Kinerja Fotokatalisis Fe/TiO2 Nanonotube (fe/TNT) Terhadap Remazol Red Dye Dengan Pengaruh Variasi Dosis Dopan Fe3+

Abstract

The chemical composition of Remazol Red, a synthetic dye, comprises a stable azo structure, which renders it resistant to natural degradation and potentially hazardous to the environment. One method that can be applied to address this issue is photocatalysis using Fe³⁺-doped TiO₂ nanotubes (Fe/TNT). The present study aims to determine the effect of varying Fe³⁺ dopant concentrations on the adsorption and photocatalytic activity of Fe/TiO₂ nanotubes (Fe/TNT) in degrading Remazol Red, as well as to evaluate the effects of pH, catalyst dosage, and reusability on photocatalytic performance. The synthesis of Fe/TNT was accomplished through the utilisation of the hydrothermal method, employing Fe dopant concentrations ranging from 0 to 2%. The adsorption and photocatalytic activities of the samples were examined using a 25 mg/L Remazol Red solution, with illumination provided by a 100-watt visible-light LED lamp. Variations in Fe dopant concentration, pH, catalyst dosage, and reusability were systematically investigated. The results demonstrated that variations in Fe dopant concentration influenced the adsorption and photocatalytic activities of Fe/TNT. The Fe/TNT sample, with a composition of 1%, demonstrated optimal performance, exhibiting an adsorption time of 30 minutes and a photocatalytic time of 90 minutes, resulting in a removal efficiency of 34.63%. This increase in activity was supported by the highest specific surface area of 134.02 m²/g, well-preserved nanotube morphology, a dominant anatase phase, and a reduction in the bandgap energy to 2.89 eV. The optimal photocatalytic conditions were achieved at a pH of 3, with a removal efficiency of 38.26%, and at a catalyst dose of 100 mg (4 g/L), with a removal efficiency of 50.08%. Reusability tests demonstrated that 1% Fe/TNT retained its photocatalytic activity up to the fifth cycle, exhibiting a removal efficiency of 42.09%. The findings of this study suggest that 1% Fe/TNT is the most effective dopant composition and has the potential to be utilised as a visible-light-based photocatalyst for the degradation of Remazol Red in synthetic dye wastewater.