Highly Efficient 2D NIR‐II Photothermal Agent with Fenton Catalytic Activity for Cancer Synergistic Photothermal–Chemodynamic Therapy

Photothermal therapy (PTT) has emerged as a promising cancer therapeutic modality with high therapeutic specificity, however, its therapeutic effectiveness is limited by available high‐efficiency photothermal agents (PTAs), especially in the second near‐infrared (NIR‐II) biowindow. Here, based on facile liquid‐exfoliated FePS₃ nanosheets, a highly efficient NIR‐II PTA with its photothermal conversion efficiency of up to 43.3% is demonstrated, which is among the highest reported levels in typical PTAs. More importantly, such Fe‐based 2D nanosheets also show superior Fenton catalytic activity facilitated by their ultrahigh specific surface area, simultaneously enabling cancer chemodynamic therapy (CDT). Impressively, the efficiency of CDT could be further remarkably enhanced by its photothermal effect, leading to cancer synergistic PTT/CDT. Both in vitro and in vivo studies reveal a highly efficient tumor ablation under NIR‐II light irradiation. This work provides a paradigm for cancer CDT and PTT in the NIR‐II biowindow via a single 2D nanoplatform with desired therapeutic effect. Furthermore, with additional possibilities for magnetic resonance imaging, photoacoustic tomography, as well as drug loading, this Fe‐based 2D material could potentially serve as a 2D “all‐in‐one” theranostic nanoplatform.