Porous α-Fe2O3 Research Articles

Capacity augmentation strategy in α-Fe2O3 nanoparticles through multifaceted structural and electrochemical analyses

Hematite (α-Fe₂O₃) has garnered significant research interest for supercapacitor applications, but capacity fading and limited cyclic life remain serious challenges. In this context, the present research provides a comprehensive study of the factors that significantly impact charge kinetics within the electrode and at the solid/electrolyte interface. By integrating structural and electrochemical analyses, this study offers an effective strategy to enhance the capacity of α-Fe₂O₃ nanoparticles through rigorous scientific analysis and identification of various qualitative and quantitative factors that influence charge storage capacity. A simple one-step co-precipitation method was adopted to synthesize porous α-Fe₂O₃ nanoparticles. The quantitative analysis of charge kinetics demonstrated the domination of diffusion-controlled charge storage as the main contributor to the total charge storage. The α-Fe₂O₃ nanoparticles-based electrode delivered a high energy density of 24.6 Wh kg⁻1 at an impressive power density of 478.7 W kg⁻1. Additionally, it displayed a capacity retention of 79 % over 10,000 cycle operations. The choice of electrode material and the superior porous nanoarchitecture have proven to be advantageous for high-performance supercapacitor applications, offering fast electron/ion transport.

Porous α-Fe2O3 Hollow Rods/Reduced Graphene Oxide Composites Templated by MoO3 Nanobelts for High-Performance Supercapacitor Applications.

Porous α-Fe2O3 hollow rods/reduced graphene oxide (α-Fe2O3 HR/RGO) composites with unique morphological characteristics and a high surface area are prepared through a template strategy, which was systematically studied and found to have outstanding supercapacitive properties. When served as active material in a three-electrode setup, the optimized α-Fe2O3 HR/RGO-30, comprised 76.5 wt% α-Fe2O3 and 23.2 wt% RGO, was able to offer the largest specific capacitance of 426.3 F g-1, an excellent rate capability as well as satisfactory cycle life with capacitance retention of 87.7% and Coulombic efficiency of 98.9% after continuously charging/discharging at 10 A g-1 for beyond 10,000 cycles. Such electrochemical behaviors of the α-Fe2O3 HR/RGO-30 electrode can rival or even surpass those of many Fe2O3-based electrodes documented in the previous literature. Later, a symmetric supercapacitor cell of α-Fe2O3 HR/RGO-30//α-Fe2O3 HR/RGO-30 was fabricated. The assembled device offers the maximum energy density of 18.7 Wh kg-1, and also exhibits commendable rate capability, and features stable cycling durability (with capacitance retention of 83.2% together with a Coulombic efficiency of 99.3% after 10,000-cycle charge/discharge at 5 A g-1). These notable electrochemical performances enable the α-Fe2O3 HR/RGO-30 composite to be a high-potential material for advanced energy storage systems.

Porous double-channel α-Fe2O3/SnO2 heterostructures with multiple electronic transmission routes for the enhanced N,N-dimethylformamide gas-sensing performance

Porous double-channel α-Fe2O3/SnO2 heterostructures with multiple electronic transmission routes for the enhanced N,N-dimethylformamide gas-sensing performance

Nanostructured 3D Mesoporous α-Fe2O3 Nano-Cubes As a High-Performance Electrode for Supercapacitors

Development of energy storage devices of high energy density and long cycle life is one of the pressing needs of electronic devices. Pseudo-capacitors with iron oxide electrodes show promising energy storage devices because they are economical and safe, but have poor conductivity and stability. To achieve an improved electrochemical performance such as shorter ion-diffusion path, faster ion accessibility, and higher conductivity, a rationally design of electrode material is highly desirable. Here, we shed the light on how three-dimensional (3D) Nano porous networked α-Fe2O3 nano-cubes serves as a supercapacitor electrode. Here we show the high specific capacitance and long-life supercapacitor anode by developing a hierarchical three-dimensional α-Fe2O3 nano-cubes. KOH is used as an aqueous electrolyte. The synthesized annealed nano-cubes (PNC) have high surface areas of 5.127m2/g. The annealed Hematite (α-Fe2O3) NC show good thermodynamic stability with high reversible redox activity. The half-cell anode based on this nanostructure give rise to a high specific capacitance value of ~520F/g at a current density of 1 A/g and ~90% of the capacitance can be retained at 2 A/g after 1000 redox cycles (indicates the good cyclic stability). The present work demonstrates that binder and conductive additive-free 3D Nano porous electrodes open up a new avenue to fabricate high surface area electrodes for improved charge storage performance. These performance features are superior among those reported for iron oxide-based supercapacitors. High specific capacitance value, stable cycling, and facile preparation make Hematite NC(α-Fe2O3) an excellent material for use as supercapacitor electrodes.

