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Hierarchical Fe2O3 nanorods/TiO2 nanosheets heterostructure: Growth mechanism, enhanced visible-light photocatalytic and photoelectrochemical performances
摘要： A novel three-dimensional (3D) Fe2O3 nanorods (NRs)/TiO2 nanosheets (NSs) heterostructure is fabricated by employing the TiO2 NSs with dominant high-energy {0 0 1} facets as synthetic template via the facile hydrothermal and chemical bath deposition methods. The structure, morphology and optical property of 3D Fe2O3/TiO2 composites are examined, and the results demonstrate that these samples have pure phase, high crystallinity and good visible-light response. Furthermore, all Fe2O3/TiO2 composites exhibit the superior photocatalytic and photoelectrochemical (PEC) performances compared to pure TiO2 NSs, which should be ascribed to the larger surface area, better optical absorption and efficient electron-hole separation of 3D Fe2O3/TiO2 heterostructure. Among Fe2O3/TiO2 composites, the sample T3 obtained by using 0.05 M iron nitrate at 90 °C for 100 min exhibited the best visible-light photocatalytic activity and PEC performance, which achieves 89.3% photodegradation of Methyl Blue within 120 min and 2.39 mA cm?2 photocurrent density at a potential of 0 V, respectively. The photocatalytic degradation efficiency and photocurrent density of T3 are 1.83 and 11.95 times higher than that of pure TiO2 NSs. In addition, the detailed growth mechanism of Fe2O3 nanomaterials onto TiO2 NSs and the optimization mechanism of photocatalytic and PEC performances are also discussed in present paper.
关键词： Photoelectrochemical,Photocatalytic,Visible-light,TiO2 nanosheets,Fe2O3/TiO2 heterostructure
更新于2025-09-23 15:22:29
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Controllable synthesis of rhombohedral α-Fe2O3 efficient for photocatalytic degradation of bisphenol A
摘要： One-step controllable synthesis of rhombohedral α-Fe2O3 photocatalyst has been successfully developed by P123 soft template assisted method. A combination analysis of XRD, BET, SEM and HRTEM has documented that P123 surfactant plays a crucial role in the controllable synthesis of rhombohedral α-Fe2O3 with the exposure of (110) and (012). The as-obtained α-Fe2O3 material is efficient for the photocatalytic degradation of Bisphenol A (BPA). About 91% of BPA (30 mg/L) was degraded by using 1 g/L α-Fe2O3 within 6 h under the simulated sunlight irradiation, which was almost twice higher than that of commercial Fe2O3. More importantly, reaction intermediates (e.g., 4, 4′-methylenediphenol, phenol and lactic acid) were confirmed by LC–MS/MS analysis, and the rational pathway of BPA degradation was finally proposed.
关键词： Bisphenol A,Photocatalysis,Rhombohedral α-Fe2O3,P123,Pathway
更新于2025-09-23 15:22:29
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Preparation of Mesoporous Fe2O3-Supported ZSM-5 Zeolites by Carbon-Templating and their Evaluation as Photo-Fenton Catalysts to Degrade Organic Pollutant
摘要： Mesoporous Fe2O3-supported ZSM-5 zeolites were prepared by carbon-templating and subsequently evaluated as photo-Fenton catalysts to degrade a dye used as a model heavy organic pollutant. The synthesis procedure of the mesoporous ZSM-5 zeolites was performed employing a nucleating gel and carbon particles as mesopores template. Thereafter, the precursor salt of the iron oxide (Fe2O3) was impregnated and then calcined to obtain the final catalyst. For comparison purposes, a conventional Fe2O3-supported ZSM-5 zeolite was also prepared. The results showed that the amount of intracrystalline mesopores formed in the ZSM-5 crystals was influenced by the amount of carbon added into the synthesis mixture. In comparison to the conventional prepared catalyst, the mesoporous Fe2O3/ZSM-5 ones showed an improved performance in the degradation of the target organic pollutant by the photo-Fenton reaction, which was attributed to the improvement of their textural properties as consequence of the mesopores generation.
