The evaluation of the photocatalytic activity of magnetic and non-magnetic polymorphs of Fe 2 O 3 in natural sunlight exposure: A comparison of photocatalytic activity

Abstract

The non-magnetic and magnetic polymorphs of iron oxide (Fe 2 O 3 ) namely: α-Fe 2 O 3 (hematite) and γ-Fe 2 O 3 (maghemite) respectively, were synthesized by a facile surfactant aided hydrogel route. The synthesized polymorphs were characterized by diffuse reflectance, photoluminescence and raman spectroscopy for optical properties whereas the morphological, structural, chemical and electronic state evaluation were performed by FESEM, HRTEM, XRD, and XPS. The charge transport and the stability of the materials were examined electrochemically. The photocatalytic activity of the synthesized polymorphs was evaluated for the degradation of 2-chlorophenol and 2nitrophenol in the exposure of the visible region and complete spectrum natural sunlight.Both the polymorphs exhibited a significantly high activity for the degradation of the phenolic substrate in the exposure of the complete spectrum of sunlight, however, the activity in the visible region of the sunlight was relatively lower. A substantial increase in the activity in the visible region was noticed when the polymorphs were exposed to complete spectrum sunlight prior to the photocatalytic experiments. The comparison of the exposed and unexposed samples revealed the induction of defects that served as traps for the excited electrons and increased activity of the polymorphs.

Versatile Luminol/Dissolved Oxygen/Fe@Fe2O3 Nanowire Ternary Electrochemiluminescence System Combined with Highly Efficient Strand Displacement Amplification for Ultrasensitive microRNA Detection

“…21 The SAED patterns (Figure 1D) showed that four concentric rings corresponded to Fe 2 O 3 (440), Fe (110), Fe 2 O 3 (311), and Fe 2 O 3 (220) crystal planes. 22,23 Therefore, the above results suggested the successful preparation of Fe@Fe 2 O 3 nanowires.…”

“…In addition, the high-resolution TEM (HRTEM) images (Figure C) showed clear lattice fringes of 2.03 and 2.52 Å, which were the lattice spacings of Fe (110) and Fe 2 O 3 (311) planes, respectively . The SAED patterns (Figure D) showed that four concentric rings corresponded to Fe 2 O 3 (440), Fe (110), Fe 2 O 3 (311), and Fe 2 O 3 (220) crystal planes. , Therefore, the above results suggested the successful preparation of Fe@Fe 2 O 3 nanowires.…”

Photocatalytic decontamination of phenol and petrochemical wastewater through ZnO/TiO2 decorated on reduced graphene oxide nanocomposite: influential operating factors, mechanism, and electrical energy consumption

“…Recently, many semiconductors have been under usage as photocatalyst such as TiO 2 , ZnO, WO 3 , MgO, SiO 2 , Fe 2 O 3 , and CdS. [10][11][12][13][14][15][16] Semiconductor photocatalysts have recently demonstrated high photocatalytic activity for decontamination of organic compounds in aqueous solutions. Typically, titania has been revealed as a promising catalyst and has been widely used in photocatalytic degradation of organic contaminants due to its electrochemical properties, low cost, availability, high stability and non-toxicity.…”

Terrestrial solar radiation driven photodecomposition of ciprofloxacin in clinical wastewater applying mesostructured iron(III) oxide

“…At this point, it is rather unclear if a heterojunction due to slightly varying band positions between the two iron oxide polymorphs within the nanotubes is formed. Heterojunction formation would contribute favorably to charge carrier separation and therefore would be expected to improve photocatalytic activity of the α/γ-Fe 2 O 3 nanotubes as compared to the reference materials (Liu 2012 ; Aslam et al 2018 ).…”