Photoelectro-Fenton microreactor integrated with MOF-derived porous α-Fe2O3 film for efficient nanoplastics degradation

The stubborn Nanoplastics (NPs) have provoked serious environment pollution globally and it is urgent to develop efficient technologies to decompose them efficiently. However, the degradation efficiency is still subject to various factors such as the reactor design, catalysts, and reaction pathways. In this work, a photoelectro-Fenton microfluidic reactor was designed to enable the fine-tuning of photoelectro-Fenton reactions by applying both light irradiation and bias potentials to the reaction chamber. To enhance its degradation efficiency and reusability, a MOF-derived porous Fe2O3 material was coated in the reaction chamber. In the experiment, the voltage, illumination, flow rate, and other factors were adjusted to investigate the reactor's properties and optimize the reaction conditions. The study showed α-Fe2O3 catalytic efficiency increased with bias, reaching maximum degradation rate of large than 0.438 %/s at the bias of 1.2 V under the solar light irradiation with the light intensity of 120 mW/cm2, and did not decrease significantly in 4 repeated experiments. Furthermore, the synergistic effect of various oxidation pathways was also revealed. The photoelectro-Fenton microreactor finally showed unprecedented degradability and excellent reusability. The proposed platform is adapted to guide the AOP degradation of NPs, and has potential to be scaled up for industrial NPs removal.

Photoelectrochemical activation of peroxymonosulfate using Sn-doped α-Fe2O3 thin film for degradation of anti-inflammatory pharmaceutical drug

Introduction of oxygen vacancies (OVs) has been investigated as a promising way to improve the electrical and catalytic characteristics of a hematite (α-Fe2O3) based photoelectrode. In this work, we develop a novel method for preparing porous Sn-doped α-Fe2O3 (Sn:Fe2O3) thin films with intrinsic OVs. The procedure included spin-coating an iron precursor onto a fluorine-doped tin oxide (FTO) substrate, followed by thermal treatment at elevated temperatures. The influence of Sn dopant on the optoelectronic properties of α-Fe2O3 was demonstrated by X-ray photoelectron spectroscopy and photoelectrochemical (PEC) measurements. The combined effect of OVs and Sn doping was found to play a synergistic role in reducing the charge recombination’s. The Sn:Fe2O3 photoanodes were used as a dual catalyst to oxidise water and break down an anti-inflammatory drug called 2-(4-isobutylphenyl)propanoic acid (IBPA). The Sn:Fe2O3 thin film with a 30-minute heat treatment time displayed the highest incident photon-to-current efficiency. For the first time, Sn:Fe2O3 thin films were utilised in the effective PEC degradation of IBPA employing peroxymonosulfate (PMS) under visible light illumination. The hydroxyl radicals (OH), singlet oxygen (1O2), photogenerated holes (h+), and sulfate radicals (SO4−) were discovered to be the main reactive species during PEC degradation. IBPA degradation and the formation of new compounds were verified using liquid chromatography-mass spectrometry. The Lepidium sativum L phytotoxicity test reveals that PEC-treated wastewater with IBPA exhibits decreased toxicity.

Humidity induced resistive switching and negative differential resistance in α-Fe2O3 porous thin films

Resistive switching (RS) phenomenon at a power level on the order of nW is observed in a porous α-Fe2O3 thin film. The samples are prepared on glass substrates using spin coating with a sol-gel solution of 141.5 mM Fe(III) acetylacetonate in acetone followed by annealing at 550 °C for 75 min in air. This process produces a semi-continuous α-Fe2O3 thin film. AC I-V curves were acquired in a humidity-controlled environment, where otherwise the I-V characteristics are linear. Sweeping the voltage of the device from 0 to 10 V at the rate of 0.2 V/s with a triangular waveform, the device is in a low resistive state (LRS) from 0 to ∼4 V, at which point the current sharply decreases from ∼4–10 V, which is the signature of a negative differential resistance (NDR). Sweeping back from 10 to 0 V, the device remains in a high resistive state (HRS). The I-V curves are symmetric and highly reproducible, exhibiting the RS and NDR phenomena in the negative bias. A ratio of HRS/LRS > 12 at 2 V bias was achieved in both positive and negative bias regions. The RS and symmetric NDR behavior of the device is attributed to the trapping and de-trapping of the carriers at the space charge region formed by the movement of ions from water molecule dissociation towards respective electrode/material interface.

