NANOTECHNOLOGY
·
2025
·Vol. 36
·期 14
·145601
·
IF 2.8
Xinyu Shi,Libo Deng,Lingna Sun,Qianling Zhang,Xiangzhong Ren,Yongliang Li
Manganese dioxide (MnO2) is recognized as a promising candidate for the oxygen evolution reaction (OER); however, its practical application is hindered by limited active sites and low electrical conductivity. Fluorine (F), known for its strong electron affinity and electronegativity, can modulate the surface electronic structure and physicochemical properties of catalysts. In this study, we synthesized MnO2 nanosheets and fluorine-doped MnO2 (F-MnO2) using simple hydrothermal and ion-exchange methods. We then assessed the influence of fluorine doping on the intrinsic OER activity and stability of these catalysts, as well as their underlying catalytic mechanisms. By manipulating the amount of fluorine introduced and the fluorination temperature, we explored the relationship between varying fluorine concentrations and OER performance. The experimental results show that F-MnO2 exhibits higher OER activity than pristine MnO2. At a current density of 10 mA cm–2, the overpotential required for F-MnO2 is merely 320 mV, substantially lower than that of pristine MnO2. This enhanced performance is ascribed to fluorine doping, which leads to an increased quantity of active Mn3+ centers and oxygen vacancies, along with an expanded electrochemically active surface area. Furthermore, F-MnO2 displays improved stability during the testing period. It maintains long-term stability for over 25 h, further corroborating the catalyst's excellent anti-oxidation and anti-corrosion properties in alkaline water electrolysis.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Runzhang Tao,Jian Lu,Shilong Li,Weihu Zhang,Zhongkai Shan,Yuqing Sun,Wenheng Jing
Designing stable, high-performance two-dimensional (2D) MnO 2 membranes for pervaporation (PV) desalination remains challenging. Herein, we present a photoinduced surface passivation strategy for the controlled growth of ultrathin single-layer δ-MnO 2 nanosheets, combined with layer-by-layer assembly to fabricate robust PV membranes. The e − / h + dual-path mechanism of photoinduced synthesis of MnO 2 was firstly proposed. Comprehensive structural characterizations and DFT simulations reveal that h + drives surface passivation stabilizes the thermodynamic configuration, while e − modulating growth kinetics to achieve narrow lateral size distributions of nanosheets. Moreover, the process generates Mn 3+ states (Mn (III) ≈ 49.96 %), abundant oxygen vacancies and surface hydroxyls, imparting exceptional hydrophilicity (water contact angle ≈ 10°) and enabling ultrafast water transport through the 2D channels during PV. The resulting MnO 2 membranes exhibit nearly complete salt rejection (99.9 %) and an impressive water flux of 36.53 kg m −2 h −1 in high-salinity feeds, outperforming state-of-the-art membranes. This work establishes photoinduced facet passivation as an effective route for precision-controlled growth of 2D nanosheets, opening promising avenues for next-generation PV membranes and other water purification technologies in harsh environments.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2026
·
IF 5.1
Jiaoyuan Lu,Xiaojun Tang,Huiting Bi
Compared with α-, β- and γ-MnO2, δ-MnO2 possesses a large interlayer spacing, abundant active sites and high compatibility with aqueous electrolytes. Due to these advantages, δ-MnO2 is considered a potential candidate for efficient aqueous zinc-ion battery and high-safety energy storage systems. Nevertheless, its structural instability and suboptimal electrical conductivity hinder it from being an ideal electrode material. In this study, a 3D conductive framework was fabricated by uniformly integrating δ-MnO2 and ultrathin rGO nanosheets through a simple freeze-drying process. The introduction of rGO endows the δ-MnO2/rGO composites with a unique “conductive network–dispersion support” structure. The as-constructed 3D architecture effectively overcomes the intrinsically low conductivity of δ-MnO2 and decreases the charge transfer resistance. Meanwhile, the porous framework enlarges the electrode–electrolyte contact area, accommodates the volume variation and lattice distortion during Zn2+ insertion/extraction, and thus maintains structural integrity upon long-term cycling. Consequently, the δ-MnO2/rGO electrode exhibits excellent cycling stability, with a maximum specific discharge capacity of 127.6 mAh g−1 at 1 A g−1, which remains at 82.1 mAh g−1 after 600 cycles. The specific capacity is obviously better than that of δ-MnO2 (63.2 mAh g−1 after 450 cycles).
