LAUSR

Photothermal cancer therapy demands nanomaterials with specific traits, including selective absorption of biotransparent near‐infrared (NIR) light, efficient light‐to‐heat conversion, biocompatibility, dispersibility, and prolonged temporal stability. These desirable properties are achieved by synthesizing Mo2C nanoparticles via an environmentally friendly femtosecond‐laser ablation method. Mo2C flakes are dispersed in water and treated with different laser powers for different durations. This process produces Mo2C nanoparticles in a single step in 10 min with water as the only additional material, forming stable colloidal solutions with no contaminants or hazardous waste. Structural and compositional characterization indicates laser‐induced amorphization of the nanoparticles, including gradual oxidation that enhances NIR light absorption. Notably, the Mo2C nanoparticle solution prepared using a 1.6‐W laser power in 10 min demonstrates photothermal conversion efficiencies exceeding 45% and 50% and temperature increases of 21 and 22 °C when illuminated with biotransparent 800 and 1064 nm NIR light, respectively. Furthermore, the solution exhibits exceptionally stable photothermal behavior over 6 months. These Mo2C nanoparticles, prepared by a rapid and clean laser manufacturing method, hold great promise for advancing photothermal therapy to combat cancer noninvasively.