Role of oxygen vacancies and porosity in enhancing the electrochemical properties of Microwave synthesized hematite (α-Fe2O3) nanostructures for supercapacitor application

Herein, we report a green and cost-effective microwave-assisted synthesis of oxygen vacancy-rich porous α-Fe2O3 nanorods and α-Fe2O3 nanospheres for supercapacitor applications. The synthesized samples were characterized using Field emission scanning electron microscopy (FESEM) coupled with Energy Dispersive X-Ray (EDX), X-ray diffraction (XRD), Raman Spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analysis. The synthesized α-Fe2O3 nanorods have a high specific surface area of 133.6 m2g-1 and a pore size of around 15.2 nm. With the use of cyclic voltammetry (CV), galvanostatic charge-discharge experiments, and electrochemical impedance spectroscopy, the electrochemical characteristics of α-Fe2O3 nanorod and nanosphere-based electrodes were studied and compared. In contrast to hematite nanospheres, which displayed a specific capacitance of only 715.05 Fg-1, hematite nanorods exhibited the highest specific capacitance of 1253.02 Fg-1 and excellent capacitance retention of 93% after a long life of 3000 cycles in 3 M KOH electrolyte with a potential window of −0.2 to 0.55 V. The enhancement in electrochemical properties could be attributed to its porous nature and the presence of oxygen vacancies which provided more active sites for redox reactions and high electrical conductivity. The results demonstrate that oxygen vacancy-rich and porous α-Fe2O3 nanorods synthesized via the green approach can serve as an ideal electrode material for supercapacitors.

The preparation of rod-like porous α-Fe2O3 with large interplanar spacing for symmetric supercapacitors

Rod-like porous α-Fe2O3 was synthesized by static hydrothermal treatment at 160°C and used as a symmetric supercapacitor. The phase information, structure, morphology, valence state and composition of the prepared sample were characterized using X-ray diffraction, infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption. The results show that the prepared α-Fe2O3 is a rod-like porous material dominated by mesopores. Moreover, the α-Fe2O3 is a hexagonal single crystal with [FeO6] octahedrons and the interplanar crystal spacings are large enough for electrolyte ion diffusion. In both KOH and Na2SO4 electrolytes, the α-Fe2O3 sample displays good pseudocapacitance performance. However, the specific discharge capacity and energy density in KOH are larger than in Na2SO4. In 1 mol L–1 of KOH, remarkable capacities of 139 and 35.5 F g–1 are obtained and an energy density of 3.91 and 1.01 Wh kg–1 is achieved at 1 and 20 A g–1 respectively. After 10 000 cycles, 87.7% of the specific capacitance is still retained at 1 A g–1. The good capacitance properties may attributed to the rod-like porous structure and large interplanar spacing, which provide good ion insertion–exit paths, enough oxidation–reduction active sites and a fast ion transfer velocity.

Monoclinic-rich CsPbBr3/α-Fe2O3 S-scheme heterojunction for highly efficient thermal-assisted CO2 photoreduction

A new monoclinic-rich CsPbBr3/porous α-Fe2O3 with 3D/3D heterojunction has been prepared by a facile one-step ligand-assisted reprecipitation (LARP) under low temperature and air atmosphere. The morphologies (i.e., cubic and monoclinic phases) of CsPbBr3 are easily tuned by varying the ratios of precursor solution during the LARP process. We observed that monoclinic-rich CsPbBr3 is favorable to the photocatalytic reduction of CO2 with the superior electron consumption rate of 1.42 mmol g−1 h−1. Upon the heterojunction of monoclinic-rich CsPbBr3 with porous α-Fe2O3, the electron consumption rate is further enhanced to 3.38 mmol g−1 h−1, which is ca. 2.4-fold improvements of pristine monoclinic-rich CsPbBr3. More importantly, the activity can maintain ca. 90% after three consecutive cycles of photocatalytic CO2 reduction. The surpassing performance could be attributed to the higher CO2 uptakes, superior charge separation properties of the CsPbBr3/α-Fe2O3 heterojunction. The apparent activation energies of CO and H2 production calculated by the Arrhenius equation are 26.67 and 31.95 kJ mol−1, respectively. Time-resolved photoluminescence and ultraviolet photoelectron spectroscopy were used to evidence that the S-scheme pathway with an interfacial charge transfer constant of 2.53 × 108 s−1 occurs at the interface of monoclinic-rich CsPbBr3/porous α-Fe2O3. This study demonstrates a very simple wet-chemistry route to synthesize efficient morphology-dependent perovskite/α-Fe2O3 heterojunctions with 3D/3D construction which may provide the promising applications in the solar conversions of CO2.

