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A high-performance room temperature methanol gas sensor based on alpha-iron oxide/polyaniline/PbS quantum dots nanofilm
摘要： A high-performance room temperature methanol gas sensor based on alpha-iron oxide/polyaniline/lead sulfide quantum dots (α-Fe2O3/PANI/PbS QDs) nanofilm was demonstrated in this paper, among which the α-Fe2O3 was an urchin-shaped hollow microsphere. The sensing film was fabricated on an epoxy substrate with interdigital electrodes via successive ionic layer adsorption and reaction technique. The prepared α-Fe2O3/PANI/PbS QDs nanocomposite was examined by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, scanning election microscopy and Fourier transform infrared spectrum. The methanol sensing performances of the α-Fe2O3/PANI/PbS QDs film sensor were investigated against methanol from 10 to 100 ppm at room temperature. The experimental results indicated that the methanol sensor in this work had an excellent response, outstanding selectivity and good repeatability at room temperature. The underlying sensing mechanism of the α-Fe2O3/PANI/PbS QDs film toward methanol was ascribed to a series of interactions and changes on the surface of thin films, which make their resistance change greatly. Larger surface area and much more active adsorption sites also played an important role.
关键词： Methanol gas sensor,Room temperature,Successive ionic layer adsorption and reaction,Hydrothermal method,α-Fe2O3/PANI/PbS QDs
更新于2025-11-14 17:15:25
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α-Fe <sub/>2</sub> O <sub/>3</sub> Polyhedral Nanoparticles Enclosed by Different Crystal Facets: Tunable Synthesis, Formation Mechanism Analysis, and Facets-dependent <i>n</i> -Butanol Sensing Properties
摘要： Three kinds of polyhedral α-Fe2O3 nanoparticles enclosed by different facets including oblique parallel hexahedrons (op-hexahedral NPs), cracked oblique parallel hexahedrons (cop-hexahedral NPs), and octadecahedral nanoparticles (octadecahedral NPs), were successfully prepared by simply changing only one reaction parameter in the hydrothermal process. The structural and morphological of the products were systematically studied using various characterizations including X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), revealing that the three kinds of α-Fe2O3 nanoparticles were enclosed by {104}, {110}/{104}, and {102}/{012}/{104} crystal planes, respectively. The exposed facets and shape of the nanocrystals were found to be affected by the adding amount of ethylene glycol in the solvent. The gas-sensing properties and mechanism of the α-Fe2O3 samples were studied and analyzed, which indicated that the sensitivity of the three samples followed the order of octadecahedral NPs (cid:2) cop-hexahedral NPs (cid:2) op-hexahedral NPs due to the combined effects of specific surface area and oxygen defects in the nanocrystals.
关键词： Polyhedron,n-Butanol,Hydrothermal synthesis,α-Fe2O3 nanoparticles,Gas-sensing
更新于2025-11-14 17:03:37
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Rationally Designed Fe2O3/GO/WO3 Z-Scheme Photocatalyst for Enhanced Solar light Photocatalytic Water Remediation
摘要： A novel ternary Fe2O3/GO/WO3 all-solid-state Z-Scheme photocatalyst was rationally designed. Structural, morphological, optical and electronic properties of the synthesized nanocomposite were investigated by XRD, SEM, TEM, UV-vis Diffuse Reflectance and Raman spectroscopy. The results revealed the successful synthesis of the nanocomposite materials. Uniquely, double absorption edges at 2.0 and 2.3 eV for Fe2O3/WO3 and triple absorption edges at 1.5, 1.8 and 2.1 eV for Fe2O3/GO/WO3 were investigated for the first time. Lower absorption band edges dominated for both Fe2O3/WO3 and Fe2O3/GO/WO3, while higher absorption edges dominated for pure nanomaterials. The enhanced interaction among GO, Fe2O3 and WO3 matrix explained the reduction in the CB energy leading to efficient electron separation and transformation and consequently improving the photocatalytic activity. The visible light photocatalytic performance of Fe2O3/GO/WO3 nanocomposites were evaluated for degradation of methylene blue (MB) and crystal violet (CV) dyes as model water pollutants. The photocatalytic activity for degradation of both dyes was found to be greatly enhanced in the presence of ternary Fe2O3/GO/WO3 nanocomposite as compared to nanocomposite systems of Fe2O3/WO3, WO3/GO and Fe2O3/GO or pure Fe2O3 and WO3 nanomaterials. The enhancement in the photocatalytic performance of ternary Fe2O3/GO/WO3 nanocomposite was proven to be due to the all-solid-state Z-Scheme in which the photogenerated electrons in the CB of photosystem I (WO3) transferred through GO mediator and recombined with the photogenerated holes in the VB of Fe2O3 (photosystem II). So that, the electron-hole pair recombination can be suppressed in both systems. Moreover, the photocatalytic activity of the best Fe2O3/GO/WO3 nanocomposite (FGW 30) has been tested for the degradation of phenol. The results show that 95.4 % of phenol was degraded in 120 minutes. Thus, this study provides an efficient green Z-Scheme photocatalyst for water remediation utilizing solar light.
