Improving Interface Matching in MOF-on-MOF S-Scheme Heterojunction through pi-pi Conjugation for Boosting Photoelectric Response

Accelerating the migration of interfacial carriers ina heterojunctionis of paramount importance for driving high-performance photoelectricresponses. However, the inferior contact area and large resistanceat the interface limit the eventual photoelectric performance. Herein,we fabricated an S-scheme heterojunction involving a 2D/2D dual-metalloporphyrinmetal-organic framework with metal-center-regulated CuTCPP-(Cu)/CuTCPP-(Fe)through electrostatic self-assembly. The ultrathin nanosheet-likearchitectures reduce the carrier migration distance, while the similarporphyrin backbones promote reasonable interface matching through pi-pi conjugation, thereby inhibiting the recombinationof photogenerated carriers. Furthermore, the metal-center-regulatedS-scheme band alignments create a giant built-in electric field, whichprovides a huge driving force for efficient carrier separation andmigration. Coupling with the biomimetic catalytic activity of CuTCPP-(Fe),the resultant heterojunction was utilized to construct photoelectrochemicaluric acid biosensors. This work provides a general strategy to enhancephotoelectric responses by engineering the interfacial structure ofheterojunctions.