Engineering of Schottky heterojunction in Ru@Bi2S3/Nb2C MXene based on work function with enhanced carrier separation for promoted sterilization

Within the illustrious and renowned MXene family, Niobium carbide (Nb2C) has astounded researchers by exhibiting an extraordinary level of photothermal conversion efficiency and photothermal stability, all while maintaining the possibility of biodegradability. However, the absence of band gaps hindered Nb2C as an attractive photoresponsive material for sterilization purposes. To overcome this obstacle, we engineered a Schottky heterojunction in Nb2C by introducing Ru and Bi2S3 based on the work function theory to generate an internal electric field (IEF) in Ru@Bi2S3/Nb2C, thus enhancing the photocatalytic sterilization performance by improving the charge transfer efficiency. The strategic doping of Ru also improved the carrier separation as an electron trap, apart from enhancing the light absorption efficiency by exploiting the Localized Surface Plasmon Resonance (LSPR). The results of Ultraviolet Photoelectron Spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) divulge the stark difference in work function, which facilitates the directional transfer of carrier and subsequently augments the formation of Schottky heterojunction. This unique structure which is beneficial to the generation of reactive oxygen species (ROS). As a result, the in vitro sterilizing efficiency of the Ru@Bi2S3/Nb2C exceeds 99.87%, and in vivo experiments demonstrated wound healing effects in mouse wound models. These results have confirmed the significant implications of Schottky heterojunction for the use of Nb2C in the biomedical sector.