Energy- and time-efficient synthesis method: immobilization of iron (III) oxide on wires via direct heating for organic dye and chromium (VI) ion removal

The immobilization of iron (III) oxide (Fe₂O₃) particles on substrates through methods such as low-pressure chemical vapor deposition, hydrothermal, or chemical bath processes often entails prolonged synthesis durations (in hours if not days), substantial equipment costs, and/or elevated operational expenses due to high electrical power consumption (in kW). Indeed, high electrical power consumption is directly associated with increased CO₂ emissions in the generation of electrical power, especially in regions where the energy relies heavily on fossil fuels. These synthesis methods are not favored for achieving Carbon Net Zero in the year 2050. Thus, the drawbacks pose significant impediments to the widespread industrial application of Fe₂O₃ particles as visible light-driven photocatalysts for treating organic effluents on a large scale. In this study, a rapid and innovative synthesis of Fe₂O₃ particles immobilized on wires within a mere 10-min timeframe and consuming low electrical power (50 W.h) was demonstrated. This was achieved by the development of a novel direct heating (DH) method. The influence of heating duration on the structural, morphological, and photocatalytic properties of Fe₂O₃ particles was investigated. These Fe₂O₃particles demonstrated positive photocatalytic activity, degrading 33.29% of Rhodamine B (RhB) dye and 81.4% of chromium Cr (VI) within 90 min under visible light irradiation. The good photocatalytic performance, coupled with the simplicity and cost-effectiveness of DH method, establishes a promising alternative for the development of visible light-active photocatalysts for the removal of both organic dyes and metal ions removal.