Efficient remediation of nitroaromatics using polycarbazole-coated TiFe₂O₄ nanohybrids: A synergistic catalytic approach

• Synthesis of polycarbazole-decorated titanium ferrite nanohybrids • Enhanced catalytic performance due to synergistic interaction • Improvement in structural properties with increasing polycarbazole content. • High recyclability and stability, demonstrating potential for sustainable wastewater treatment The catalytic reduction of nitrophenol compounds to aminophenols is a key reaction for both environmental remediation and fine chemical synthesis. This study introduces, for the first time, polycarbazole-decorated titanium ferrite (TiFe₂O₄–PCz) nanohybrids synthesized via an in situ oxidative polymerization route, establishing a new catalytic platform for the efficient reduction of nitrophenol derivatives. The incorporation of PCz onto the ferrite surface yielded a uniform, conductive polymer layer that improved electron transport and prevented nanoparticle agglomeration. Structural and morphological analyses using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Field Emission Scanning Electron Microscopy (FE-SEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS) confirmed the successful formation of the TiFe₂O₄–PCz nanohybrid and the retention of the spinel structure. Catalytic studies demonstrated that the TiFe₂O₄–PCz nanohybrids exhibited superior performance in the sodium borohydride (NaBH₄)-assisted reduction of nitrophenol derivatives under ambient conditions. The enhanced catalytic efficiency was attributed to the synergistic interaction between the conductive PCz matrix and the active TiFe₂O₄ core, enabling rapid electron transfer and strong substrate adsorption. Kinetic analysis revealed that the reaction followed pseudo-first-order kinetics with respect to nitrophenol concentration, with rate constants significantly exceeding those of conventional metal-based catalysts. The TiFe₂O₄–PCz nanohybrid also demonstrated excellent reusability and stability over multiple reaction cycles, highlighting its potential as a sustainable and cost-effective catalyst for wastewater treatment and green chemical synthesis.