In Situ Assembly of Recyclable Polyoxometalate-Derived Photocatalysts for Sustainable Photocatalytic H₂ Generation

Polyoxometalate-derived photocatalysts with unique semiconductor-like performance and abundant catalytic sites are promising in photocatalysis. However, the cumbersome synthesis steps and complex structures of polyoxometalate-based compound carriers for photocatalysis pose significant challenges. In this study, we report two isostructural polyoxometalate-derived photocatalysts [M(H₂O)₄(TeMo₆O₂₄)][M(Hpca)(H₂O)₅]₂ · 6H₂O [M = Co (1), Zn (2)], in situ synthesized via iso-nicotinic acid (pca) as the organic ligand and Anderson-type polyoxometalate [TeMo₆O₂₄]^6- as the inorganic block, which enable heterogeneous photocatalytic H₂ production (3207.1 μmol g^-1 h^-1), far superior to most reported polyoxometalate-based heterogeneous systems. Moreover, compound 1, as a photocatalyst, displays excellent photocatalytic recyclability and stability. Density functional theory calculation reveals that the presence of the cobalt(II) ligand facilitates the H2 evolution reactions process, and the incorporation of M(Hpca)(H₂O)₅ further promotes the reaction. This work presents a versatile strategy for designing advanced polyoxometalate-based photocatalysts for sustainable photocatalytic H₂ generation.