GEOCHIMICA ET COSMOCHIMICA ACTA
·
2012
·
IF 4.259
Hui Yin,Wenfeng Tan,Lirong Zheng,Haojie Cui,Guohong Qiu,Fan Liu,Xionghan Feng
Hexagonal birnessite is the most ubiquitous manganese oxide in geological environments. It is often highly enriched in trace metal ions such as Ni and plays an important role in metal(loids) geochemistry . Nanostructured birnessites containing different amounts of Ni were synthesized by addition of Ni 2+ to initial reactants. Powder X-ray diffraction (XRD), element analysis, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), X-ray absorption spectroscopy (XAS) and isothermal adsorption and oxidation of metal(loids) were carried out to investigate the effects of Ni doping on the substructure and physicochemical properties of birnessite, and Ni crystal chemistry in birnessite. These Ni-rich birnessites have Ni contents as high as 2.99% (Ni5) and 6.08% (Ni10) in weight. EXAFS results show that Ni5 has 23.7% of the total Ni (0.71 wt.%) and Ni10 has 34.5% of the total Ni (2.10 wt.%) in Mn octahedral layer with the remaining Ni located at vacancies and edge sites. The Ni-rich birnessites have weaker crystallinity and thermal stability, fewer layers stacked along the c axis, ∼1.5–2.7 times larger surfaces areas, and a higher Mn average oxidation numbers (AONs) compared to the birnessite without Ni. Additionally, the doping of Ni during birnessite crystallization enhances the formation of vacancies in the layer; however, adsorption capacities for Pb 2+ and Zn 2+ by these Ni-rich birnessites are reduced, mainly because of vacancies and edge sites occupation by a large amount of Ni. The Ni-rich birnessites exhibit much higher oxidation capability and can completely oxidize As(III) in solution at rapid initial reaction rates under the experimental condition. The results indicate that incorporation of Ni into the natural birnessite in ferromanganese nodules may be achieved both by direct coprecipitation with Mn to build the layers and migration over time from adsorbed Ni on the surface into the layer structure. It is also implied that Ni doping in birnessite has great impact on the geochemical behaviors of heavy metals, either in adsorption or oxidation reactions.
研究领域:
地球化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 13
·7440-7446
·
IF 3.049
Fan Liu,Liming Wang,Weijun Yang,Enqing Liu,Can Huang
High purity birnessite was synthesized and exfoliated into a negatively charged monolayer structure. A positively charged 5, 10, 15, 20-tetrakis (4-aminophenyl) manganese porphyrin (MnTAPP) was synthesized. Driven by the electrostatic force and the coordination effect of the amino nitrogen on the manganese ion in birnessite, the single-layer birnessite was reassembled with MnTAPP, forming a new sandwich-type catalytic composite MnTAPP@bir. The structure and chemical properties of the composite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Brunauer–Emmett analysis (BET). Electrocatalytic studies showed that the MnTAPP@bir exhibited an overpotential for water oxidation of 450 mV (at 10 mA cm−2) and a Tafel slope of 121.5 mV dec−1 compared to birnessite with 700 mV (at 10 mA cm−2) and 230 mV dec−1. Impedance spectroscopy results suggested that the charge transfer resistivity of MnTAPP@bir was significantly lower than that of birnessite, suggesting that MnTAPP in the interlayer increased the conductivity of birnessite. Through a chronoamperometry test, the new material also showed excellent stability within 4000 s.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Changye Mang,Guanghui Li,Xin Zhang,Jun Luo,Hao Jiang,Tao Jiang
Manganese oxide is a promising catalyst used for HCHO oxidation. However, its unsatisfactory catalytic performance hinders its practical applications at ambient temperature. This study reported porous birnessite nanospheres with high thermal catalytic and photocatalytic properties for HCHO decomposition, which were synthesized via a seed-mediated growth method. The spherical birnessite seeds with a particle size of ∼100 nm were first obtained from pyrolusite–pyrite acid leaching solution and then grew to porous spheres with particles size of 600–800 nm through a hydrothermal process at a temperature of 200 °C for 20 h. With the particles growing by regulating the synthesis temperature and time, the peak intensity of the Mn–O–Mn band and hydroxyl groups in birnessite gradually increased, and the average oxidation state of Mn decreased. These changes improved the catalytic ability of birnessite, further confirmed by catalytic tests. The birnessite nanospheres having optimum catalytic performance demonstrated 59.5 and 64.8% HCHO conversion for thermal catalysis and photocatalysis, respectively. Evidently, this work provides a short process for the direct synthesis of birnessite from an untreated pyrolusite–pyrite acid leaching solution, and its thermal catalytic and photocatalytic oxidation performance in decomposition of formaldehyde had an obvious improvement compared with that of previous reports.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 32