关键词： Fe2O3-supported ZSM-5,Mesoporous ZSM-5,carbon template,dye degradation,photo-Fenton reaction
更新于2025-09-23 15:22:29
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Loading of alkaline hydroxide nanoparticles on the surface of Fe2O3 for the promotion of photocatalytic activity
摘要： This study focused on surface modification of iron oxide (Fe2O3) by loading alkaline oxide nanoparticles to investigate the effect of surface interactions on photocatalytic activity of this material. Fe2O3 was loaded by NaOH, KOH, and CsOH, with 0.05, 0.1, 0.4, and 1 wt% by impregnation method. The photocatalytic evaluation was carried out in a gas phase for degradation of Iso-Propyl alcohol (IPA) to acetone. The prepared samples were characterized by X-ray diffraction, UV-Visible diffuse reflectance spectroscopy, and scanning electron microscopy SEM. The photocatalytic evaluation resulted the photoactivity of Fe2O3 increases to an optimum extent by loading of alkaline hydroxides on the surface. The enhancement of photoactivity of Fe2O3 after loading can be attributed to the surface chemical reactions and transfer of photogenerated electrons from the conduction band of Fe2O3 to alkaline nanoparticles. Also, multi-electron oxygen reduction is another way supposed to facilitate the photocatalytic reaction.
关键词： CsOH,Photocatalysis,NaOH,Photodegradation,Impregnation,KOH,Fe2O3
更新于2025-09-23 15:22:29
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Hollow cage-like α-Fe <sub/>2</sub> O <sub/>3</sub> nanostructures: facile synthesis and excellent photo-Fenton catalytic performance
摘要： Herein, α-Fe2O3 hollow cage-like nanostructures were prepared via a simple in situ template-assisted hydrothermal route. The results showed that the shell and the size of the α-Fe2O3 hollow nanostructures could be easily controlled by adjusting the amount of Fe source (FeCl3). By increasing the amount of Fe source, the size increases, and the shells are built up from the dense single nanoparticle aggregations to crosslinked nanoparticle aggregations with large cavities gradually. It is found that the surface morphology has great impact on charge separation and transport of the α-Fe2O3 cage-like nanostructures, too dense particle aggregations and too many large cavities are unfavorable for electron transport, only the product with an optimal primary particles and channels could exhibit good catalytic performance in photo-Fenton degradation of rhodamine B (RhB) with visible light.
关键词： cage-like,α-Fe2O3,photo-Fenton.,hydrothermal
更新于2025-09-23 15:22:29
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Enhanced Charge Transport and Increased Active Sites on α-Fe <sub/>2</sub> O <sub/>3</sub> (110) Nanorod Surface Containing Oxygen Vacancies for Improved Solar Water Oxidation Performance
摘要： The e?ect of oxygen vacancies (VO) on α-Fe2O3 (110) facet on the performance of photoelectrochemical (PEC) water splitting is researched by both experiments and density functional theory (DFT) calculations. The experimental results manifest that the enhancement in photocurrent density by the presence of VO is related with increased charge separation and charge-transfer e?ciencies. The electrochemical analysis reveals that the sample with VO demonstrates an enhanced carrier density and reduced charge-transfer resistance. The results of DFT calculation indicate that the better charge separation is also contributed by the decrease of potential on the VO surface, which improves the hole transport from the bulk to the surface. The reduced charge-transfer resistance is owing to the greatly increased number of active sites. The current study provides important insight into the roles of VO on α-Fe2O3 photoanode, especially on its surface catalysis. The generated lesson is also helpful for the improvement of other PEC photoanode materials.
关键词： oxygen vacancies,α-Fe2O3,photoelectrochemical water splitting,charge-transfer efficiencies,density functional theory,charge separation
更新于2025-09-23 15:21:21
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Flexible and reusable cap-like thin Fe2O3 film for SERS applications
摘要： Cap-like α-Fe2O3 films are fabricated and deposited onto quartz fabric by using radio frequency magnetron sputtering and annealing. The treated fabric sample in this study shows highly sensitive surface-enhanced Raman scattering (SERS) and excellent flexibility, reproducibility and stability. In addition, the sample can be recovered after a washing process with an organic solvent and repeatedly used. The sensitive SERS performance is attributed to chemical enhancement through a charge transfer process. Moreover, the SERS performance is also found to be dependent on the light coupling effect. When the light absorbance rate of the α-Fe2O3 films increases at a wavelength near that of laser light, the film shows excellent sensitivity due to light coupling effect.
