Heart-shaped {Cu₁₀}-added polyoxometalates for visible-light-driven hydrogen evolution and photothermal conversion

A heart-shaped polyoxometalate, H₁₀LiK₅[(BO(OH)₂)₂(B₂O(OH)₆)Cu₁₀(OH)₄(H₂Ge₂W₂O₁₅)(GeW₉O₃₄)₂]·46H₂O (1), was successfully synthesized in this study. Its structure consists of a {B₄Cu₁₀} core integrated with {GeW₉} and {Ge₂W₂} fragments. Notably, the Cu–O–Cu bridge closure is indirectly precluded by steric hindrance originating from the specific orientation of the Jahn–Teller distortion, an unprecedented structural observation in polyoxometalate chemistry. 1 exhibits remarkable dual functionality, achieving a peak photocatalytic H₂ evolution rate of 8808.7 μmol·g⁻¹·h⁻¹ and photothermal conversion efficiency of 16.27% under 808 nm irradiation. These findings demonstrate the potential of 1 as a robust candidate for future synergistic solar energy conversion and photothermal applications.