·期 14
·2108267
·
IF 18.808
Ang Gao,Jiannian Xia,Min Li,Xia Lu,Feng Wang,Ru Yang
Crystal water mediated ion hydration and transport is a fundamental physicochemical process in a wide range of applications and natural processes, such as crystal water containing battery materials. In this context, K-Birnessite with interlaminar H 2 O (K 0.21 MnO 2 ⋅0.31H 2 O) is reported for nonaqueous potassium-ion storage with enhanced capacity and rate performance. It is clarified that the water–solid interface plays an important role in building and stabilizing the K-Birnessite layered structure and facilitating the K + diffusion for the K-ion battery system. In addition to the enlarged ionic channel dimensions and effective shielding of the electrostatic interaction with K + , the concerted diffusion of K + /H 2 O with the rotation of H 2 O molecules is further revealed to account for the quite low activation energies by first-principles simulations. Moreover, the interlayer H 2 O exerts on the electronic structures, and thus on the electrochemical voltage to result in the competition between the split of crystal field (“∇ JT ”) and the electronic superexchange interaction (“O w -K-O”) in the K-Birnessite structure. The results provide new insights into hydrated ion kinetics and open an exciting direction for battery material design.
研究领域:
材料科学
·
电化学
·
储能
·
计算材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Xiuying Liu,Jiao Zhou,Qianna Xia,Bowen Li,Qiaohui Gao,Shuaiqi Zhao,Aimal Khan,Aihua Xu,Xiaoxia Li
The development of efficient and eco-friendly Mn-based hybrids for the degradation of biorefractory organic pollutants via peroxymonosulfate (PMS) activation is highly desired. In this study, a novel graphite nanosheet (GNs)-based Fe-Mn bimetallic oxide (Fe doped birnessite MnO 2 , FeMn/GNs) was synthesized under mild conditions. Compared with monometallic Fe or Mn oxide on GNs, FeMn/GNs exhibited a higher surface area, decreased Mn oxidation states, stronger interaction with GNs, and more active sites for PMS adsorption. Among different Fe/Mn ratios, Fe 2 Mn 1 /GNs showed the optimum performance for bisphenol A (BPA) degradation with the first-order rate constant of 0.22 min −1 , which was about 8.5 and 12.9 times higher than that of Mn/GNs and Fe/GNs, respectively. Different from the pollutant-catalyst-PMS electron transfer mechanism for Mn/GNs, the direct two-electron transfer in FeMn/GNs+PMS system, was mainly processed between the simultaneously activated BPA and PMS. This was probably based on the double adsorption sites of Fe and Mn species on the same catalyst: PMS was adsorbed by Fe species through hydroxyl groups, while BPA was mainly coordinated with Mn species due to the layered structure and hydrophobicity of the Mn oxide. This study is expected to provide the rational design of efficient Mn-based hybrids for PMS activation.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Junxin Jia,Yaqi Jiao,Jiaying Gu,Tianyuan Zhang,Qin Zhou,Hui Li,Sa Wang,Hongliang Guo,Hongtao Shi,Li Li
Phenanthrene (PHE) serves as a representative polycyclic aromatic hydrocarbon (PAH) that poses a significant risk to ecosystems and human health owing to its persistence and biotoxicity. A novel bio-mineral system was developed by integrating natural birnessite with the PHE-degrading strain Novosphingobium sp. HDJX-2 to address the need for effective remediation, which achieved the complete degradation of PHE within 72 h. The mechanistic analysis demonstrated that the enhanced degradation efficiency resulted from multidimensional synergism between minerals and microbes. The metabolic activity of HDJX-2 modified the microstructure of birnessite and increased its active sites, whereas birnessite simultaneously stimulated cellular activity and markedly promoted the secretion of bound extracellular polymeric substances (B-EPS). Additionally, birnessite induced the expression of more hydrophobic proteins, thereby enhancing the recognition and binding capacity of EPS for hydrophobic PHE molecules. This structural modification was accompanied by increased glucose (Glc) and glucosamine (GalN) contents, which reduced microbial aggregation and improved cell dispersion, facilitating pollutant accessibility and metabolism. Furthermore, the phenolic compounds in EPS were involved in synergistic coupling with birnessite. This contributed to the formation of high-molecular-weight, highly aromatic, and highly unsaturated polymeric products, further enhancing the PHE adsorption, enrichment, and catalytic degradation. This study offers theoretical support and practical framework for the development of efficient and sustainable PAH remediation strategies.
