Linkage Engineering for Regulating the Photocatalytic Performance of TpTt-COF and Carbon Nitride Heterojunctions

The rational design of photocatalysts through linkage engineering and heterojunction construction has emerged as an effective approach to enhance photocatalytic performance. In this work, linkage-engineered strategies were applied to heterojunctions based on TpTt-COF and g-C₃N_x to investigate how different interfacial forces- covalent bonds, π-π stacking, and hydrogen bonds- influence charge transfer and photocatalytic activity. The results reveal that the heterojunction connected via covalent linkage exhibits superior performance in both H₂O₂ generation and pollutant degradation, compared to those formed by weaker interactions. This enhancement is attributed to the shortened electron transport pathway and accelerated interfacial charge transfer, as supported by DFT calculations, which demonstrate the presence of an internal electric field and charge redistribution driving efficient carrier migration. Furthermore, the photocatalyst was further evaluated under simulated environmental conditions to assess its practical application potential. This study highlights the key role of interfacial linkage chemistry in regulating charge dynamics and provides a rational design principle for constructing efficient, metal-free heterojunction photocatalysts for sustainable environmental and energy applications.