Inflating Strategy To Form Ultrathin Hollow MnO<sub>2</sub> Nanoballoons

Among transition metal oxides, MnO2 is of considerable importance for various technological end-uses, from heterogeneous catalysis to gas sensing, owing to its structural flexibility and unique properties at the nanoscale. In this work, we demonstrate the successful fabrication of supported MnO2 nanomaterials by a catalyst-free, plasma-assisted process starting from a fluorinated manganese(II) molecular source in Ar/O2 plasmas. A thorough multitechnique characterization aimed at the systematic investigation of material structure, chemical composition, and morphology revealed the formation of F-doped, oxygen-deficient, MnO2-based nanomaterials, with a fluorine content tunable as a function of growth temperature (T G). Whereas phase-pure β-MnO2 was obtained for 100 °C ≤ T G ≤ 300 °C, the formation of mixed phase MnO2 + Mn2O3 nanosystems took place at 400 °C. In addition, the system nano-organization could be finely tailored, resulting in a controllable evolution from wheat-ear columnar arrays to high aspect ratio pointed-tip nanorod assemblies. Concomitantly, magnetic force microscopy analyses suggested the formation of spin domains with features dependent on material morphology. Preliminary tests in Vis-light activated photocatalytic degradation of rhodamine B aqueous solutions pave the way to possible applications of the target materials in wastewater purification.

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“…The average crystallite sizes D were estimated from the patterns presented in Figure 2a by using the Scherrer formula: [8][9][10][11][12][13][14]…”

Section: S3mentioning

confidence: 99%

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO₂ Nanomaterials

et al. 2018

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“…The exploration and development of Mn‐based oxides (or MnO x ) have been a hot spot for energy storage due to their low cost, high theoretical capacity (≈756 mAh g −1 ), low environmental pollution, and large reserves . Nevertheless, like other transition metal oxides, MnO‐based materials also suffer from typical problems, such as poor durability upon cycling, self‐aggregation, and low electrical conductivity (≈10 −5 –10 −6 S cm −1 for Mn 3 O 4 ), which greatly impede their application in energy storage . Consequently, it is still a great challenge to develop Mn‐based oxides with excellent performance.…”

Section: Introductionmentioning

confidence: 99%

Spray‐Assisted Synthesis of MnO@C/Graphene Composites as Electrode Materials for Supercapacitors

et al. 2019

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The preparation of a composite consisting of amorphous carbon‐coated MnO nanoparticles deposited on graphene sheets (i.e., MnO@C/rGO) by a spray‐assisted method is reported. The MnO@C/rGO composite used as an active material for supercapacitors exhibits an excellent cyclability and a high specific capacitance in a two‐electrode system using 2 mol L−1 KOH aqueous solution as the electrolyte. High specific capacitances of 264 and 176 F g−1 at current densities of 1 and 20 A g−1, respectively, are achieved. A rate‐capability retention of about 67% is obtained when the current density increases from 1 to 20 A g−1, and the specific capacitance is retained at 78% after 10 000 cycles at a current density of 20 A g−1. The excellent electrochemical performance of the MnO@C/rGO is ascribed to the integration of graphene and the coating of amorphous carbon derived from glucose, which significantly improves the conductivity and alleviates the agglomeration of MnO. The unique architecture and good electrical conductivity increase the specific surface area and provide continuous electrical contact during the charge/discharge process. It is shown that carbon coating is an effective way to improve the electrochemical performance of metal oxides/graphene composites.

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Section: Modification Of Mno2 Single Species Nanomaterialsmentioning

confidence: 99%

MnO₂‐Based Materials for Environmental Applications

et al. 2021

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Manganese dioxide (MnO2) is a promising photo–thermo–electric‐responsive semiconductor material for environmental applications, owing to its various favorable properties. However, the unsatisfactory environmental purification efficiency of this material has limited its further applications. Fortunately, in the last few years, significant efforts have been undertaken for improving the environmental purification efficiency of this material and understanding its underlying mechanism. Here, the aim is to summarize the recent experimental and computational research progress in the modification of MnO2 single species by morphology control, structure construction, facet engineering, and element doping. Moreover, the design and fabrication of MnO2‐based composites via the construction of homojunctions and MnO2/semiconductor/conductor binary/ternary heterojunctions is discussed. Their applications in environmental purification systems, either as an adsorbent material for removing heavy metals, dyes, and microwave (MW) pollution, or as a thermal catalyst, photocatalyst, and electrocatalyst for the degradation of pollutants (water and gas, organic and inorganic) are also highlighted. Finally, the research gaps are summarized and a perspective on the challenges and the direction of future research in nanostructured MnO2‐based materials in the field of environmental applications is presented. Therefore, basic guidance for rational design and fabrication of high‐efficiency MnO2‐based materials for comprehensive environmental applications is provided.

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Inflating Strategy To Form Ultrathin Hollow MnO₂ Nanoballoons

Cited by 41 publications

References 50 publications

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO₂ Nanomaterials

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO₂ Nanomaterials

Spray‐Assisted Synthesis of MnO@C/Graphene Composites as Electrode Materials for Supercapacitors

MnO₂‐Based Materials for Environmental Applications

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Inflating Strategy To Form Ultrathin Hollow MnO2 Nanoballoons

Cited by 41 publications

References 50 publications

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO2 Nanomaterials

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO2 Nanomaterials

Spray‐Assisted Synthesis of MnO@C/Graphene Composites as Electrode Materials for Supercapacitors

MnO2‐Based Materials for Environmental Applications

Contact Info

Product

Resources

About

Inflating Strategy To Form Ultrathin Hollow MnO₂ Nanoballoons

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO₂ Nanomaterials

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO₂ Nanomaterials

MnO₂‐Based Materials for Environmental Applications