JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Yuhui Xu,Gaini Zhang,Xiaoxue Wang,Xiangyang Li,Jianhua Zhang,Xinyue Wu,Yitong Yuan,Yukun Xi,Xuan Yang,Ming Li,Xiaohua Pu,Guiqiang Cao,Zihao Yang,Bo Sun,Jingjing Wang,Huijuan Yang,Wenbin Li,Jiujun Zhang,Xifei Li
Birnessite-type MnO 2 (δ-MnO 2 ) exhibits great potential as a cathode material for aqueous zinc-ion batteries (AZIBs). However, the structural instability and sluggish reaction kinetics restrict its further application. Herein, a unique protons intercalation strategy was utilized to simultaneously modify the interlayer environment and transition metal layers of δ-MnO 2 . The intercalated protons directly form strong O H bonds with the adjacent oxygens, while the increased H 2 O molecules also establish a hydrogen bond network (O H···O) between H 2 O molecules or bond with adjacent oxygens. Based on the Grotthuss mechanism, these bondings ultimately enhance the stability of layered structures and facilitate the rapid diffusion of protons. Moreover, the introduction of protons induces numerous oxygen vacancies , reduces steric hindrance , and accelerates ion transport kinetics. Consequently, the protons intercalated δ-MnO 2 (H-MnO 2-x ) demonstrates exceptional specific capacity of 401.7 mAh/g at 0.1 A/g and a fast-charging performance over 1000 cycles. Density functional theory analysis confirms the improved electronic conductivity and reduced diffusion energy barrier. Most importantly, electrochemical quartz crystal microbalance tests combining with ex-situ characterizations verify the inhibitory effect of the interlayer proton environment on basic zinc sulfate formation. Protons intercalation behavior provides a promising avenue for the development of MnO 2 as well as other cathodes in AZIBs.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Yaoyang Xia,Hao Xiang,Fu Wan,Ruiqi Liu,Kaida Hu,Yujie Zheng,Quan Zhou,Weigen Chen
Aqueous zinc ion batteries (AZIBs) with MnO 2 as the positive electrode have attracted extensive attention due to their high theoretical energy density. However, the dissolution of the positive electrode and the poor conductivity during the cycling process affect its development prospects. In this paper, δ-MnO 2 with larger interlayer spacing is adopted, and pre-intercalation of Ni 2+ is used to further expand its interlayer spacing to enhance the diffusion kinetics of Zn 2+ in the cathode. Density functional theory (DFT) calculations show that the charge distribution around Mn and O atoms will be changed to improve the conductivity of the MnO 2 cathode by the Ni 2+ intercalation. However, the intercalation of metal cations will lead to the production of more Mn 3+ . which will lead to further manganese dissolution. Therefore, we prepared a polyindole (PIn) coating layer with high conductivity and can effectively prevent cathode erosion by in-situ polymerization. The formation of a heterogeneous interface between PIn and MnO 2 surface not only provides more active electrochemical sites, but also enhances the conductivity of the cathode and reduces the occurrence of manganese dissolution, which greatly improves the cycle performance and specific capacity of the cathode. Ni-MnO 2 @PIn delivers a discharge capacity of 385 mAh g −1 at a current density of 0.1 A g −1 , and maintains a capacity of 278 mAh g −1 after 200 cycles at a current density of 0.3 A g −1 , with a capacity retention of 95 %.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Li Yongfeng,Liao Qianyan,Ling Weizhao,Ye Fan,Liu Fangfang,Zhang Xipeng,He Jiajun,Cheng Gao
Exploring high-efficiency and stable monolithic structured catalysts is vital for catalytic combustion of volatile organic compounds. Herein, we prepared a series of Pd/δ-MnO2 nanoflower arrays monolithic integrated catalysts (0.01–0.07 wt% theoretical Pd loading) via the hydrothermal growth of δ-MnO2 nanoflowers onto the honeycomb cordierite, which subsequently served as the carrier for loading the Pd nanoparticles (NPs) through the electroless plating route. Moreover, we characterized the resulting monolithic integrated catalysts in detail and evaluated their catalytic activities for toluene combustion, in comparison to the controlled samples including only Pd NPs loading and the δ-MnO2 nanoflower arrays. Amongst all the monolithic samples, the Pd/δ-MnO2 nanoflower arrays monolithic catalyst with 0.05 wt% theoretical Pd loading delivered the best catalytic performance, reaching 90% toluene conversion at 221°C at a gas hourly space velocity (GHSV) of 10,000 h−1. Moreover, this sample displayed superior catalytic activity for o-xylene combustion under a GHSV of 10,000 h−1. The monolithic sample with optimal catalytic activity also displayed excellent catalytic stability after 30 h constant reaction at 210 and 221°C.
