Novel microwave-assisted synthesis of leaf-like MnMoO4 nanostructures and investigation of their photocatalytic performance

Namvar, Farzad; Beshkar, Farshad; Salavati‐Niasari, Masoud

doi:10.1007/s10854-017-6499-0

Cited by 25 publications

(7 citation statements)

References 23 publications

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“…X-ray diffraction (XRD) patterns were then used to present the phase component of the catalysts. As illustrated in Figure a, the diffraction peaks of the neat Mn- or Mo-based oxide were in good accordance with the standard patterns of Mn 2 O 3 (JCPDS-71-0636) at 23.1, 32.9, 38.2, 45.1, 49.3, 55.1, and 65.7° corresponding to the (211), (222), (400), (332), (431), and (440) crystal planes and those of MoO 3 (JCPDS-99-0080) at 12.8, 23.3, 25.9, 27.3, 33.7, 40.0, 49.2, and 58.8° corresponding to the (020), (110), (120), (111), (150), (002), and (081) crystal planes, respectively. , When the Mn/Mo ratio was 1/1, the diffractions of MnMoO 4 (JCPDS-72-0285) at 22.7, 25.8, 26.7, 31.3, 33.0, 42.5, 46.4, and 51.2° were detected, which were attributed to the (021), (220), (−112), (112), (−222), (−241), (042), and (−204) crystal planes, respectively. − At the Mn/Mo ratios of 1/2, the emergence of diffraction peaks was attributed to MoO 3 , while MnO 2 (JCPDS-24-0735) and Mn 2 O 3 phases were detected when Mn was in excess. Notably, the peak intensities corresponding to MnO 2 at 37.3, 56.6, 64.8, and 72.2° corresponding to the (101), (211), (002), and (301) crystal planes increased with the increases in Mn/Mo ratios, indicating the generation of Mn species with higher oxidation states.…”

Section: Resultssupporting

confidence: 76%

Engineering the Electronic Structure of Mo Sites in Mn–Mo–O Mixed-Metal Oxides for Efficient Aerobic Oxidative Desulfurization

et al. 2021

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Aerobic oxidative desulfurization (AODS) is a vital development aspect for the deep desulfurization of fuel, which requires catalysts with high performance to efficiently convert thiophenic sulfides to sulfones. Here, we demonstrate that Mo sites in Mn−Mo−O mixed-metal oxides (MMOs) can serve as a robust and stable catalyst for the AODS with oxygen contained in atmospheric air as a sustainable oxidant. By systematically studying the effect of the Mn/Mo ratio on the phase, the electronic structure, and the catalytic activity of the MMOs, we reveal that the Mn species could contribute to the partial reduction of Mo species by donating electrons and thereby cause considerable surface defects, further giving our catalyst an improved catalytic performance with a higher turnover frequency value (TOF) compared to the reported MMOs. We show that the optimal catalyst with a Mn/Mo ratio of 4/1 could achieve complete aerobic conversion of dibenzothiophene (DBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) under mild conditions of 100 °C and atmospheric pressure in 4 h with the TOF value of 4.43 h −1 . Finally, the catalyst can be used repeatedly six times without structural change and performance attenuation.

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Section: Resultssupporting

confidence: 76%

Engineering the Electronic Structure of Mo Sites in Mn–Mo–O Mixed-Metal Oxides for Efficient Aerobic Oxidative Desulfurization

et al. 2021

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“…Concerning the synthetic routes, there are many reports on the preparation of MnMoO 4 . These materials have been produced by the solid-state ceramic route, , combustion synthesis, precipitation, sonochemical, ,, microemulsion-based method, , ultralow temperature, solvent-free microwave, and hydrothermal technology. ,,,− In this respect, the hydrothermal technology appears as the most powerful synthesis methodology to produce single-phase, crystalline materials . This technology make use of solubilization/precipitation phenomena shared with redox and acid–base chemistry, which allow the assessment to new hybrid inorganic/organic compounds.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Polymorphism and Vibrational Properties of MnMoO₄Microcrystals Prepared by a Hydrothermal Process

