Unprecedented Piezo‐Photocatalytic H ₂ O ₂ Synthesis via Synergy of Dual Charge Transfer Channels and Frustrated Lewis Pairs in Bi‐Ionic Carbon Nitride

The efficient synthesis of hydrogen peroxide (H 2 O 2 ) through piezo‐photocatalysis is a promising yet challenging sustainable route, primarily limited by inefficient charge separation and sluggish surface reaction kinetics. This study introduces an innovative bi‐ionic (K + /Ca 2+ ) co‐doping strategy to engineer graphitic carbon nitride, creating a high‐performance catalyst for H 2 O 2 production. The bi‐ionic doping structure, combined with introduced cyano groups, constructs multi‐charge transfer channels and significantly enhances the piezoelectric polarization field, which dramatically promotes the directional separation and migration of photogenerated charge carriers. More importantly, the Ca 2+ sites and adjacent N‐cyano groups form synergistic Frustrated Lewis pairs, which simultaneously facilitate spontaneous ethanol dissociation to supply protons and strongly adsorb and activate O 2 molecules. Consequently, the optimized catalyst shows an exceptional piezo‐photocatalytic H 2 O 2 production rate of 24.95 mmol g −1 h −1 under visible light and ultrasound, significantly outperforming most reported analogues. Furthermore, we fabricated shape‐tunable hydrogels by integrating the catalyst with Sil‐MA, which not only facilitates catalyst recovery but also creates a beneficial gas‐solid interface when coated on floating substrates. The floating hydrogel system maintains stable H 2 O 2 production, demonstrating great potential for practical applications. This work provides valuable insights into designing efficient piezo‐photocatalytic systems for sustainable chemical synthesis.