Nanoheterojunction Engineering Enables NIR‐II‐Triggered Photonic Hyperthermia and Pyroelectric Catalysis for Tumor‐Synergistic Therapy

Abstract Photodynamic therapy (PDT) as a non‐invasive strategy shows high promise in cancer treatment. However, owing to the hypoxic tumor microenvironment and light irradiation‐mediated rapid electron–hole pair recombination, the therapeutic efficacy of PDT is dramatically discounted by limited reactive oxygen species (ROS) generation. Herein, a multifunctional theranostic nanoheterojunction is rationally developed, in which 2D niobium carbide (Nb 2 C) MXene is in situ grown with barium titanate (BTO) to generate a robust photo‐pyroelectric catalyst, termed as BTO@Nb 2 C nanosheets, for enhanced ROS production, originating from the effective electron–hole pair separation induced by the pyroelectric effect. Under the second near‐infrared (NIR‐II) laser irradiation, Nb 2 C MXene core‐mediated photonic hyperthermia regulates temperature variation around BTO shells facilitating the electron–hole spatial separation, which reacts with the surrounding O 2 and H 2 O molecules to yield toxic ROS, achieving a synergetic effect by means of combinaterial photothermal therapy with pyrocatalytic therapy. Correspondingly, the engineered BTO@Nb 2 C composite nanosheets feature benign biocompatibility and high antitumor efficiency with the tumor‐inhibition rate of 94.9% in vivo, which can be applied as an imaging‐guided real‐time non‐invasive synergetic dual‐mode therapeutic nanomedicine for efficient tumor nanotherapy.