Phenanthroline bridging graphitic carbon nitride framework and Fe (II) ions to promote transfer of photogenerated electrons for selective photocatalytic reduction of Nitrophenols

Nitrophenols (NPs) are widely used in industries and highly toxic to ecological environment and human health. Because aminophenols (APs) are important chemicals, catalytic reduction of NPs via efficient and environment-friendly strategies is of great importance. Herein, we developed a green photocatalysis route to efficiently convert NPs to APs using a Fe (II) modified graphitic carbon nitride (g-C3N4) photocatalyst, where phenanthroline units were employed to bridge Fe (II) and carbon nitride framework. The optimized sample P-CN-8-Fe presented significantly improved absorption of visible light, separation of photogenerated charges and carrier transportation in comparison with the pristine g-C3N4 and the modified samples of CN-Fe and P-CN-8. Accordingly, the P-CN-8-Fe showed a high conversion (97%) of p-nitrophenol (p-NP) to p-aminophenol (p-AP) under 2 h visible light irradiation, and meanwhile possessed high photocatalytic durability. Its high activity was also demonstrated through photocatalytic reduction of other NPs and nitrobenzene compounds. Finally, a possible mechanism was proposed for the photocatalytic reduction of p-NP by P-CN-8-Fe. This work provides an effective approach to prepare Fe (II) modified g-C3N4 through the bridging effect of phenanthroline group, which is a potential visible light driven photocatalyst for reduction of nitrobenzene derivatives. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

In this study, a green photocatalysis route was developed using a Fe (II) modified graphitic carbon nitride photocatalyst to efficiently convert Nitrophenols (NPs) to aminophenols (APs) with high conversion and durability. The optimized sample showed significantly improved absorption of visible light and separation of photogenerated charges, demonstrating its potential as a visible light driven photocatalyst for reduction of nitrobenzene derivatives.