Visible-light-induced photocatalytic reductive carbonylation of nitroarenes using formic acid as a hydrogen source over a water-dispersible CTF-based palladium catalyst

Abstract

In the present study, Pd nanoparticles (NPs) supported on α-Fe₂O₃-decorated melamine-based COFs (Pd/α-Fe₂O₃@CTF) were employed as photocatalysts for water-mediated photocatalytic one-pot reductive N-formylation of nitroarenes using HCOOH as a sustainable hydrogen and formylation source under visible light irradiation. The desired products were obtained in good to excellent yields at room temperature. The high photocatalytic performance over Pd/α-Fe₂O₃@CTF was ascribed to redshift absorption in the visible-light region compared to pure CTF, resulting in the enhancement of photocatalytic activity under visible light. By combining CTF with inorganic semiconductor α-Fe₂O₃, which has significant and widespread visible light absorption, a hybrid heterostructure that increases the photocatalytic activity can be created. Moreover, Pd incorporation can also boost the photogenerated electron–hole separation efficiency. Pd/α-Fe₂O₃@CTF was found to be photostable and could be reused five times without any loss of its activity.