关键词： α-Fe2O3,Raman sensor,flexible,quartz fabric,SERS
更新于2025-09-23 15:21:21
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Enhanced Photoelectrochemical Performance and Stability of Si Nanowire Photocathode with Deposition of Hematite and Carbon
摘要： Tremendous efforts have been dedicated to the development of transition metal and/or metal oxide surface coating materials to enhance the activity and stability of photoelectrodes. Nanostructured Si photoelectrodes have shown outstanding photoelectrochemical (PEC) performance due to their effective photon absorption and charge generation, separation, and mobility. While the chemical stability and surface reaction efficiency of Si photoelectrodes still need improvement before commercial application. Herein, we report the design and synthesis of a composite Si photoelectrode with a configuration of C/α-Fe2O3/Si nanowires, which presented a stable photoelectrochemical hydrogen production in neutral electrolyte. The p-Si nanowires were prepared by metal-assisted chemical etching for enhanced optical absorption and decorated with a mesoporous α-Fe2O3 thin film (~80 nm) through pyrolysis of ferrocene. A thin carbon passivation layer (~20 nm) was further deposited through ion sputtering further increasing the stability of the composite structure and low bias photocurrent. The role of α-Fe2O3 and carbon layer have been discussed. The composite photoelectrode shows a stable photocurrent of ~ -27 mA/cm2 in 2 h and an anodic onset potential shift of ~0.33 V relative to the bare Si in the neutral solution.
关键词： Si nanowires,photoelectrochemistry,α-Fe2O3,carbon,hydrogen
更新于2025-09-23 15:21:21
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Visible-light degradation of sulfonamides by Z-scheme ZnO/g-C3N4 heterojunctions with amorphous Fe2O3 as electron mediator
摘要： ZnO grafted amorphous Fe2O3 matrix (ZnO/Fe2O3) was coupled with g-C3N4 to synthesize heterojunction photocatalysts with a loosened multilayered structure. The ZnO/Fe2O3/g-C3N4 exhibited enhanced photocatalytic performance in the degradation of sulfamethazine under visible-light irradiation (λ > 420 nm), with an optimum photocatalytic degradation rate approximately 3.0, 2.4 times that of pure g-C3N4 and binary ZnO/g-C3N4. Moreover, the target sulfonamides spiked in actual surface water samples could be efficiently photodegraded by ZnO/Fe2O3/g-C3N4 after 8 h of irradiation, demonstrating its practical potential. An amorphous Fe2O3-mediated Z-scheme mechanism was proposed for the charge transfer at the heterojunction surface, which involved a Fe(III)/Fe(II) oxidation-reduction center that favored the retarded charge recombination and improved photocatalytic activity. Such a mechanism was well supported by the direct detection of surface generated ·O2? and ·OH reactive species. Finally, detailed transformation pathways were proposed based on the photodegradation products identified by QToF-MS analyses. This work provides an illustrative strategy for developing efficient Z-scheme photocatalysts for water purification, by taking advantage of amorphous Fe-based oxides in the semiconductor lattice matching.
关键词： Sulfonamides degradation,Z-scheme mechanism,Electron mediator,ZnO/Fe2O3/g-C3N4,Degradation pathways
更新于2025-09-23 15:21:21
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Structural and Optical Properties of Epitaxial Iron Oxide Thin Films Deposited by Pulsed Laser Deposition
摘要： Iron oxides have been intensively studied owing to potential applications related to energy conversion and storage systems. In this paper, we investigated crystal structures and optical properties of iron oxide thin films deposited at various oxygen partial pressures and temperatures using pulsed laser deposition. The iron oxide thin films were epitaxially grown on Al2O3 (0001) substrates confirmed by X-ray diffraction measurements. With increasing the growth temperature from 450 K to 800 K, the films exhibited better crystalline hematite phase, alpha-Fe2O3. When the pressure was decreased to 0.5 mTorr, the magnetite phase, Fe3O4, was formed. We found that the optical band gaps of iron oxides mainly originated from O 2p to Fe 3d could be modulated from 2.18 eV to 2.42 eV, applicable for energy conversion systems.
关键词： Absorption,Functional devices,Pulsed laser deposition,Fe2O3,Thin films
更新于2025-09-23 15:21:01