研究领域:
环境科学
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催化材料
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 12
·6801-6806
·
IF 3.119
Pengyu Xiao,Yang Liu,Wenjing Zong,Jin Wang,Minghuo Wu,Jingjing Zhan,Xianliang Yi,Lifen Liu,Hao Zhou
Multiple enzyme-like activities of manganese oxides (MnO2) have been reported and applied in catalysis, biosensors, and cancer therapy. Here, we report that catechol can be determined colorimetrically based on the 3,3′,5,5′-tetramethylbenzidine (TMB) oxidase-like activity of δ-MnO2. The detection was based on pre-incubation of catechol containing water samples with δ-MnO2, and then the residual TMB oxidase-like activity of reacted δ-MnO2 was linearly dependent on the catechol concentration in the range of 0.5 to 10 μM. This determination method was stable at pH 3.73–6.00 and was not affected by ion strength up to 200 μM. Common co-solutes in water bodies (50 μM) have negligible effects and excellent selectivity of catechol among various phenolic compounds (15 μM) was facilitated. Both reduction and aggregation of δ-MnO2 were observed during the incubation process with catechol, and aggregation-induced TMB oxidase–mimic activity decrease was the main factor for this colorimetric determination.
研究领域:
分析化学
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环境科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Yanyi Liu,Wenhuan Yuan,Wenli Lin,Shan Yu,Lei Zhou,Qingyi Zeng,Jin Wang,Luoheng Tao,Qunwei Dai,Juan Liu
Even though uranium (U) is considered to be an essential strategic resource with vital significance to nuclear power development and climate change mitigation , U exposure to human and ecological environment has received growing concerns due to its both highly chemically toxic and radioactively hazardous property. In this study, a composite (M-BC) based on Ficus macrocarpa (banyan tree) aerial roots biochar (BC) modified by δ-MnO 2 was designed to separate U(VI) from synthetic wastewater. The results showed that the separation capacity of M-BC was 61.53 mg/g under the solid – liquid ratio of 1 g/L, which was significantly higher than that of BC (12.39 mg/g). The separation behavior of U(VI) both by BC and M-BC fitted well with Freundlich isothermal models, indicating multilayer adsorption occurring on heterogeneous surfaces. The reaction process was consistent with the pseudo-second-order kinetic model and the main rate-limiting step was particle diffusion process. It is worthy to note that the removal of U(VI) by M-BC was maintained at 94.56% even after five cycles, indicating excellent reusability and promising application potential. Multiple characterization techniques ( e.g. Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and X-ray Photoelectron Spectroscopy (XPS)) uncovered that U(VI) complexation with oxygen-containing functional groups ( e.g. O–C O and Mn–O) and cation exchange with protonated ≡MnOH were the dominant mechanisms for U(VI) removal. Application in real uranium wastewater treatment showed that 96% removal of U was achieved by M-BC and more than 92% of co-existing (potentially) toxic metals such as Tl, Co, Pb, Cu and Zn were simultaneously removed. The work verified a feasible candidate of banyan tree aerial roots biowaste based δ-MnO 2 -modified porous BC composites for efficient separation of U(VI) from uranium wastewater, which are beneficial to help address the dilemma between sustainability of nuclear power and subsequent hazard elimination.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 14
·6747-6755
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IF 8.867
Can Cao,Jian Xie,Shichao Zhang,Bin Pan,Gaoshao Cao,Xinbing Zhao
Lithium–oxygen (Li–O2) cells are receiving intense interest because of their extremely high energy density. A highly efficient catalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a key factor influencing the performance of lithium–oxygen cells. In this work, we prepared a highly efficient CeO2-decorated δ-MnO2 (CeO2/δ-MnO2) catalyst which is composed of graphene-like δ-MnO2 with ultrafine CeO2 nanocrystals decorated on it. Li–O2 cells with the CeO2/δ-MnO2 catalyst exhibit superior electrochemical performance, including high discharge specific capacity (8260 mA h g−1 at 100 mA g−1), good rate capability (735 mA h g−1 at 1600 mA g−1), and excellent cycling stability (296 cycles at a limited capacity of 500 mA h g−1), which is much better than that with a bare δ-MnO2 catalyst. The achievement of excellent electrochemical performance is attributed to the highly efficient co-catalytic ability of δ-MnO2 and CeO2 and the desirable graphene-like architecture of the CeO2/δ-MnO2 catalyst, as well as the formation of the thin-layered discharge product Li2O2.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Chengzhong Xiong,Runzhang Tao,Jian Lu,Shilong Li,Dong Zou,Yuqing Sun,Wenheng Jing
