Characterization of structural, optical and photocatalytic properties of silver modified hematite (α-FeO) nanocatalyst

Kumar, Sandeep; Kumar, Abhishek; Malhotra, Tania; Verma, Santwana

doi:10.1016/j.jallcom.2022.164006

Cited by 31 publications

(11 citation statements)

References 75 publications

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“…The bands at 226, 290, 405, 495, and 604 cm –1 represent the Fe–O bond of Hem (Figure b) . Although negligible band shifts can be observed in Cu/Co-Hem (Figure b), the increased intensity ratios between the 226 and 290 cm –1 bands in Cu-Hem and Co-Hem indicate that the doped Cu/Co also changes the Fe–O bond in Hem (Figure b). , …”

Section: Resultsmentioning

confidence: 95%

“…51 Although negligible band shifts can be observed in Cu/Co-Hem (Figure 2b), the increased intensity ratios between the 226 and 290 cm −1 bands in Cu-Hem and Co-Hem indicate that the doped Cu/Co also changes the Fe−O bond in Hem (Figure 2b). 52,53 The increased charge transfer values of the Cu/Co-doped Fh/Hem in CV analysis indicate that the doped Cu/Co promotes the current on the surface of Fh/Hem (Figure S2a,b andTable 1). Meanwhile, the obvious decreases in the corrosion potentials of the Cu/Co-doped Fh/Hem in Tafel analysis also indicate that the doped Cu/Co enhances the electron transfer rate on Fh/Hem (Figure 3a,b), thus promoting its corrosion rates.…”

Section: Acs Earth Andmentioning

confidence: 99%

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Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O₂ Solution

Tian

Zhang

et al. 2023

ACS Earth Space Chem.

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Although inorganic Fe(IV)�O oxo and Fe(III)-OOH peroxo have attracted more attention in aqueous environments, direct evidence for the characterization and identification of those oxidizing species is still lacking. In this study, the doped Cu/Co increases the reactivity of ferrihydrite/hematite in oxidizing As(III) by S(IV)-O 2 under alkaline and dark conditions. Quenching experiments exclude the contributions of •OH, O 2 •− , SO 3 •− , SO 4 •− , SO 5 •−, HSO 5 − , and H 2 O 2 and confirm that peroxo and oxo are primary oxidizing species in As(III) oxidation. Electrochemical analyses indicate that Fe(IV)�O oxo and Fe(III)-OOH peroxo are primarily located on the surface of ferrihydrite and hematite. Selective oxidation of methyl phenyl sulfoxide and methyl phenyl sulfide to the corresponding oxidation products further reveals the presence of �Fe(IV)�O oxo on both ferrihydrite and hematite, and the doped Cu/ Co significantly decreases the produced �Fe(IV)�O oxo on ferrihydrite, while increases the produced �Fe(IV)�O oxo on hematite. Meanwhile, selective oxidation of benzyl alcohol to benzaldehyde indicates the presence of �Fe(III)-OOH peroxo on both ferrihydrite and hematite, and the doped Cu/Co apparently increases the produced �Fe(III)-OOH peroxo on ferrihydrite and hematite. Raman analysis further reveals the presence of �Fe(IV)�O oxo and �Fe(III)-OOH peroxo on pure and metal-doped ferrihydrite/hematite, which also confirms that the doped Cu/Co decreases the produced �Fe(IV)�O oxo on ferrihydrite and increases �Fe(IV)�O oxo on hematite, while apparently increasing �Fe(III)-OOH peroxo on both ferrihydrite and hematite. This study enriches our understanding on the oxidizing species in the S(IV)-mediated oxidation processes under alkaline conditions, providing new insight on the oxidation reactivity of surface peroxo and oxo species mediated by the doped metal ions.

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Section: Resultsmentioning

confidence: 95%

Section: Acs Earth Andmentioning

confidence: 99%

Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O₂ Solution

Tian

Zhang

et al. 2023

ACS Earth Space Chem.

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“…In the hybrid nanomaterials, it is notable that both materials (i.e., α-Fe 2 O 3 nanoparticle and ZnO NR) exhibit diffraction peaks at specific angles (2θ) that correlate to distinct crystal planes. The XRD pattern shows the diffraction peaks at 2θ = 24.24° (012), 33.23° (104), 35.71° (110), 49.59° (024), and 54.10° (116), and planes are assigned to the crystal structure of iron oxide in hematite (α-Fe 2 O 3 ) form [ 30 , 44 ]. The presence of peaks for both materials suggests the coexistence, multiphase nature, crystalline composition, and hybrid nanostructure synthesis [ 31 ].…”

Section: Resultsmentioning

confidence: 99%

An Electroanalytical Enzymeless α-Fe2O3-ZnO Hybrid Nanostructure-Based Sensor for Sensitive Quantification of Nitrite Ions

