Structural regulation of Ti₃C₂ 2D-nanosheets for enhancing photothermal and electrochemical catalytic properties

Two-dimensional (2D) MXene materials are promising candidates for the development of heterogeneous materials, yet deciphering structural impacts on their inherent physical properties poses significant challenges. We introduce structurally regulated 2D Ti₃C₂ nanosheets that were fabricated using high intensity focused ultrasound (HIFU) method. These nanosheets were easily produced in large quantities with a high yield of 94.4% and exhibited excellent photothermal and electrochemical catalytic properties. By utilizing this monolayer H-Ti₃C₂ (HIFU-treated Ti₃C₂), the heterogeneous integration exhibited promising performance in subsequent applications. By integrating with a hydrogel matrix (H-Ti₃C₂, 0.1 wt.%), it demonstrated a photothermal conversion efficiency reaching 43.08%, and the maximum temperature increased by 48.14% under near-infrared (NIR) irradiation. Additionally, these 2D nanosheets were also utilized in fabricating electrochemical sensors to evaluate electrochemical-catalytic capabilities. Notably, it confirmed that the electrocatalytic activity of heterogeneous Au/H-Ti₃C₂ in electrochemical dopamine (DA) detection, and it proved the exhibition of sensitivity (0.012 μA/μM), low detection limit (0.15 μM), and excellent anti-interference performance and stability. The enhanced activity was ascribed to synergistic effect of Au and the increased number of accessible active sites on the nanosheets. This work not only sheds light on the structure–property relationship of 2D Ti₃C₂ but also broadens the application scope of typical dimensional materials for controlling and producing in biological and sensing applications.