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Ting Yang,You Zuo,Sijia Yan,Hang Zhang,Huanlin Zhang,Lei Ling,Baichuan He,Jiaqi Lu,Shu Cai
MnO 2 cathodes have been the focus of extensive research for aqueous zinc-ion batteries, owing to their inherent safety, environmental sustainability, and substantial theoretical capacity. However, manganese dissolution and slow kinetics during cycling lead to poor cycle stability and rate performance. In this study, a TiO 2 interphase was constructed on the δ-MnO 2 cathode by chemical liquid-phase deposition, which effectively inhibited the dissolution of manganese and improved the wettability of the electrode in the electrolyte, thus increasing the rate of ion transport at the interface, especially H + . Consequently, better cycle stability and faster electrochemical kinetics are produced for the δ-MnO 2 cathode, with a capacity retention of 87.6 % after 1000 cycles at 10 A g -1 and a specific capacity of 310 mAh g -1 at 0.2 A g -1 . This cost-effective and efficient method of constructing interphase to enhance electrode performance is scalable and provides insights into enhancing the performance of other manganese-based cathodes for aqueous zinc-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Shuaishuai Guo,Fangyuan Chang,Guowen Peng,Ping Cao,Wenjie Lu,Yanlu Lu,Jie Jiang,Qingyan Zhang,Qingyi Zeng
To meet the pressing demands of sustainable nuclear energy development and radioactive pollution mitigation, the development of high-efficiency adsorbents for uranium extraction from real wastewater is paramount. In this study, a MNP@NHCS adsorbent was engineered through a carrier-supported strategy involving in-situ growth of δ-MnO 2 nanoplates (MNP) on N-doped hollow carbon spheres (NHCS). Material characterization confirmed that NHCS suppresses δ-MnO 2 agglomeration and enhances the specific surface area to 218.22 m 2 /g (3.5-fold higher than pristine δ-MnO 2 62.28 m 2 /g). Batch experiments demonstrated exceptional performance: excellent U(VI) adsorption capacity (423.61 mg/g), outstanding selectivity ( K d = 1.9 × 10 5 mL/g), robust recyclability (>95 % removal over 8 adsorption-desorption cycles), and real wastewater breakthrough (95 % uranium recovery rate: 0.21 mg U(VI) / 100 mg ads.). Comprehensive characterization, multi-model fit analysis and in-situ zeta potential monitoring revealed that U(VI) capture follows a spontaneous, endothermic monolayer process driven by coordination-electrostatic synergy between Lewis acid-base sites (Mn-O, -OH, and -NH 2 ) and electrostatic attraction. This work provides an efficient, stable, and eco-friendly adsorbent for real wastewater treatment in the nuclear industry, advancing uranium resource recovery and sustainable nuclear energy development.
研究领域:
环境科学
·
材料科学
·
核工程
·
化学工程
·
吸附技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Mingrui Geng,Zhizhen Wang,Denghui Wang
Formaldehyde (HCHO), a ubiquitous indoor organic pollutant, severely threatens human health. Developing efficient and low-energy catalytic materials for room-temperature HCHO purification remains an urgent priority. In this work, Fe y MnO x catalysts were synthesized via a facile coprecipitation method. The Fe doping effectively modulated the morphology and crystallinity of δ-MnO 2 while inducing the formation of surface oxygen vacancies, thereby enhancing the capability to generate surface reactive oxygen species. Under a gas hourly space velocity (GHSV) of 150 L·g cat –1 ·h –1 , the catalyst achieved > 99 % removal efficiency for 100 ppm HCHO, along with exceptional stability. In situ DRIFTS reveals the influence of Fe doping on the catalytic reaction pathway for HCHO. This work demonstrates that the Fe doping strategy successfully optimizes the microstructure and surface chemical properties of δ-MnO 2 , resulting in outstanding room-temperature HCHO removal performance, providing valuable insights into defect engineering for optimizing transition metal oxide catalysts.
研究领域:
环境催化
·
材料科学
·
室内空气净化
·
过渡金属氧化物
·
缺陷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2026
·
IF 9.6
Haixiang Luo,Hui-Juan Zhang,Yiming Tao,Zhu He,Zhengyu Li,Yuhua Xue
δ-MnO 2 has been widely recognized as a promising cathode material for aqueous zinc-ion batteries (AZIBs) owing to its high theoretical specific capacity, low cost and environmental benignity. Nevertheless, its practical application is constrained by low electronic conductivity and structural instability. Herein, a class of Fe&Co dual-cations doping δ-MnO 2 (FCMO) is synthesized via a facile hydrothermal route, which effectively modulates the crystal structure and electrochemical properties of δ-MnO 2 . The nanoflower-like morphology of FCMO shortens the ion diffusion path and facilitates ion transport. Specifically, this dual-cations doping not only introduces oxygen vacancies to further promote electronic conductivity and structural stability, but also significantly expands the interlayer spacing to enhance Zn 2+ diffusion kinetics. Benefiting from these structural advantages, FCMO delivers a high specific capacity of 319.9 mAh·g −1 at a current density of 0.5 A·g −1 and an excellent rate performance of 100.1 mAh·g −1 at 2 A·g −1 . Moreover, it exhibits an outstanding cycling stability, retaining 94.7% of its capacity after 1000 cycles at 1 A·g −1 . This demonstrates that Fe&Co dual-cations doping strategy is an effective way to enhance the electrochemical performance of δ-MnO 2 , offering a valuable insight for the design and development of high-performance AZIBs.
