Preparation of Ultrathin Two-Dimensional Tix Ta1-x Sy Oz 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, Ti_x Ta_1-x S_y O_z (x=0.71, 0.49, and 0.30), from Ti_x Ta_1-x S₂ 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.

Keywords: anti-cancer agents; hybrid nanosheets; photothermal therapy; titanium; two-dimensional structures.