The synthesis and characterization of iron particles (Fe-Ps) derived from a reaction between dark tea extract and an iron precursor were investigated. FTIR and XRD analyses confirmed the interaction of iron with plant constituents and the amorphous nature of the Fe-Ps. The catalytic activity of the Fe-Ps sample on malachite green (MG) degradation in a Fenton system was evaluated, along with operational factors such as reaction time, Fe-Ps loading, MG concentration, and reusability. The experimental results showed a significant enhancement in degradation efficiency when H₂O₂ was combined with the synthesized Fe-Ps, compared to the individual use of H₂O₂. The degradation efficiency of MG by the synthesized Fe-Ps remained stable at 90% after five cycles, indicating good reusability. The decrease in degradation efficiency after the reusability process was attributed to several factors, including changes in the crystallite phase, the decrease in BET surface area, and the higher chloride content in the sample. The kinetic results demonstrated the suitability of the BMG model for describing the reaction between the synthesized Fe-Ps and MG in a Fenton system. The BMG model facilitated the determination of the superior reaction rate constant and degradation capacity. These findings provide valuable insights into the potential application of tea residues in the synthesis of metal particles.