Activating C-H Bonds by Tuning Fe Sites and an Interfacial Effect for Enhanced Methanol Oxidation.

The interaction mechanism between the reacting species and the active site of α-Fe2 O3 -based photoanodes in photoelectrochemical methanol conversion reaction is still ambiguous. Herein, a simple two-step strategy is demonstrated to fabricate a porous α-Fe2 O3 /CoFe2 O4 heterojunction for the methanol conversion reaction. The influence of the electronic structure of active site and interfacial effect on the reaction are investigated by constructing two different FeO6 octahedral configurations and heterogeneous structures. The optimal sample ZnFeCo-2 affords high photocurrent density of 1.17 mA cm-2 at 0.5 V vs Ag/AgCl, which is 3.2 times than that of ZnFe (0.37 mA cm-2 ). Meanwhile, the ZnFeCo-2 also exhibits 97.8% Faraday efficiency of CH3 OH to HCHO, and long-term stability over 40 h. Furthermore, density functional theory calculations reveal that the heterostructured α-Fe2 O3 /CoFe2 O4 with favorable electron transfer effectively lowers methanol adsorption, C-H bond activation, and HCHO desorption energy relative to the pristine α-Fe2 O3 , resulting in excellent methanol conversion efficiency.

The excellent photocatalytic overall water splitting activity of TpPa-1-COF excited via MOF derived FeP-PC and α-Fe2O3 dual cocatalysts

Covalent organic frameworks (COFs) as an emerging porous material have exhibited excellent application prospects in the field of photocatalysis. Nevertheless, the overall water splitting using solar energy by COF-based photocatalysts remains a huge challenge due to the rapid charge recombination and insufficient redox catalytic capacity. Herein, for the first time, the novel Fe-MOF-derived α-Fe2O3 and FeP-PC was designed and adopted as dual co-catalysts to facilitate the separation and utilization efficiency of charge carriers and activate the overall water splitting performance of the ketoenamine based TpPa-1-COF, with both the porous α-Fe2O3 and FeP-PC acting as the framework supporting to effectively prevent the agglomeration of TpPa-1-COF during the fabrication and photocatalytic process. Meanwhile, the construction of Z-scheme heterostructures and the connection of covalent bonds in the interface of α-Fe2O3/TpPa-1-COF/FeP-PC effectively facilitate the separation and transport of charge. Consequently, the optimal α-Fe2O3/TpPa-1-COF/FeP-PC excites very competitive photocatalytic overall water splitting performance.

Dynamic Adsorption of As(V) onto the Porous α-Fe2O3/Fe3O4/C Composite Prepared with Bamboo Bio-Template

Arsenic (As(V)), a highly toxic metalloid, is known to contaminate wastewater and groundwater and is difficult to degrade in nature. However, the development of highly efficient adsorbents, at a low cost for use in practical applications, remains highly challenging. Thus, to investigate the As(V) adsorption mechanism, a novel porous α-Fe2O3/Fe3O4/C composite (PC-Fe/C-B) was prepared, using bamboo side shoots as a bio-template, and the breakthrough performance of the PC-Fe/C-B composite-packed fixed-bed column in As(V) removal was evaluated, using simulated wastewater. The PC-Fe/C-B material accurately retained the hierarchical porous microstructure of the bamboo bio-templates, and the results demonstrated the great potential of PC-Fe/C-B composite, as an effective adsorbent for removing As(V) from wastewater, under the optimal experimental conditions of: influent flow 5.136 mL/min, pH 3, As(V) concentration 20 mg/L, adsorbent particle size < 0.149 mm, adsorption temperature 35 °C, PC-Fe/C-B dose 0.5 g, and breakthrough time 50 min (184 BV), with qe,exp of 21.0 mg/g in the fixed-bed-column system. The CD-MUSIC model was effectively coupled with the transport model, using PHREEQC software, to simulate the reactive transportation of As(V) in the fixed-bed column and to predict the breakthrough curve for column adsorption.

