NIR‐II‐Photopyroelectric Catalysis for Immunoactivation/Ferroptosis Combined Therapy of Tumor

Second near-infrared (NIR-II) light is desired to drive photocatalytic therapy owing to its high tissue penetrability and operationality, but the efficiency of direct NIR-II-photocatalytic H₂ generation is negligible owing to a trade-off between narrow semiconductor bandgap and high redox potential. Here, this work proposes a new concept of photothermal-pyroelectric cascade catalysis (photopyroelectric catalysis) to circumvent the trade-off for enhanced NIR-II light-driven catalytic efficiency, and develop a novel kind of multifunctional ZnS:Cu nanoparticles with a wide bandgap (2.7 eV) and high NIR-II-photothermal (52.4%) and pyroelectric efficiencies (0.44 mC m^-2 K^-1), realizing high efficacy of NIR-II light-driven catalytical H₂ generation (8.7 mmol g^-1 h^-1). Under NIR-II laser irradiation, intratumoral ZnS:Cu nanoparticles locally utilize thermal energy during both photothermal heating and natural cooling for pyroelectrocatalytic H₂ generation and oxidative depletion of intratumorally overexpressed glutathione, which induce tumor immunoactivation and ferroptosis, respectively, achieving high-efficacy synergetic therapy of tumor. This work opens an avenue for exploiting NIR-II light for efficient catalysis in the fields of both solar energy and catalytic medicine.