Piezo-photocatalysis over high-nuclearity titanium-oxide cluster via lead heterocoordination enhances activity by piezoelectric effect

Piezoelectric materials usually exist in solid-state forms with obscure structures, hindering atomic-level understanding of structure-property relationships. Here, we report the piezoelectric high-nuclearity titanium-oxide molecular cluster, Ti₂₆Pb₁₀, constructed via a dopant metal coordination strategy. The cluster framework comprises 26 Ti atoms linked by binuclear units, with 10 Pb²⁺ ions anchored through distinct coordination: 2 embedded and 8 surface exposed. Ti₂₆Pb₁₀ displays a piezoelectric constant 5.5 times higher than PbTiO₃, as confirmed by piezoresponse force microscopy. Density functional theory simulations reveal stress-induced lattice distortion and bandgap shifts. Critically, leveraging piezo-photocatalytic synergy, Ti₂₆Pb₁₀ enables ultraefficient tetracycline degradation, achieving a rate 15 times faster than PbTiO₃ under combined light and ultrasound, with a superior synergy factor. Mechanistic studies indicate that local electric fields coupled with light excitation promote ¹O₂ generation. This work extends titanium-oxide clusters into piezo-photocatalysis and provides a rational design paradigm for multifield synergistic catalysis and atomic-level structure-activity insights.