Built-in electric field in covalent triazine framework grafted carbon nitride to boost piezocatalytic hydrogen peroxide production under ambient conditions

Piezocatalysis is a promising method for sustainable chemical synthesis through mechanical energy to chemical energy transformation. However, its practical development is limited by low charge separation efficiency. Here, we present a carbon nitride (C₃N₄)/ covalent triazine frameworks (CTFs) (C₃N₄/CTF-HC-2) system with enhancing interfacial electric field (IEF), for high-performance piezocatalytic production of hydrogen peroxide (H₂O₂). In pure water, the optimized catalyst demonstrates a H₂O₂ production rate of 4.98 mmol g⁻¹ h⁻¹ under ultrasound, which is 4.6 and 8.9 times greater than that of CTF-HC-2 and C₃N₄, respectively. This excellent performance is attributed to the strong IEF at the C₃N₄/CTF-HC-2 interface, which is calculated to be 1.71 times stronger than that of C₃N₄. This promotes rapid charge separation and abundant pyridine nitrogen sites enhance oxygen activation. Thus, the synergistic effect between IEF and piezocatalytic polarization realizes the overall H₂O₂ production, offering a new strategy for enhancing charge transfer in piezocatalysis through IEF.