Organic-Base-Driven Intercalation and Delamination for the Production of Functionalized Titanium Carbide Nanosheets with Superior Photothermal Therapeutic Performance.

The delamination of titanium carbide sheets, an intriguing class of two-dimensional materials, has been critically dependent on the extraction of interlayer Al in acidic media, such as concentrated hydrofluoric acid (HF) or a mixture of hydrochloric acid (HCl) and a fluoride salt. Herein, we report an organic-base-driven intercalation and delamination of titanium carbide that takes advantage of the amphoteric nature of interlayer Al. The resulting aluminum-oxoanion-functionalized titanium carbide sheets manifested unusually strong optical absorption in the near-infrared (NIR) region with a mass extinction coefficient as high as 29.1 L g-1  cm-1 at 808 nm. Thus, the performance of this material is comparable or even superior to that of state-of-the-art photoabsorption materials, including gold-based nanostructures, carbon-based materials, and transition-metal dichalcogenides. Preliminary studies show that the titanium carbide sheets serve as efficient photothermal agents against tumor cells.