✓ 已验证
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Nan Qiu,Hong Chen,Zhaoming Yang,Sen Sun,Yuan Wang
A highly reversible aqueous rechargeable battery system is assembled by using a Zn anode, a room-temperature synthesized MnO 2 -birnessite cathode and a mild ZnSO 4 -based aqueous electrolyte with MnSO 4 as an additive. Structural analysis reveal that MnO 2 -birnessite undergoes a structural transformation to poorly crystalline MnO 2 . It offers an operating voltage of 1.39 V, an energy density of 364 Wh kg −1 (cathode only) at 200 mA g −1 and shows a capacity retention of 100% over 400 cycles at 500 mA g −1 . This low-cost battery system is a promising candidate for large-scale energy storage.
研究领域:
材料科学
·
电化学
·
储能技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 12
·5719-5725
·
IF 8.867
Jinlong Wang,Gaoke Zhang,Pengyi Zhang
Catalytic reaction active sites tend to be structural defects, such as edges, corners and ribs which have a low coordination number. Here, a kind of layered MnO2 (birnessite) with irregular surface pits was successfully synthesized and investigated for the catalytic oxidation of formaldehyde. The surface pits were generated by a series of chemical surface modifications. Tetrabutylammonium hydroxide (TBAOH) played a key role in generating surface pits, which entered the interlayer from the edge of acid-treated MnO2 and weakened the van der Waals force between interlayers. The steric effects of TBAOH lead to the generation of irregular surface pits. The presence of surface pits not only provided larger specific surface areas but also led to more unsaturated manganese and oxygen atoms, which promoted formaldehyde adsorption and oxygen activation. As a result, birnessite-type MnO2 with surface pits exhibited a lower apparent activation energy than the pristine one (37.6 versus 55.4 kJ mol−1) for 200 ppm of HCHO under a GHSV of 120 000 mL g−1 h−1 and ∼45% relative humidity. These findings open up a new way to generate surface pits on layered 2D materials, holding promise for designing highly efficient catalysts by creating active centers.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Separations
·
2025
·Vol. 12
·期 12
·
IF 2.7
Meiqing Chen,Wenjie Dai,Yingying Liu,Guanzheng Zhuang,Yanfu Wei,Zhi Dang,Pingxiao Wu
Birnessite has a strong ability to fix rare-earth elements (REEs), but the transformation process of birnessite and its effects on the migration of these elements are not well understood. This study examines how pH and Mn(II) concentrations influence the transformation of cerium-adsorbed hexagonal birnessite (Ce/HB) and the behaviors of Ce and Mn. The results show that the effect of Mn(II) on Ce/HB transformation strongly depended on solution pH. At a pH of 5.0, HB initially underwent transformation into feitknechtite, followed by further disproportionation that resulted in the regeneration of HB and Mn(II). Concurrently, redox reactions occur between Mn(IV) in MnO2(a secondary phase of HB) and Ce(III)/Mn(II), creating a local redox gradient that facilitates partial HB transformation. At pH = 7.0, Mn(II) reduces the crystallinity of transformed products while enhancing the thermodynamic stability of feitknechtite, making it the dominant manganese oxide phase. At pH = 9.0, high-concentration Mn(II) causes lattice distortion in original HB; Ce(III) acts as a structural inducer, promoting mineral transition from hexagonal to orthorhombic symmetry, while excess soluble Mn(II) precipitates new feitknechtite. Additionally, surplus Mn(II) could engage in interfacial redox reactions with high-valent manganese oxides to generate secondary feitknechtite. Ce primarily exists as Ce(IV), forming CeO2on the mineral surface via oxidation reactions that significantly increase hydroxylation and surface reactivity. This study clarifies the transformation pathways of manganese oxides and the migration and transformation patterns of Ce and Mn in rare-earth-rich mining areas.
