prepared where the Nd³⁺ 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 Nd³⁺. 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 Nd³⁺ catalytic sites for reaction. The reaction kinetics are enhanced by the photothermal effect, leading to the observed > 10‐fold increase in product yields.