Self-assembled all-organic pheophorbide A/g-C3N4 heterojunction for enhanced visible-light-driven photocatalytic degradation of bisphenol A

• An all-organic self-assembled PA/pCN heterojunction was successfully prepared by the electrostatic interaction strategy. • The interlaced band structure enables PA/pCN to exhibit internal electric field and π-electrons delocalization effects. • The PA/pCN heterojunction system generates many highly oxidative reactive species, such as •O 2 - , h + , and •OH. • The electrostatic and π-π interaction mechanism and the charge separation mechanism of the PA/pCN system was proposed. Emerging micropollutants bisphenol A (BPA) pose significant risks to the environment and human health. Photocatalysis shows promise for degrading micropollutants but faces challenges like secondary pollution and inefficiency in carrier separation particularly in all-organic photocatalyst systems. Herein, we successfully constructed an all-organic, self-assembled pheophorbide A/protonated g-C 3 N 4 (PA/pCN) heterojunction by electrostatic interaction . This nano-crystalline supramolecular semiconductor, PA, effectively interfaces with pCN nanosheets to form 0D/2D heterojunction utilizing a combination of electrostatic and π-π interactions. The well-arranged band structures and electrostatic interactions between PA and pCN contribute to the creation of internal electric field (IEF) and π-electrons delocalization effects. The broad spectral response of PA enhances the light absorption capacity of pCN, leading to the formation of an increased number of photogenerated carriers. As a result, the PA/pCN heterojunction generates a plethora of highly oxidative reactive species, such as superoxide radicals (•O 2 – ), photogenerated holes (h + ), and hydroxyl radicals (•OH), contributing significantly to its robust photocatalytic oxidation performance. The PA/pCN heterojunction is 2.5 times more efficient over pCN control at degrading BPA under visible light. The as developed all-organic pheophorbide A/protonated g-C 3 N 4 heterojunction self-assembly strategy offers a promising solution for utilizing photocatalytic technology to eliminate micropollutants in aquatic environments effectively.