Optimizing treatment of alcohol vinasse using a combination of advanced oxidation with porous α-Fe2O3 nanoparticles and coagulation-flocculation

This study utilizes a novel method, namely the combination of advanced oxidation processes with synthesized highly porous α-Fe2O3 nanoparticles and coagulation-flocculation with polyacrylamide, to investigate the effects on COD removal in alcohol vinasse. Highly porous α-Fe2O3 nanoparticles were prepared via a chemical precipitation technique. The characteristic of the synthesized α-Fe2O3 nanoparticles were determined by FT-IR, Raman spectroscopy, XRD, SEM, and N2 adsorption-desorption isotherms. The effect of different α-Fe2O3 nanoparticles loading for chemical oxygen demand (COD) removal efficiency was investigated. The results revealed that at α-Fe2O3 nanoparticle dose of 3000 ppm had the highest COD removal for vinasse. Then, central composite design (CCD) was used to optimize the operating variables such as pH, time, oxidant dosage, and coagulant dosage, and their optimum values were determined to be pH:7.36, 90 min, 17.89 wt% oxidant dosage, and 1.6 wt% coagulant dosage, to achieve a high COD removal efficiency in 70 ℃ for alcohol vinasse (98.64%). Based on optimal conditions, the porous α-Fe2O3 nanoparticles possess superior catalytic activity in the advanced oxidation process compared to other treating methods. Also, the mechanism of the catalytic oxidation reaction is evaluated.

Carbon-doped porous hollow alpha-Fe2O3 microtubules controlled by absorbent cotton bio-template to detect acetic acid vapor

To overcome the scarcity and costliness of noble metal dopants, carbon (C) doping, as a low-cost alternative, was achieved by absorbent cotton when the alpha (α)-Fe2O3 microtubules were synthesized with a facile hydrothermal method and necessary calcination. The absorbent cotton not only provided carbon source but controlled the microtubular morphology of α-Fe2O3. Meanwhile, for comparison, a pure α-Fe2O3 nanoparticles sample was also prepared without using absorbent cotton. Numerous techniques were employed to characterize the element composition and microstructures. The consequences demonstrated that carbon had been successfully incorporated into the porous hollow α-Fe2O3 microtubules composed of many nanoparticles. Compared with the α-Fe2O3 nanoparticles, the carbon-doped α-Fe2O3 microtubules possessed the unique morphology, large specific surface area and pore size, and abundant oxygen vacancies (OV). To reveal the function of the carbon-doped α-Fe2O3 microtubules and α-Fe2O3 nanoparticles, two chemical gas sensors were manufactured and researched systematically. Forasmuch as those advantages mentioned above, the sensor based on the carbon-doped α-Fe2O3 microtubules exhibited better gas sensing properties to acetic acid vapor at a lower optimal operating temperature of 260 °C, such as higher response value, shorter response and recovery time, good repeatability, and stability. And thence the carbon-doped α-Fe2O3 microtubules product could be considered as an excellent acetic acid vapor sensor in the future. In addition, the possible grown mechanism and gas sensing mechanism of the carbon-doped α-Fe2O3 microtubules were discussed in detail. The work provides a new strategy to improve the gas sensing performance of α-Fe2O3 material.

Green synthesis of MIL-100(Fe) derivatives and revealing their structure-activity relationship for 2,4-dichlorophenol photodegradation

MIL-100(Fe), a kind of iron-based metal-organic framework materials (MOFs), can be synthesized at room temperature or hydrothermal conditions, which are promising precursor materials for preparing photocatalysts to degrade some recalcitrant chlorophenols in industrial wastewater. However, the relationship between the structural characterization of MIL-100(Fe) derivatives and their photodegradation behavior of chlorophenol pollutants is still unclear. Thus, in this work, a porous Z-scheme α-Fe2O3/MIL-100(Fe) composite was successfully fabricated via partial-pyrolysis of MIL-100(Fe) precursor synthesized through green synthesis route, which was further used for degrading high-concentration of 2,4-dichlorophenol under visible-light illumination (λ > 420 nm). The effects of synthesis route and pyrolysis temperature of MIL-100(Fe) on the degradation efficiencies of as-derived materials for 2,4-dichlorophenol were investigated. The structure-activity relationship was illuminated in detail. Otherwise, the influence of several process factors, i.e., initial concentration and pH of the 2,4-dichlorophenol solution, catalyst dosage on the degradation efficiency of 2,4-dichlorophenol has also been performed. The removal efficiency of 2,4-dichlorophenol with the initial concentration of 100 mg L−1 reached up to 87.65% under optimized conditions. Lastly, the possible mechanism was explored based on trapping experiments and some other characterization results. The study in this paper not only exhibited new insight into the modified α-Fe2O3 material with high photocatalytic activity but also provided a promising method for treating wastewater containing 2,4-dichlorophenol or other similar organic pollutants.

