Electrochemical and Catalytic Efficiency of Green-Synthesized Fe, Ti, and Mixed Fe-Ti Nanoparticles

Catalysts play a crucial role in many chemical reactions, and the synthesis of green catalysts that are economical, selective, and active is important in addressing environmental pollution, a persistent global problem. This study investigates the electrochemical behavior and catalytic efficiency of green-synthesized iron-titanium (Fe-Ti) nanoparticles (NPs) for dye degradation. Three distinct types of NPs were synthesized using an environmentally friendly green approach with dextrose as the reducing agent: pure Fe NPs, pure Ti NPs, and mixed Fe-Ti NPs. The synthesized NPs were characterized using FTIR, XPS, XRD, SEM, and EDS to determine their structural, morphological, and chemical properties, and their redox behavior was evaluated by cyclic voltammetry (CV). Characterizations identified the Fe component as a mixed-valence, chloride-bearing Fe (oxyhydr)oxide most consistent with an akaganeite-type (β-FeOOH) phase and the Ti component as an amorphous Ti⁴⁺ titania, with the mixed material containing a minor, well-dispersed Fe (oxyhydr)oxide component that preserves accessible Fe³⁺/Fe²⁺ redox activity within the amorphous titania framework. Cyclic voltammetry studies showed that the mixed Fe-Ti NPs possessed the largest electroactive response, with an enclosed voltammetric area of 22.20 µA·V compared with 18.85 and 14.20 µA·V for the Ti and Fe NPs, together with the narrowest polarization gap, indicating the largest overall electrochemical response. The catalytic performance was evaluated through methyl orange (MO) dye degradation followed by UV-Vis spectroscopy, using hydrogen peroxide (H₂O₂) as the oxidant with the NPs acting as heterogeneous catalysts in a Fenton-like advanced oxidation process. The mixed Fe-Ti NPs degraded 77.5% of the dye within 60 min, substantially exceeding the Ti NPs (45.1%), the Fe NPs (30.8%), and the catalyst-free control (3.4%). This enhancement is attributed to the combined action of the two components, in which the amorphous titania framework disperses and stabilizes redox-active Fe³⁺/Fe²⁺ centers, coupling the enhanced electrochemical response directly to the Fenton-like generation of reactive radicals that drive dye degradation. These findings show that green-synthesized mixed Fe-Ti NPs represent a promising, dextrose-mediated approach for environmental remediation, particularly in wastewater treatment involving organic dye pollutants.