Ahmad,

Abdullah,

Rehman

et al. 2024

Nanomaterials

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Nitrite monitoring serves as a fundamental practice for protecting public health, preserving environmental quality, ensuring food safety, maintaining industrial safety standards, and optimizing agricultural practices. Although many nitrite sensing methods have been recently developed, the quantification of nitrite remains challenging due to sensitivity and selectivity limitations. In this context, we present the fabrication of enzymeless iron oxide nanoparticle-modified zinc oxide nanorod (α-Fe2O3-ZnO NR) hybrid nanostructure-based nitrite sensor fabrication. The α-Fe2O3-ZnO NR hybrid nanostructure was synthesized using a two-step hydrothermal method and characterized in detail utilizing x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). These analyses confirm the successful synthesis of an α-Fe2O3-ZnO NR hybrid nanostructure, highlighting its morphology, purity, crystallinity, and elemental constituents. The α-Fe2O3-ZnO NR hybrid nanostructure was used to modify the SPCE (screen-printed carbon electrode) for enzymeless nitrite sensor fabrication. The voltammetric methods (i.e., cyclic voltammetry (CV) and differential pulse voltammetry (DPV)) were employed to explore the electrochemical characteristics of α-Fe2O3-ZnO NR/SPCE sensors for nitrite. Upon examination of the sensor’s electrochemical behavior across a range of nitrite concentrations (0 to 500 µM), it is evident that the α-Fe2O3-ZnO NR hybrid nanostructure shows an increased response with increasing nitrite concentration. The sensor demonstrates a linear response to nitrite concentrations up to 400 µM, a remarkable sensitivity of 18.10 µA µM−1 cm−2, and a notably low detection threshold of 0.16 µM. Furthermore, its exceptional selectivity, stability, and reproducibility make it an ideal tool for accurately measuring nitrite levels in serum, yielding reliable outcomes. This advancement heralds a significant step forward in the field of environmental monitoring, offering a potent solution for the precise assessment of nitrite pollution.

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“…Numerous synthesis approaches, including co-precipitation [26,27], auto-combustion [28][29][30], one-step ion exchange method [31], thermal oxidation [32], electrochemical method [33], gas phase flame method [34], thermal decomposition [35], electrochemical deposition [36], sol-gel method [37], the ultrasound-assisted green method [38,39], the wet chemical method [40], have been used to synthesize semiconductor iron oxide materials. Some of these methods are unfriendly to large-scale practical applications because they often require the use of costly and harmful chemicals, prolonged reaction times, demanding conditions, and high temperatures.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of hematite (α-Fe₂O₃) nanoparticles by a liquid-phase microplasma-assisted electrochemical process for photocatalytic activity

et al. 2023

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Dye contamination is becoming a more significant environmental challenge with the development of the textile industry. Scientists from all over the world are working hard to create new, more efficient ways to reduce environmental pollution through environmentally friendly synthesis techniques. In this regard, hematite (α-Fe2O3) nanoparticles have been synthesized by the novel, quick, cheap, and environmentally safe microplasma technique for the photodegradation of rhodamine-B under direct sunlight. Thus, the synthesized α-Fe2O3 nanoparticles were characterized by various characterization techniques such as X-Ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV-Vis spectroscopy). The structural and optical properties were found to vary with changing precursor concentrations. We measured the photocatalytic decolorization efficiency of synthesized hematite (α-Fe2O3) nanoparticles for rhodamine-B dye under direct sunlight. It was found that α-Fe2O3 nanoparticles exhibited a decolorization capability with 73.75% decolorization of the dye at the rate of 0.04305 g.mg-1.min-1 after 100 minutes of irradiation, exhibiting excellent performance to remove organic contaminants from wastewater.

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Characterization of structural, optical and photocatalytic properties of silver modified hematite (α-FeO) nanocatalyst

Cited by 31 publications

References 75 publications

Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O₂ Solution

Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O₂ Solution

An Electroanalytical Enzymeless α-Fe2O3-ZnO Hybrid Nanostructure-Based Sensor for Sensitive Quantification of Nitrite Ions

Synthesis of hematite (α-Fe₂O₃) nanoparticles by a liquid-phase microplasma-assisted electrochemical process for photocatalytic activity

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Characterization of structural, optical and photocatalytic properties of silver modified hematite (α-FeO) nanocatalyst

Cited by 31 publications

References 75 publications

Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O2 Solution

Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O2 Solution

An Electroanalytical Enzymeless α-Fe2O3-ZnO Hybrid Nanostructure-Based Sensor for Sensitive Quantification of Nitrite Ions

Synthesis of hematite (α-Fe2O3) nanoparticles by a liquid-phase microplasma-assisted electrochemical process for photocatalytic activity

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Product

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Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O₂ Solution

Differences in the Oxidizing Species on the Surface of Metal-Doped Ferrihydrite and Hematite in the Alkaline S(IV)-O₂ Solution

Synthesis of hematite (α-Fe₂O₃) nanoparticles by a liquid-phase microplasma-assisted electrochemical process for photocatalytic activity