Phyto-Assisted Preparation of Fe₂O₃ Nanofins Using Elaeocarpus hygrophilus Leaves Extract/Cyano Group Modified Graphitic Carbon Nitride Nanosheets for Enhancing Photocatalytic Efficiency

In this study, iron oxide nanofins (Fe₂O₃ NFs) were synthesized using Elaeocarpus hygrophilus leaves extract and decorated on graphitic carbon nitride (gCN) substrate to form the Fe₂O₃/gCN composite, as a photocatalytic candidate to degrade Rhodamine B (RhB) and produce hydrogen peroxide (H₂O₂). The morphological, structural, electrochemical, and optical properties of Fe₂O₃/gCN were determined via analytical methods, including scanning electron microscopy, energy dispersive X-ray, scanning electron microscopy field emission, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), electrochemical impedance spectroscopy, and photocurrent repones. As a result, the band gap of Fe₂O₃/gCN was determined to be 2.79 eV through UV-DRS and Kubelka–Munk function, which is lower than that of pure gCN (2.82 eV). Such phenomenon provides an RhB photodegradation efficiency of 99.23% within 120 min at pH 4, as well as an H₂O₂ concentration of 4237.03 μM/g h under visible light radiation, over the 1.0Fe₂O₃/gCN sample. Further insights elucidate that ⋅O₂^– plays an important part in the photocatalysis, contributing to light-driven RhB degradation and H₂O₂ production. The catalytic performance of 1.0Fe₂O₃/gCN was also maintained after 4 consecutive cycles, which indicates a high potential for environmental remediation and cleaner production processes using light as the driving force.