Construction of visible-light-induced Fe2O3/g-C3N4 nanocomposites for the enhanced degradation of organic dyes: Optimization of operative parameters

Abstract

This research aims to develop the highly promising Fe₂O₃/g-C₃N₄ photocatalyst through hydrothermal techniques to cope with the elevated amounts of bromophenol blue (BPB) dye in wastewater. The morphological studies were carried out by SEM analysis, while the crystallinity, structural behavior, and oxidation states of the prepared materials were determined by XRD, FTIR, and XPS analysis. The hydrodynamic size, surface area, and magnetic characteristics of the constructed materials were assessed through DLS, BET, and VSM analysis. The effectivity of the synthesized Fe₂O₃ and Fe₂O₃/g-C₃N₄-30 photocatalysts was appraised by the abatement of BPB under visible light radiation for 48 min. The results have shown an excellent degradation efficacy of Fe₂O₃/g-C₃N₄-30 photocatalyst with 98.39 % of BPB removal and a rate constant of 0.0757 min⁻¹, which was much higher than Fe₂O₃ photocatalyst with 79.64 % of removal and a rate constant of 0.0335 min⁻¹ under optimum conditions. The enhancement in degradation efficiency of the Fe₂O₃/g-C₃N₄-30 was due to the large surface area of Fe₂O₃/g-C₃N₄-30 (106.94 m²/g) as a result of g-C₃N₄ inclusion in the material, while the pure Fe₂O₃ unveiled a surface area of 89.67 m²/g. The impact of different reaction parameters on BPB degradation was also investigated, while the contribution of free radicals was corroborated through radical trapping experiments. The Fe₂O₃/g-C₃N₄-30 exhibited tremendous stability for repeated applications, with a loss of 8.03 % in efficiency after five consecutive experiments because of its easy magnetic separation. The experimental results have shown that synthesized Fe₂O₃/g-C₃N₄-30 photocatalysts could be used for the effective degradation of BPB from wastewater.