Leveraging the Cooperative Photocatalysis for the Concurrent Production of Solar Fuels and Value-added Chemicals: Mediated by the Metal-free Porphyrin-based Polymeric Network

Abstract

Limitations in the conventional energy-intensive anthraquinone oxidation process for H2O2 production anticipated the researchers to come up with an environmentally sustainable, energy-efficient, and cost-effective approach. The photocatalytic H2O2 generation from molecular oxygen has emerged as a leading edge in sustainable technology development, yet efficiency remains a key challenge. Various sacrificial agents are added to the reaction medium to improve efficiency, but their underutilization is the primary concern. To combat this, we need to design a reaction system that considers the selective oxidation of the sacrificial agent along with the reduction of oxygen. On that note, we constructed a metal-free organic polymer Porp-Tz exhibiting broad visible light absorption, and suitable band positions that consider the efficient reduction of O2 for the co-production of H2O2 with a remarkable generation rate of 25.13 mmol g-1h-1 along with the synthesis of industrially important chemical N-benzylidenebenzylamine (AQY = 7.9 % at 420 nm). In addition, the concurrent production of regioselective 3,4-dihydroisoquinoline (DHIQs) from tetrahydroisoquinoline (THIQs), alongside the H2O2 generation rate of 13.34 mmol g-1h-1 was also explored. Moreover, the photocatalytic reaction mechanism highlights the synergistic role of the reactive oxygen species (O2.- and 1O2¬), h+, and proton donors providing a comprehensive understanding of the photocatalytic process. This study emphasizes new insights into deploying the next-generation multifunctional polymeric network for the photocatalytic co-production of solar fuel and the selective synthesis of fine value-added chemicals broadening the scope of porous organic polymers for potential industrial interest.