Martins

Coelho

Siqueira

et al. 2018

Crystal Growth & Design

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MnMoO4 microcrystals were synthesized by hydrothermal methods, and their structural, morphological, and vibrational properties were investigated. Conventional reactors and microwave-heated hydrothermal vessels were used to synthesize micrometer-sized MnMoO4 polymorphs at different temperature and time conditions. MnMoO4·H2O crystals were obtained in both reactors at temperatures below 200 °C, for times up to 24 h. These microcrystals belong to the triclinic P1̅ space group, and their 26 characteristic Raman bands were identified. A monoclinic MnMoO4 polymorph belonging to the P2/c structure was synthesized at temperatures higher than 200 °C only into conventional hydrothermal reactors. Polarized micro-Raman analyses have evidenced and allowed the assignment of 18 phonon modes predicted by group-theory calculations for this polymorph. Another MnMoO4 polymorph, within the monoclinic C2/m space group, was obtained by two processing routes: (i) heating the P2/c microcrystals at 600 °C; or (ii) heating the MnMoO4·H2O phase at 250 °C. For this monoclinic phase, 33 Raman-active bands were identified and assigned, in very good agreement with group-theoretical calculations, which predict 36 modes for the C2/m polymorph. Well-faceted, highly crystalline microcrystals were clearly observed by scanning and transmission electron microscopies, in perfect agreement with X-ray diffraction and Raman spectroscopic analysis. Finally, the appearance of characteristic phonon modes related to molybdenum in octahedral coordination suggests an incipient crystallization of a new, unreported α-MnMoO4 polymorph, at least in a short-range degree.

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“…The product was fabricated by a facile two-step hydrothermal route based on previous articles. − First, a copper mesh (400 mesh, 8 × 8 cm 2 ) was ultrasonically cleaned for 15 min in acetone, ethanol, and deionized water. The MnCO 3 -coated mesh was synthesized by a hydrothermal route: 0.0125 mol of MnCl 2 ·4H 2 O and 0.0125 mol of sodium citrate were dissolved in 100 mL of deionized water, and the solution was stirred for 30 min.…”

Section: Methodsmentioning

confidence: 99%

Durable and Stable MnMoO₄-Coated Copper Mesh for Highly Efficient Oil-in-Water Emulsion Separation and Photodegradation of Organic Contaminants

Chen

et al. 2019

ACS Appl. Mater. Interfaces

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Wastewater pollution has always been a major environmental problem worldwide. Furthermore, in light of the frequent oil spills that have occurred in recent years, the treatment of oily wastewater is particularly important. Herein, a MnMoO4-coated copper mesh was synthesized via a facile two-step hydrothermal route for application in the separation of oil-in-water emulsions. The mesh showed exceptional wettability and separation efficiency (more than 99.9% for toluene-in-water emulsions). In addition, the mesh possessed excellent photocatalytic activity toward the photodegradation of organic dyes in emulsions. The findings also demonstrated the durability and stability of the mesh, as evidenced by the sustained high separation efficiency that they displayed after abrasion or corrosion. Taken together, the findings indicate that the mesh prepared herein has great potential for application in oily wastewater treatment.

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Novel microwave-assisted synthesis of leaf-like MnMoO4 nanostructures and investigation of their photocatalytic performance

Cited by 25 publications

References 23 publications

Engineering the Electronic Structure of Mo Sites in Mn–Mo–O Mixed-Metal Oxides for Efficient Aerobic Oxidative Desulfurization

Engineering the Electronic Structure of Mo Sites in Mn–Mo–O Mixed-Metal Oxides for Efficient Aerobic Oxidative Desulfurization

Investigation of Polymorphism and Vibrational Properties of MnMoO₄Microcrystals Prepared by a Hydrothermal Process

Durable and Stable MnMoO₄-Coated Copper Mesh for Highly Efficient Oil-in-Water Emulsion Separation and Photodegradation of Organic Contaminants

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Novel microwave-assisted synthesis of leaf-like MnMoO4 nanostructures and investigation of their photocatalytic performance

Cited by 25 publications

References 23 publications

Engineering the Electronic Structure of Mo Sites in Mn–Mo–O Mixed-Metal Oxides for Efficient Aerobic Oxidative Desulfurization

Engineering the Electronic Structure of Mo Sites in Mn–Mo–O Mixed-Metal Oxides for Efficient Aerobic Oxidative Desulfurization

Investigation of Polymorphism and Vibrational Properties of MnMoO4Microcrystals Prepared by a Hydrothermal Process

Durable and Stable MnMoO4-Coated Copper Mesh for Highly Efficient Oil-in-Water Emulsion Separation and Photodegradation of Organic Contaminants

Contact Info

Product

Resources

About

Investigation of Polymorphism and Vibrational Properties of MnMoO₄Microcrystals Prepared by a Hydrothermal Process

Durable and Stable MnMoO₄-Coated Copper Mesh for Highly Efficient Oil-in-Water Emulsion Separation and Photodegradation of Organic Contaminants