Porous α-Fe2O3 gas sensor with instantaneous attenuated response toward triethylamine and its reaction kinetics

To achieve highly selective and rapid detection of triethylamine (TEA) at a relatively low temperature remains challenging. In this work, we report an ultrasensitive TEA gas sensor with a specific response based on the porous α-Fe2O3 hollow sphere array, which shell is composed of fusiform particles. At a low operating temperature (160 °C), the sensor shows high response (75.8) toward 10 ppm TEA with a short response time (2 s) and can detect TEA as low as 50 ppb. More importantly, an obvious attenuation characteristic is observed during TEA detection. This distinctive response toward TEA gas is repeatable when the operating temperature is over a threshold (>120 °C). Moreover, the instantaneous attenuated response is found to be independent of the gas concentration and humidity but much related to specific gases, demonstrating its potential to be used as a characteristic signal to achieve highly selective detection of TEA molecules. Furthermore, based on density functional theory (DFT) calculations, the attenuated response can be ascribed to a special surface dynamic reaction process involving the thermal decomposition of TEA molecules and the formation of nitrogen oxides, which is verified by the quasi in-situ X-ray photoelectron spectroscopy analysis. This work will provide a new idea for developing highly selective and sensitive sensors.

Porous α-Fe2O3 nanofiber combined with carbon nanotube as anode to enhance the bioelectricity generation for microbial fuel cell

Microbial fuel cell (MFC) is a potential technology for bioelectricity generation from waste. Unfortunately, it is still a challenge for practical application due to the low power density. Immense efforts have been extended to boost the design of bioanode, mainly including the improvement on bacterial adhesion and extracellular electron transfer (EET) between bacteria and anode. Herein, electrospun porous α-Fe2O3 nanofibers integrated with carbon nanotubes (CNTs) are developed for MFC. Benefiting from the good electricity, ultrahigh porosity and three-dimensional interpenetrated network of fabricated CNTs/α-Fe2O3, the decorated anode is capable of enriching active bacteria and promoting effective EET rate. Consequently, the MFC based on CNTs/α-Fe2O3 nanofibers as anode achieves the eminent power density of 1959 mW/m2 and high COD removal efficiency of 85.04%, superior to that of α-Fe2O3 anode (940 mW/m2; 81.66%) and bulk carbon cloth anode (432 mW/m2; 65.83%). More importantly, the CNTs/α-Fe2O3 modified anode is favorable for electrogenic active bacteria attachment, thus improving the bioelectricity performance. The consequence suggests that this strategy can offer a potential application in power production and pollutant removal.

Facile synthesis of porous waist drum-like α-Fe2O3 nanocrystals as electrode materials for supercapacitor application

Facile synthesis of porous waist drum-like α-Fe2O3 nanocrystals as electrode materials for supercapacitor application

Improved photocatalytic activities of recyclable porous Fe2O3 nanotubes by modifying with nano-sized SiO2 and g-C3N4 for degrading 2-chlorophenol

It is highly desired to fabricate efficient α-Fe2O3-based photocatalysts with recyclable feature for pollutants degradation. Herein, porous α-Fe2O3 nanotubes with high photocatalytic activity for degrading 2-chlorophenol (2-CP) have been successfully synthesized by a phase separation electrospinning process, with a pipe diameter of about 200 nm . The photoactivity is greatly improved by in-situ introducing SiO2, attributed to the increased surface area by decreasing the size of nanoparticles shell from ~ 30 to 15 nm. Furthermore, the photoactivity of SiO2 modified α-Fe2O3 is further improved by coupling with porous g-C3N4 nanosheets, ascribed to the promoted charge separation by the newly accepted S-scheme charge transfer mainly based on the EPR tests and photocurrent action spectra. Interestingly, the optimized α-Fe2O3-based nanotubes exhibit ~ 4-time improvement of the kinetic rate constant in 2-CP degradation compared with the reported α-Fe2O3 nanoparticles, with good recyclability by self-sediment.