Chirality‐Driven Piezocatalysis in MOFs: Achieving Efficient Cocatalyst‐Free Hydrogen Evolution

Metal–organic frameworks (MOFs) have emerged as promising catalysts for energy conversion, yet their application in piezocatalysis is severely hindered by intrinsically high symmetry, which leads to a weak piezoelectric response. Herein, we report a chirality‐driven post‐synthetic modification strategy to enhance the piezoelectricity of MOF‐808(Hf) by grafting chiral L‐histidine (L‐His) onto Hf 6 clusters. Compared with MOF‐808(Hf), MOF‐808(Hf)‐His exhibits a significantly enhanced piezoelectric response, with the d 33 coefficient increasing from 44.2 to 108.8 pm/V. This enhancement is attributed to the introduction of L‐His, which breaks the structural symmetry and introduces the C═N bond as a highly stress‐sensitive polarization center. Consequently, a stronger built‐in electric field is generated under mechanical stress, promoting efficient charge separation and migration. Meanwhile, the grafted L‐His lowers the hydrogen evolution barrier, with Δ G H* decreasing from 0.46 to 0.37 eV, and further to 0.32 eV under stress. Consequently, without any cocatalyst, MOF‐808(Hf)‐His achieves an exceptional piezo‐catalytic H 2 evolution rate of 5215.70 µmol g −1 h −1 , 23‐fold higher than that of MOF‐808(Hf), and the highest among all reported MOF‐based piezo‐catalysts. This work establishes a robust chirality‐driven approach to overcome the intrinsic limitations of MOFs in piezocatalysis, offering a versatile pathway for sustainable hydrogen production from mechanical energy.