关键词： solar light photocatalysis,organic dyes degradation,all-solid-state Z-Scheme,Ternary Fe2O3/GO/WO3,phenol mineralization
更新于2025-11-14 15:26:12
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Synthesis of novel Mn-doped Fe2O3 nanocube supported g-C3N4 photocatalyst for overall visible-light driven water splitting
摘要： A novel Mn-doped Fe2O3 modified g-C3N4 nanosheets composite has been prepared for overall water splitting. Structure characterizations reveal that the Mn are successfully doped in the Fe2O3 nanoparticle and a close interface between g-C3N4 and Mn-doped Fe2O3is obtained. The optimized FMC-10 photocatalyst has a H2 evolution of 51 μmol h?1. The improved photocatalytic performance can be ascribed to the synergy effect of both Mn-doped Fe2O3and g-C3N4. Doping Fe2O3 with Mn promotes photo-induced charges and increases the charge transfer for the improved conductivity of the bulk Fe2O3, while favorable contacting with g-C3N4 enhances the charge separation ability.
关键词： Mn doped,Pure water splitting,g-C3N4,Fe2O3
更新于2025-11-14 15:15:56
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Adsorption and photodegradation efficiency of TiO2/Fe2O3/PAC and TiO2/Fe2O3/zeolite nanophotocatalysts for the removal of cyanide
摘要： The synthesized TiO2/Fe2O3 nanostructures supported on powder activated carbon (PAC) and zeolite at different mole ratios of Fe3+/TiO2 were characterized by XRD, XRF, FESEM, EDX, TEM, FTIR, BET and, PL analyses and their cyanide photodegradation mechanism was thoroughly discussed. The results confirmed not only TiO2/Fe2O3/PAC had higher photocatalytic and adsorption capability but also better structural stability and reusability for cyanide removal than TiO2/Fe2O3/zeolite. The first order kinetics model indicated that the photodegradation rate using TiO2/Fe2O3/PAC was 1.3 times higher than that of TiO2/Fe2O3/zeolite. The response surface methodology (RSM) assessment showed that pH, irradiation time and initial cyanide concentration using UV/H2O2/TiO2/Fe2O3/zeolite system had more effects on the degradation respectively; whereas the effectiveness of UV/H2O2/TiO2/Fe2O3/PAC process was highly influenced by initial cyanide concentration than the other two parameters. High R2 and well-fitted residual plots approved the accuracy of the models in predicting the cyanide degradation efficiency using both the photocatalysts.
关键词： and adsorption comparison,Cyanide,Response surface methodology (RSM),TiO2/Fe2O3/zeolite and TiO2/Fe2O3/PAC photocatalysts,Photodegradation,Kinetic
更新于2025-09-23 15:23:52
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The efficiency and mechanism in a novel electro-Fenton process assisted by anodic photocatalysis on advanced treatment of coal gasification wastewater
摘要： A novel dual-chamber photo-electrochemical oxidation system with Fe@Fe2O3/CF cathode was constructed by combining cathodic electro-Fenton and anodic photocatalysis for advanced treatment of biologically pretreated coal gasification wastewater (CGW). In the electro-Fenton cathode chamber, maximal chemical oxygen demand (COD) removal efficiency of 84.2% was arrived within 120 min at current density 10 mA/cm2, initial pH 3 and air flow rate 0.4 L/min for its initial concentration of 200 mg/L. Correspondingly, the effluent concentration of COD, BOD5, TOC and total phenols were 31.5, 3.9, 8.4 and 13.8 mg/L respectively, satisfying the stringent wastewater discharge standard. Moreover, the H2O2 concentration change and wastewater acute toxicity were analyzed. Furthermore, a reasonable degradation mechanism was proposed based on the contribution of hydroxyl radicals (%OH), and thus degradation pathway of phenol as typical pollutant was also speculated. The integrated system is confirmed to be high-effective and stable, and thus it is a potentially promising alternative for treatment toxic refractory industrial wastewater.
关键词： COD removal,Hydroxyl radical,Electro-Fenton,Fe@Fe2O3/CF,Coal gasification wastewater
更新于2025-09-23 15:23:52
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A novel P-doped Fe2O3-TiO2 mixed oxide: Synthesis, characterization and photocatalytic activity under visible radiation
摘要： In this work, a novel P-doped Fe2O3-TiO2 mixed oxide was successfully prepared by a microwave assisted sol-gel method. The synthesized catalyst was characterized by N2 physisorption, SEM, XRD, XPS, and FTIR, UV–vis DRS, and PL spectroscopies. The iron and phosphorus content in the catalyst samples were quanti?ed by AAS and ICP-OES, respectively. The photocatalytic activity of P-doped Fe2O3-TiO2 powders were evaluated in the photocatalytic degradation of sulfamethazine (SMTZ). The Box Behnken design (BBD) and response surface methodology (RSM) were applied for modeling the e?ect and optimizing of the operational parameters levels on the degradation percentage of SMTZ. The complete degradation and mineralization percentage of 30% of SMTZ solution at pH 9 was achieved within 300 min of reaction, with the optimum P doping amount of 1.2 wt % and 1.25 g/L of catalyst loading. The 1.2 wt % P-doped Fe2O3-TiO2 mixed oxide showed considerably higher photocatalytic activity than Fe2O3-TiO2 or TiO2. This enhanced performance could be attributed to the small crystallite size, narrow band gap, high speci?c surface area and increased number of surface hydroxyls on TiO2 nanoparticles. Additionally, the stability and reusability of this catalyst was demonstrated during three cycles of SMTZ degradation.
