Two-dimensional inorganic semiconductor materials have aroused tremendous research interest and found their potential in resolving the present urgent global issues, such as cancer therapy and fresh water shortage. Particularly, the near-infrared (NIR) photothermal conversion efficiency is a significant parameter in photothermal therapy. However, lack of an effective improvement strategy and their relatively low NIR phothermal conversion efficiency would restrict their wide and further application. Here, this work reports that enhanced NIR photothermal conversion is achieved in topological Bi2Se3 nanosheets by introducing a lanthanide dopant. Specifically, lanthanide Pr-doped Bi2Se3 nanosheets possess a photothermal conversion efficiency of 49.5%, which is higher than those of undoped Bi2Se3 nanosheets (31.0%) and numerous reported photothermal materials. The electronic structure of Pr-doped Bi2Se3 nanosheets was also analyzed by first-principles simulation. Furthermore, an interfacial evaporation system based on the developed nanosheets has been established, demonstrating a superior solar-thermal conversion efficiency of 91.5% and a water evaporation rate of 1.669 kg m-2 h-1 under 1 sun irradiation. The present work would provide new insights for the increase in the efficiency of photothermal materials.
Keywords: 2D materials; bismuth selenide; lanthanide; photothermal; solar-driven water evaporation.