Efficient recovery of Li + from lithium-ion batteries (LiBs), which also include Co 2+ , Ni 2+ , or Mn 2+ in the cathode material, remains a formidable challenge because the sizes and physicochemical properties of these ions. Composite lamellar membranes are emerging as highly ion-selective nanochannels with controllable interlayers. Herein, Li + /Co 2+ was precisely separated through two-dimensional MXene/δ-MnO 2 composite nanochannels under an electric field. The nanochannels were constructed on tubular ceramic membranes via hydroxyl crosslinking. The membrane layer spacing can be extended to 5.7 Å by electrostatic repulsion between MXene and δ-MnO 2 nanosheets, which is suitable for Li + /Co 2+ separation. Under an electric field of 2 mA cm −2 , Li + /Co 2+ was nearly completely separated, with a high Li + flux of 0.0094 mol m -2 h −1 , and the energy consumption was ∼0.315 kW h (mol Li + ) -1 . Similarly, near-complete separation of Li + /Ni 2+ and Li + /Mn 2+ can be achieved at a current density of 2 mA cm −2 . The transport of Li + in solution was accelerated under a positive electric field and by partial dehydration in the nanopores. Meanwhile, the zeta potential was distinctly more negative in the composite membranes than in individual MXene or δ-MnO 2 . Consequently, Co 2+ was rapidly adsorbed on the negatively charged membrane surface through electrostatic interactions and complexation, forming a positively charged Co 2+ layer that electrostatically repelled further Co 2+ adsorption, ultimately achieving near-complete separation of Co 2+ . Owing to their stable and robust structure, the MXene/δ-MnO 2 membranes maintained high separation efficiency in acidic solutions containing Li + and Co 2+ and remained stable over eight cycles (up to 14 h) of ion separation under an electric field. This approach can potentially realize 2D membrane composites for efficient ion separation in practical applications.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Yiheng Li,Tao Dong,Pingli Huang,Jian Ji,Haibao Huang
Airborne formaldehyde (HCHO) in indoor environments causes serious health problems and needs to be efficiently eliminated. However, the efficient and stable catalytic oxidation of HCHO can be hardly achieved at room temperature over transition metal oxides due to the limited exposure of active sites. Herein, δ-MnO 2 @GO catalysts were originally synthesized via a facile in situ growth of δ-MnO 2 on the trace graphene oxide (GO) substrate (1%) and stably exhibited nearly 100% HCHO elimination at room temperature. δ-MnO 2 @GO showed the unique 2D coralloid structure with uniformly dispersed δ-MnO 2 nanorod on planar-structured GO, which greatly enhanced the exposure of catalytic sites and mass transfer of reactants. The abundant surface reactive oxygen species (ROS) and hydroxyl (-OH) groups were rapidly generated from the activation of O 2 and surface-adsorbed water over highly exposed catalytic sites. The ROS and -OH groups cooperated well cooperated to maintain the exceptional catalytic activity and stability towards HCHO degradation. In-situ DRIFTS results showed that catalytic HCHO oxidation predominantly follows the Langmuir-Hinshelwood (L-H) mechanism over the δ-MnO 2 @GO. This study presents a simple yet effective strategy for maximizing exposure to catalytic active sites and rational design of efficient catalysts for indoor HCHO elimination.
研究领域:
环境科学
·
催化材料
✓ 已验证
DOI
高影响因子
SOLID STATE SCIENCES
·
2024
·
IF 3.4
Han Liu,Mingsong Zhang,Xiaoyun Liu,Zhihao Chai,Mai Li,Chunrui Wang,Jiale Wang
Periodically ordered δ-MnO 2 arrays of different periods have been fabricated by using polystyrene (PS) nanosphere lithography (NSL) combined with following hydrothermal growth. By choosing different precursors, δ-MnO 2 arrays with different alkali metals doping were obtained. It was observed that the K-doped δ-MnO 2 array of 500 nm period exhibited superior photocatalytic degradation performance of methylene blue (MB) under visible light irradiation relative to those of Na- or Mg-doped δ-MnO 2 arrays of 500 nm period, as well as K-doped δ-MnO 2 array of 800 nm period. The best performance of K-doped δ-MnO 2 array of 500 nm period can be firstly attributed to enhanced surface plasmon resonance (SPR) effect caused by alkali metal doping, where K-doped MnO 2 could provide more free electrons than those of Na- or Mg- doped MnO 2 . Furthermore, for the nanomaterials with SPR effect the surface plasmon polaritons (SPP) can change the propagation path of incident light to vertical direction after scattering on them. Since the MnO 2 array of 500 nm period possessed the distance between neighbor unites smaller than the wavelength of irradiation light, and thus the scattered light interfered with each other after the incident light was scattered by the MnO 2 unites. Then the electric field (E-field) intensities generated by SPR effect near each MnO 2 unit were elevated due to the interference effect. Therefore, our finding may provide a peculiar way to improve SPR-mediated photocatalytic performance of non-metallic materials by combination of doping and arrays fabrication of particular periods.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Xin Zhou,Qianwei Liang,Boqian Yang,Yuyu Chen,Yuanyuan Fang,Hanjin Luo,Yushan Liu
