Revealing Mn doping effect in transition metal phosphides to trigger active centers for highly efficient chemodynamic and NIR-II photothermal therapy

The alternation local electron density of atoms is an essential factor that determines its chemical properties. Herein, we reported a facile doping strategy, which can regulate the electron density of reaction center atoms and further enhance the Fenton activity. Typically, we have doped Mn elements in phosphides (Fe2P) and constructed the core–shell structure (denoted as Fe2[email protected]0.1Fe0.9P). The incorporation of Mn can obviously change the electron density of Fe2P, leading to the altered electron cloud density, significantly improving the catalytic activity of Fe atom, and further boosting the ∙OH yield by 4-folds. These can be verified by High-Resolution Transmission Electron Microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Electron Spinning Resonance (ESR) results. In addition, due to the strong absorbance in the NIR-II region, Fe2[email protected]0.1Fe0.9P can also generate the hyperthermia under the NIR-II irradiation, which can further enhance the Fenton reaction. The unique concept of doping strategy proposed in this work can broaden the horizons and impart new heights for the design of potential nanoagents towards cancer treatment.