Preparation of Ultrathin Two-Dimensional Ti<inf>x</inf>Ta<inf>1−x</inf>S<inf>y</inf>O<inf>z</inf> Nanosheets as Highly Efficient Photothermal Agents

Abstract

Although two-dimensional (2D) metal oxide/sulfide hybrid nanostructures have been synthesized, the facile preparation of ultrathin 2D nanosheets in high yield still remains a challenge. Herein, we report the first high-yield preparation of solution-processed ultrathin 2D metal oxide/sulfide hybrid nanosheets, that is, TixTa1−xSyOz (x=0.71, 0.49, and 0.30), from TixTa1−xS2 precursors. The nanosheet exhibits strong absorbance in the near-infrared region, giving a large extinction coefficient of 54.1 L g−1 cm−1 at 808 nm, and a high photothermal conversion efficiency of 39.2 %. After modification with lipoic acid-conjugated polyethylene glycol, the nanosheet is a suitable photothermal agent for treatment of cancer cells under 808 nm laser irradiation. This work provides a facile and general method for the preparation of 2D metal oxide/sulfide hybrid nanosheets.