Preparation of 2D Polyaniline/MoO_3−x Superlattice Nanosheets via Intercalation-Induced Morphological Transformation for Efficient Chemodynamic Therapy

Organic intercalation of layered nanomaterials is an attractive strategy to fabricate organic/inorganic superlattices for a wide range of promising applications. However, the synthesis of 2D organic/inorganic superlattice nanosheets remains a big challenge. Herein, the preparation of 2D polyaniline/MoO_3−x (PANI/MoO_3−x) superlattice nanosheets via intercalation-induced morphological transformation from MoO₃ nanobelts, as efficient Fenton-like reagents for chemodynamic therapy (CDT), is reported. Micrometer-long MoO₃ nanobelts are co-intercalated with Na⁺/H₂O followed by the guest exchange with aniline monomer for in situ polymerization to obtain PANI/MoO_3−x nanosheets. Intriguingly, the PANI intercalation can induce the morphological transformation from long MoO₃ nanobelts to 2D PANI/MoO_3−x nanosheets along with the partial reduction of Mo⁶⁺ to Mo⁵⁺, and generation of rich oxygen vacancies. More importantly, thanks to the PANI intercalation-induced activation, the PANI/MoO_3−x nanosheets exhibit excellent Fenton-like catalytic activity for generation of hydroxyl radical (·OH) by decomposing H₂O₂ compared with the MoO₃ nanobelts. It is speculated that the good conductivity of PANI can facilitate electron transport during the Fenton-like reaction, thereby enhancing the efficiency of CDT. Thus, the polyvinylpyrrolidone-modified PANI/MoO_3−x nanosheets can function as Fenton-like reagents for highly efficient CDT to kill cancer cells and eradicate tumors.