MOF etching and hydrogel confinement: a dual strategy for high-performance MOF-based synergistic piezo-photocatalysis

The synergistic piezoelectricity with photocatalysis in metal-organic frameworks (MOFs) presents a promising avenue for enhancing catalytic performance, yet it is often hampered by insufficient piezoelectric response and the inherent structural fragility of MOFs. Herein, we report a dual strategy to significantly boost the piezoelectric catalytic efficiency of MOFs. Through a morphology regulation with etching process, a hollow box-like MOF presents a higher structural asymmetry and greater deformation under internal stress, which markedly enhances the piezoelectric polarization. Meanwhile, to address the low recovery of powder-based catalysts, the optimized MOFs are embedded within a robust hydrogel matrix, effectively preventing structural disintegration and enabling excellent reusability with 20-cycle efficient degradation. Its catalytic efficacy is also validated in real industrial wastewater (with 97.1 % degradation rate), underscoring its potential for practical environmental remediation. This work not only provides a strategy to enhance the piezoelectricity of MOFs but also provides a solution to significantly improve the recyclability and lifespan of the powder catalysts.