Self-assembly of birnessite nanoflowers by staged three-dimensional oriented attachment

Liang, Xinran; Zhao, Zixiang; Zhu, Mengqiang; Liu, Fan; Wang, Lijun; Yin, Hui; Qiu, Guohong; Cao, Fuyang; Liu, Xiaoqing; Feng, Xionghan

doi:10.1039/c6en00619a

Cited by 20 publications

(13 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the basis of the synthesis method and the birnessite structure characteristics revealed by XRD and transmission electron microscopy, the structure of the present samples should be the same as that of birnessite synthesized by Liang et al According to Liang et al, oriented δ-MnO 2 nanoflakes with poor crystallinity are generated in the initial stage of the reaction and in the course of time these flakes aggregate and form randomly oriented nanosheets resembling petals. During Ostwald-ripening the nanosheets rotate to achieve the same lattice direction and convert into birnessite.…”

Section: Resultsmentioning

confidence: 92%

CD-MUSIC-EDL Modeling of Pb²⁺ Adsorption on Birnessites: Role of Vacant and Edge Sites

Zhao

Tan

Wang

et al. 2018

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

The surface complexation modeling of metal adsorption to birnessites is in its infancy compared to the charge-distribution multisite ion complexation (CD-MUSIC) models for iron/aluminum (hydr)oxides. Therefore, using X-ray diffraction with Rietveld refinement to obtain the reactive sites and their densities, a CD-MUSIC model combined with a Stern-Gouy-Chapman electrical double layer (EDL) model for the external surface and a Donnan model for the interlayer surface is developed for birnessites with different Mn average oxidation state (MnAOS). Proton affinity constants and the charge distributions of Pb surface complexes were calculated a priori. By fitting Pb adsorption data to the model the obtained equilibrium constants (log K) of Pb complexes were 6.9-10.9 for the double-corner-sharing and double-edge-sharing Pb complexes on the edge sites and 2.2-6.5 for the triple-corner-sharing Pb complex on the vacancies. The larger log K value was obtained for higher MnAOS. Speciation calculations showed that with increasing MnAOS from 3.67 to 3.92 the interlayer surface contribution to the total Pb adsorption increased from 43.2% to 48.6%, and the vacancy contribution increased from 43.9% to 54.7%. The vacancy contribution from interlayer surface was predominant. The present CD-MUSIC-EDL model contributes to understand better the difference in metal adsorption mechanism between birnessite and iron/aluminum (hydr)oxides.

show abstract

Section: Resultsmentioning

confidence: 92%

CD-MUSIC-EDL Modeling of Pb²⁺ Adsorption on Birnessites: Role of Vacant and Edge Sites

Zhao

Tan

Wang

et al. 2018

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The MnO 2 structure of birnessite is formally composed of stacked sheets of edge-sharing MnO 6 octahedra (Figure ) − and forms ultrathin nanoplatelets with a surface dominated with its basal face. , It has a formal average oxidation state (AOS) of 4.0, but synthetic and natural forms commonly contain a mixture of Mn oxidation states (Mn IV , Mn III , and Mn II ). − In nature, birnessite or vernadite with AOS values as low as ∼3.5 is probably more common because natural organic matter has a strong propensity to reduce Mn IV . ,− Cationic vacancies represent an additional source of charge imbalance with, for example, previously reported populations of 12% in birnessite prepared in acidic and 6% in alkaline media. ,, Countercations ( e.g. , Na + , K + , and Mn 2+ ) in the interlayer region counterbalance the missing charges resulting from the mixed Mn-oxidation states and vacancies.…”

Section: Introductionmentioning

confidence: 99%

“…13 Examples of knowledge required for these various applications include molecular configurations 14 of intercalated water layers and of their thermal stabilities 4,15 The MnO 2 structure of birnessite is formally composed of stacked sheets of edge-sharing MnO 6 octahedra (Figure 1) 16−18 and forms ultrathin nanoplatelets with a surface dominated with its basal face. 19,20 It has a formal average oxidation state (AOS) of 4.0, but synthetic and natural forms commonly contain a mixture of Mn oxidation states (Mn IV , Mn III , and Mn II ). 21−24 In nature, birnessite or vernadite with AOS values as low as ∼3.5 is probably more common because natural organic matter has a strong propensity to reduce Mn IV .…”