关键词： Enhanced surface area,Visible light activation,Box behnken design,Reusability,P-doped Fe2O3-TiO2 mixed oxide
更新于2025-09-23 15:23:52
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One-Step Solvothermal Formation of Pt Nanoparticles Decorated Pt <sup>2+</sup> -Doped α-Fe <sub/>2</sub> O <sub/>3</sub> Nanoplates with Enhanced Photocatalytic O <sub/>2</sub> Evolution
摘要： The photooxidation of water into O2 has been identified as the barrier of water-splitting, and light-driven water oxidation catalysts have been intensively explored to develop highly active water splitting materials. Despite the fascinating advantages for photocatalytic water oxidation, such as abundance in nature, inexpensiveness, low toxicity, thermo/photo-stability, and suitable electronic band structures, hematite α-Fe2O3 is a poor photocatalyst for water oxidation due to its short exciton lifetime and hole diffusion length, weak carrier mobility and shallow sunlight penetration depth. In this work, we have synthesized Pt nanoparticles decorated Pt2+-doped α-Fe2O3 nanoplates (Pt/Pt-Fe2O3 NPs) by a one-step solvothermal route, which exhibit the enhanced photoactivity and photostablity for water oxidation. The introduction of the Pt into the α-Fe2O3 by the means of elemental doping and nanoparticle decoration accounts for the enhanced performance. The doping of Pt2+ into α-Fe2O3 improves the isolation efficiency of the photo-induced carriers which remarkably increases the lifespan of hole carriers, and the adherence of metal Pt nanoparticles to the surface of α-Fe2O3 leads to formation of schottky barriers at the interface which effectively impedes the combination of photo-generated electrons and holes.
关键词： photocatalytic O2 evolution,Pt nanoparticles decoration,Pt2+ doping,schottky barrier,α-Fe2O3 nanoplates
更新于2025-09-23 15:23:52
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Elucidation of the structural and charge separation properties of titanium-doped hematite films deposited by electrospray method for photoelectrochemical water oxidation
摘要： Elemental doping is considered to be an effective strategy to improve the photoelectrochemical (PEC) activity of hematite (a-Fe2O3) as a photoanode for water splitting, but the precise function(s) of the dopant remains unclear. In this study, we report on the structural and charge separation properties of titanium-doped hematite (Ti doped Fe2O3) films prepared by a simple electrospray technique for PEC water oxidation. The effect of Ti doping on the structure, morphology, light absorption, and electrical and photoelectrochemical properties was investigated on a-Fe2O3 films. SEM images revealed a reduction in particle sizes for 2% Ti doped a-Fe2O3, while an increase in particle size was observed for higher Ti content. XRD confirmed the presence of a-Fe2O3 without any impurity or other phases. From XPS spectra, the incorporation of Ti was confirmed in the form of Ti4+ as predominant species while no impurities from the substrate were detected. When the Ti doped Fe2O3 (2% Ti) film was used as a photoanode in a PEC cell, it delivered the best performance with a maximum photocurrent density of 1.09 mA cm-2 (at 1.8 V vs. RHE and under standard 1 sun illumination conditions (AM 1.5 G, 100 mW cm-2)), which is 2 times higher than that of the un-doped a-Fe2O3 (0.51 mA cm-2). The photoelectrode also showed a superior incident photon to current efficiency (IPCE) as compared to an un-doped a-Fe2O3. This enhancement in performance was attributed to the better charge separation and transport properties of a-Fe2O3 due to Ti doping, as revealed by an electrochemical impedance spectroscopy (EIS) analysis.
关键词： Electrospray deposition,PEC,a-Fe2O3,Ti doping,Water splitting
更新于2025-09-23 15:23:52
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Heterogeneous degradation of organic contaminants in the photo-Fenton reaction employing pure cubic β-Fe2O3
摘要： Pure cubic β-Fe2O3 crystal, which can absorb visible light (< 650 nm) on account of the bandgap of 1.9 eV as a direct bandgap semiconductor, was employed as a low-cost and non-toxic catalyst for photo-Fenton reaction in this article. Diverse organic contaminants including rhodamine B (RhB), methyl orange (MO), alizarin red (AR) and phenol can be effectively degraded. In particular, the degradation of RhB were investigated detailedly. As such, hydroxyl radicals (%OH) were verified to act as considerable active species for the process by using terephthalic acid as an indicator. Degradation mechanism and intermediates of phenol in the photo-Fenton reaction was discovered by virtue of liquid chromatography-mass spectrometry (LCeMS). Notably, hydroxylation of phenol generated some intermediates, which are converted into H2O and CO2 eventually.
关键词： Photo-Fenton,H2O2,β-Fe2O3,Degradation,Hydroxyl radicals
更新于2025-09-23 15:22:29