Design of Piezoelectric, Hydrophobic, and Metal‐Free Porous Frameworks for High‐Rate Conversion of Water and Air to Hydrogen Peroxide

Production of hydrogen peroxide (H₂O₂) as a crucial chemical is important in modern industry. Considering its composition, directly conversion from water and oxygen is a sustainable route. Production process under the driven force of mechanism stimuli, namely piezocatalysis, is easy to operate, expensive electrode-free and light-independent. Current challenge of piezocatalysts lies in the limited hydrogen peroxide production. Porous aromatic frameworks (PAFs) are a class of porous materials constructed from covalently linked aromatic rings with adjustable framework chemistry and high tolerance in harsh conditions. However, PAFs are generally amorphous, and their electronic, photonic and other physical properties are less developed. To achieve piezoelectricity in PAFs, we designed short-range regular dipolar motifs as featured units to give the whole framework significant piezoelectric effect. In this work, the synthesized framework from unambiguous connecting manner of coupling reactions showed desired pizeocatalytic effect. The obtained piezoelectric PAFs converted water and air to H₂O₂ with a rate as high as 30694 µmol g^-1 h^-1. The groundbreaking production rate was achieved owing to the highly exposed active sites, band-structure-dependent corporative reaction pathways, metal-free composition and hydrophobicity of the PAFs designed in this study. This work first built piezoelectric catalysts in amorphous frameworks based on the definite connection of coupling reactions, and pave the way to the targeted design of PAFs functions for environmental water utilization.