Hematite/Graphitic Carbon Nitride Nanofilm for Fenton and Photocatalytic Oxidation of Methylene Blue

Abstract

Hematite (α-Fe2O3)/graphitic carbon nitride (g-C3N4) nanofilm catalysts were synthesized on fluorine-doped tin oxide glass by hydrothermal and chemical vapor deposition. Scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses of the synthesized catalyst showed that the nanoparticles of g-C3N4 were successfully deposited on α-Fe2O3 nanofilm. The methylene blue degradation efficiency of the α-Fe2O3/g-C3N4 composite catalyst was 2.6 times greater than that of the α-Fe2O3 single catalyst under ultraviolet (UV) irradiation. The methylene blue degradation rate by the α-Fe2O3/g-C3N4 catalyst increased by 6.5 times after 1 mM of hydrogen peroxide (H2O2) was added. The photo-Fenton reaction of the catalyst, UV, and H2O2 greatly increased the methylene blue degradation. The results from the scavenger experiment indicated that the main reactants in the methylene blue decomposition reaction are superoxide radicals photocatalytically generated by g-C3N4 and hydroxyl radicals generated by the photo-Fenton reaction. The α-Fe2O3/g-C3N4 nanofilm showed excellent reaction rate constants at pH 3 (Ka = 6.13 × 10−2 min−1), and still better efficiency at pH 7 (Ka = 3.67 × 10−2 min−1), compared to other methylene blue degradation catalysts. As an immobilized photo-Fenton catalyst without iron sludge formation, nanostructured α-Fe2O3/g-C3N4 are advantageous for process design compared to particle-type catalysts.

Synthesis and Characterization of an α-Fe2O3-Decorated g-C3N4 Heterostructure for the Photocatalytic Removal of MO

“…MO degradation was significantly suppressed when BQ was utilized as a scavenger. Thus, the results of the trapping experiments clearly demonstrate that the hydroxyl radical (•OH) and hole (h + ) play a minor role in the photocatalytic removal of MO, whereas, O2 •− is the primary ROS that further degrades the MO over the g-C3N4/α-Fe2O3 nanocomposite, which is in good agreement with recent studies [44][45][46][47].…”

Breaking Polymer Chains with Self‐Propelled Light‐Controlled Navigable Hematite Microrobots

“…[ 30,31 ] It also catalyzes Fenton and photo‐Fenton reactions with UV‐light irradiation and H 2 O 2 , producing more ROS to attack pollutants in water. [ 32 ] These characteristics make it an appealing material for the fabrication of visible light‐powered micro/nanorobots for water remediation. However, hematite photocatalytic applications are limited by its high electron–hole recombination rate and low electron mobility.…”

Engineered magnetic oxides nanoparticles as efficient sorbents for wastewater remediation: a review

“…The results revealed that all prepared iron oxides with and without surfactants were formed in spherical α-Fe 2 O 3 with a diameter range of 15-205 nm based on the surfactant sort and concentration. As well many hematite composites were fabricated using a hydrothermal route, such as activated carbon/α-Fe 2 O 3 (Ermanda et al 2021), Co-doped α-α-Fe 2 O 3 (Cai et al 2021), α-Fe 2 O 3 /g-C 3 N 4 (Lee and Park 2020), and chitosan-coated-α-Fe 2 O 3 (Badry et al 2021).…”