Section: ■ Introductionmentioning

confidence: 99%

Nanoscale Hydration in Layered Manganese Oxides

et al. 2021

View full text Add to dashboard Cite

Birnessite is a layered MnO 2 mineral capable of intercalating nanometric water films in its bulk. With its variable distributions of Mn oxidation states (Mn IV , Mn III , and Mn II ), cationic vacancies, and interlayer cationic populations, birnessite plays key roles in catalysis, energy storage solutions, and environmental (geo)chemistry. We here report the molecular controls driving the nanoscale intercalation of water in potassium-exchanged birnessite nanoparticles. From microgravimetry, vibrational spectroscopy, and X-ray diffraction, we find that birnessite intercalates no more than one monolayer of water per interlayer when exposed to water vapor at 25 °C, even near the dew point. Molecular dynamics showed that a single monolayer is an energetically favorable hydration state that consists of 1.33 water molecules per unit cell. This monolayer is stabilized by concerted potassium–water and direct water–birnessite interactions, and involves negligible water–water interactions. Using our composite adsorption–condensation–intercalation model, we predicted humidity-dependent water loadings in terms of water intercalated in the internal and adsorbed at external basal faces, the proportions of which vary with particle size. The model also accounts for additional populations condensed on and between particles. By describing the nanoscale hydration of birnessite, our work secures a path for understanding the water-driven catalytic chemistry that this important layered manganese oxide mineral can host in natural and technological settings.

show abstract

“…Such XRD patterns have been reported in the literature. 47−49 For example, the XRD pattern similar to Figure 3 with the absence of basal reflections was observed in the early stages of birnessite formation before the sheets had an opportunity to stack up along the c axis. 47 In another study, with increasing Al 3+ and Fe 3+ introduced during the synthesis of birnessite, the basal reflections disappeared.…”

Section: Resultsmentioning

confidence: 87%

Photochemical Water Oxidation in a Buffered Tris(2,2′-bipyridyl)ruthenium–Persulfate System Using Iron(III)-Modified Potassium Manganese Oxides as Catalysts

Shrestha

Dutta

2018

ACS Omega

View full text Add to dashboard Cite

Study of manganese oxides for electrocatalytic and photocatalytic oxidation of water is an active area of research. The starting material in this study is a high-surface-area disordered birnessite-like material with K + in the interlayers (KMnOx). Upon ion-exchange with Fe 3+ , the disordered layer structure collapses (Fe(IE)MnOx), and the surface area is slightly increased. Structural analysis of the Fe(IE)MnOx included examination of its morphology, crystal structure, vibrational spectra, and manganese oxidation states. Using the Ru(bpy) 3 2+ –persulfate system, the dissolved and headspace oxygen upon visible light photolysis with highly dispersed Fe(IE)MnOx was measured. The photocatalytic activity for O 2 evolution of the Fe(IE)MnOx was three times better than KMnOx, with the highest rate being 9.3 mmol O 2 mol Mn –1 s –1 . The improvement of the photocatalytic activity was proposed to arise from the increased disorder and interaction of Fe 3+ with the MnO 6 octahedra. As a benchmark, colloidal IrO 2 was a better photocatalyst by a factor of ∼75 over Fe(IE)MnOx.

show abstract

Self-assembly of birnessite nanoflowers by staged three-dimensional oriented attachment

Abstract: Assembly of birnessite nanoflowers via a two-directional oriented attachment process.

Cited by 20 publications

References 61 publications

CD-MUSIC-EDL Modeling of Pb²⁺ Adsorption on Birnessites: Role of Vacant and Edge Sites

CD-MUSIC-EDL Modeling of Pb²⁺ Adsorption on Birnessites: Role of Vacant and Edge Sites

Nanoscale Hydration in Layered Manganese Oxides

Photochemical Water Oxidation in a Buffered Tris(2,2′-bipyridyl)ruthenium–Persulfate System Using Iron(III)-Modified Potassium Manganese Oxides as Catalysts

Contact Info

Product

Resources

About

Self-assembly of birnessite nanoflowers by staged three-dimensional oriented attachment

Abstract: Assembly of birnessite nanoflowers via a two-directional oriented attachment process.

Cited by 20 publications

References 61 publications

CD-MUSIC-EDL Modeling of Pb2+ Adsorption on Birnessites: Role of Vacant and Edge Sites

CD-MUSIC-EDL Modeling of Pb2+ Adsorption on Birnessites: Role of Vacant and Edge Sites

Nanoscale Hydration in Layered Manganese Oxides

Photochemical Water Oxidation in a Buffered Tris(2,2′-bipyridyl)ruthenium–Persulfate System Using Iron(III)-Modified Potassium Manganese Oxides as Catalysts

Contact Info

Product

Resources

About

CD-MUSIC-EDL Modeling of Pb²⁺ Adsorption on Birnessites: Role of Vacant and Edge Sites

CD-MUSIC-EDL Modeling of Pb²⁺ Adsorption on Birnessites: Role of Vacant and Edge Sites