Compounding a single component with a specific function into a composite material that can fully exert synergy effects according to demand is the key to achieving the expected function and expanding emerging applications. Herein, anchoring δ -MnO 2 with strong oxidizing ability on the surface of Fe/Mg-MIL-88B with superior uptake ability for As(V) to form an amorphous nanocomposite with multiple functions for removing more toxic As(III). Due to special construction and rational design, the fabricated nanocomposite demonstrated an excellent As(III) removal performance over a very broad pH range of 3 to 10. Impressively, the adsorption efficiency of the obtained δ -MnO 2 @Fe/Mg-MIL-88B on As(III) is greatly improved, and the maximum adsorption capacity under laboratory conditions is as high as 221.04 mg/g in room temperature. Notably, the residual concentration of arsenic will drop below 10 μg/L, as long as the initial As(III) concentration is not higher than10 mg/L, which is very critical for further promotion. In general, the δ -MnO 2 @Fe/Mg-MIL-88B exhibits excellent promise in removing As(III) from sewage, and its applicability in practical complex water treatment deserves further study.
研究领域:
环境科学
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材料科学
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2021
·
IF 7.991
Lu Gan,Xingyu Fang,Lijie Xu,Linjie Wang,Ying Wu,Boren Dai,Wen He,Jiangtao Shi
In this study, kenaf carbon fiber (KCF) was prepared via direct pyrolysis of kenaf fiber. Afterwards, the prepared KCF was incorporated with δ-MnO 2 to prepare a series of δ-MnO 2 /KCF composites. The as-prepared composites were then used to degrade bisphenol A (BPA) in water via oxidative catalysis. Significantly enhanced oxidative capability of the δ-MnO 2 /KCF was realized, since the KCF could not only prevent δ-MnO 2 aggregation, but also facilitate electron transferring between δ-MnO 2 and BPA. The impacts of catalyst dosage, initial pollutant concentration, solution pH value, temperature, Mn 2+ and natural organic matters on the performance of the δ-MnO 2 /KCF composites were examined in detail. The results showed that 0.025 mM of BPA could be completely degraded within 10 min by 0.5 g/L of the catalyst at the pH value of 3.80. The subsequent LC-MS analysis results indicated that the δ-MnO 2 /KCF initiated BPA oxidative degradation and mineralization through capturing one electron from the BPA molecules and forming BPA radicals. Moreover, the as-prepared δ-MnO 2 /KCF composites also had promising long-time use stability and reusability. This study demonstrates a potentially applicable and sustainable biochar support which could enrich the performance of a catalyst for refractory organic contaminant removals in aqueous environment.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Fen Qiao,Wenjie Liu,Shuihua Yu,Qiaoling Zhang,Guodong Li,Huaqiang Chu
Mn 2 O 3 is and has received widespread attention in fields such as catalysis and energy storage. However, its poor conductivity limits its application as an electrode material for supercapacitors. Here, flower-like spheroidal δ-MnO 2 /Mn 2 O 3 composites composed of two-dimensional (2D) hierarchical nanosheets were prepared by the template method and a simple hydrothermal process. The growth process and electrochemical properties of δ-MnO 2 /Mn 2 O 3 composites were investigated by adjusting the concentration of KMnO 4 in the hydrothermal process. Since the introduction of δ-MnO 2 brings more pseudocapacitance to the composite, the synergistic effect between MnO 2 and Mn 2 O 3 reduces the interfacial resistance, and the unique nanosheet structure increases its specific surface area, which alleviates the volume expansion during the cycling, the δ-MnO 2 /Mn 2 O 3 composite electrode exhibits high specific capacitance (182 F g −1 at 0.5 A g −1 ), fast rate performance (74.2% capacitance retention at 5 A g −1 ), and excellent cyclic stability (90.1% capacitance retention after 5000 cycles at 5 A g −1 ). Symmetric supercapacitors assembled with δ-MnO 2 /Mn 2 O 3 electrodes also exhibit a high energy density of 9.1 Wh kg −1 . δ-MnO 2 /Mn 2 O 3 composites have greater application prospects in energy storage, and are expected to achieve further applications in lithium/sodium ion batteries, zinc ion batteries and other fields.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）