N,S-rGO/NiFe2O4 as an effective photocatalyst for the reduction of nitroaromatic Compounds to the corresponding aminoaromatics under visible light

Abstract

The accelerated pace of industrialization and the proliferation of diverse manufacturing sectors have led to significant environmental contamination, particularly by organic pollutants such as nitroaromatic compounds. Mitigating the associated ecological and toxicological impacts necessitates the development of environmentally benign strategies for their reduction to aminoaromatics. This study reports the synthesis of novel heterogeneous N,S co-doped reduced graphene oxide/ NiFe₂O₄ (N,S-rGO/NiFe₂O₄) nanocomposites via a one-step hydrothermal method. This approach simultaneously incorporates nitrogen and sulfur dopants into the graphene oxide matrix and integrates NiFe₂O₄ nanoparticles within the graphene layers. The structural, morphological, optical, and photocatalytic properties of the nanocomposites were systematically characterized using a comprehensive array of analytical techniques. The results confirm the successful co-doping of nitrogen and sulfur into the graphene oxide framework and the effective immobilization of NiFe₂O₄ nanoparticles onto the rGO surface. Notably, the synthesized nanocomposites exhibited outstanding photocatalytic activity under visible light, achieving complete reduction of nitrobenzene to aniline with 100 % conversion efficiency within 45 min, using hydrazine monohydrate as the hydrogen donor. Moreover, the photocatalyst demonstrated excellent stability and reusability, maintaining consistent catalytic performance over six consecutive cycles without any detectable loss in material integrity or conversion efficiency.