✓ 已验证
产品关联
DOI
高影响因子
Toxics
·
2025
·Vol. 13
·期 4
·262
·
IF 4.1
Wei Zhang,Huan Yang,Shaohong You,Xia Zhong,Pingping Jiang,Xudong Lan,Rui Ma
Current research focuses more on redox of toxic Cr(VI), with less attention to Cr(III) changes in flooded soil. First, the structure of acid birnessite and cryptomelane was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and other test methods. This study investigated farmland soil in Yuxi, Yunnan Province, under flooding stress induced by the addition of two distinct concentrations of manganese oxides. Throughout the experiment, key physicochemical properties of the soil—including pH, redox potential (Eh), Cr(VI) concentration, and chromium speciation—were systematically measured and analyzed. Structural characterization demonstrated distinct morphological and surface area properties. Specifically, acid birnessite, with petal-like stacked spheres, has a specific surface area of 103.76 m2/g, while cryptomelane, strip-shaped, has an area of 95.92 m2/g. The submergence experiment yielded the following phenomena: (1) During the 60-day flooding experiment, soil amended with 0.5% or 1% acid birnessite or cryptomelane exhibited an increase in Eh compared to the control group. (2) At the end of the 60-day submergence period, the Cr(VI) concentration in the soil treated with 1% acid birnessite increased by 2.4 times compared to the control group. In addition, after 60 days, Cr(VI) concentrations in the soil exceeded 5 mg/L in soils with manganese oxide added to them. This study evaluates how manganese oxides oxidize Cr(III), aiding in assessing their environmental risks and long-term impacts on metal transformation. The findings help predict chromium behavior in farm soils and guide remediation strategies.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano-Micro Letters
·
2020
·Vol. 12
·期 1
·1-15
·
IF 12.264
Zhai Xian-Zhi,Qu Jin,Hao Shu-Meng,Jing Ya-Qiong,Chang Wei,Wang Juan,Li Wei,Abdelkrim Yasmine,Yuan Hongfu,Yu Zhong-Zhen
A layered sodium-ion/crystal water co-intercalated Na 0.55 Mn 2 O 4 ·0.57H 2 O (NMOH) cathode is synthesized successfully with a selectively etching method for zinc-ion batteries.
A displacement/intercalation mechanism is confirmed in the Mn-based cathode for the first time.
The NMOH cathode delivers a competitive reversible capacity of 201.6 mA h g −1 at 500 mA g −1 after 400 cycles.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2021
·Vol. 17
·期 45
·2104557
·
IF 13.281
Guolong Wang,Yaling Wang,Boyuan Guan,Jiamei Liu,Yan Zhang,Xiaowei Shi,Cheng Tang,Guohong Li,Yingbo Li,Xiao Wang,Lei Li
MnO 2 -based material is one of the most promising cathode candidates of aqueous zinc-ion batteries (ZIBs), but its commercialization is hindered by the sluggish reaction kinetics and poor structural stability. Herein, a hierarchical framework consisting of core–shell structured carbon nanotubes@K-birnessite-MnO 2 enwrapped by graphene/carbon black bicomponent networks (CNT@KMO@GC) via a simple method for ZIBs is designed and developed. The hierarchical framework characterized with favorable K + preintercalation, δ-phase, and vertically aligned nanoflake arrays of KMO and 3D electrically conductive network shows the enhanced electronic/ionic conductivity and improved wettability with electrolyte, resulting in the fast charge/mass transport and stable structural stability of CNT@KMO@GC. When used as cathode in ZIBs, CNT@KMO@GC exhibits exciting electrochemical performance with remarkable capacity (405.5 mAh g −1 at 0.30 A g −1 ), high rate performance (166.6 mAh g −1 up to 10.0 A g −1 ), and impressive cycling stability (almost no capacity decay after 2000 cycles and 77.3% retention after 10 000 cycles at 10.0 A g −1 ). The energy storage mechanism of CNT@KMO@GC is clarified as H + /Zn 2+ coinsertion/extraction via electrochemical analysis and ex situ characterization. This study offers an innovative paradigm for the advance of ZIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
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