✓ 已验证
DOI
PubMed
高影响因子
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL
·
2019
·Vol. 83
·期 2
·348-356
·
IF 1.997
Yurui Yang,Yuzhen Liang,Yajie You,Zecong Ding,Zhi Dang,Zhenqing Shi
Core Ideas Adsorption and desorption kinetics of As(V) on Fe and Mn oxide mixture was studied. A predictive kinetics model based on component additivity approach was developed. The kinetics model predicted the kinetic data of As(V) well for the mixed oxides. Ferrihydrite and δ-MnO2 controlled As(V) reaction kinetics differently. Arsenate [As(V)] soil contamination is a great concern worldwide because of its high toxicity, carcinogenicity, and mobility. The adsorption of As(V) on soil minerals such as ferrihydrite and δ-MnO 2 controls the transport and bioavailability of As(V) in the soil environment. A large number of studies have investigated the equilibrium and mechanisms of As(V) adsorption onto ferrihydrite and δ-MnO 2 individually. However, both ferrihydrite and δ-MnO 2 , commonly coexisting within soils has been overlooked and little information is available for the kinetics of As(V) adsorption and desorption in this mixed mineral system. Therefore, in this work, kinetics of As(V) adsorption and desorption onto ferrihydrite and δ-MnO 2 mixed minerals is studied using the stirred-flow method. A kinetics model for the mixed mineral system was developed using the component additivity approach, which incorporated the nonlinear binding of As(V) to both ferrihydrite and δ-MnO 2 simultaneously. The kinetics model successfully predicted the kinetics of As(V) adsorption and desorption in the mixed mineral system under varying solution chemistry conditions and properly accounted for the heterogeneity of the binding sites of both ferrihydrite and δ-MnO 2 . For As(V) adsorption kinetics, the ferrihydrite bidentate non-protonated sites (Fh-bi-np) played a dominant role, followed by the δ-MnO 2 binding sites and the ferrihydrite bidentate protonated sites (Fh-bi-p). After the 4-h desorption, As(V) was mainly retained on ferrihydrite binding sites. This study helps to quantitatively elucidate the kinetic behavior and mechanisms of As(V) in the Fe oxide and Mn oxide systems, thus enhancing our understanding of the fate and transport of As in soil environments.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
Catalysts
·
2026
·Vol. 16
·期 5
·454
·
IF 4.5
Xiudan Tao,Xiaohan Yang,Fufen Li,Yuqing He,Chenhui Liu,Zhengjun Li,Nianhua Dan
Oxygen vacancies play a crucial role in modulating the chemical and catalytic properties of metal oxide catalysts. Herein, quercetin was used as a green reducing agent to prepare Cu-doped MnO2(Cu-MnO2) composite catalysts with varying Cu doping levels via an ultrasonically assisted strategy. The structure-activity relationships were systematically investigated using XRD, Raman, XPS, H2-TPR, and O2-TPD. Benefiting from optimized surface lattice defects induced by an appropriate Cu doping level, the Cu-MnO2-2 sample, which exhibited the highest oxygen vacancy concentration, achieved a HCHO removal efficiency of 99.2% for 1 ppm HCHO at room temperature (25 °C) and 50% relative humidity within 30 min. The enrichment of Mn3+, Cu+, and surface-adsorbed oxygen species (Oads) further corroborated the increased oxygen vacancy density, indicating that moderate Cu doping effectively promotes electron transfer and oxygen activation. After five consecutive cycles, the HCHO conversion remained above 96%. Post-cycling characterizations (XRD, FTIR, EDS, and XPS) confirmed the excellent structural and chemical stability of the catalyst, with the Mn3+proportion and Cu+/Cu2+ratio well preserved. In situ DRIFTS analysis revealed that surface-adsorbed oxygen and oxygen-vacancy-activated reactive oxygen species (ROS) are key factors in the efficient HCHO oxidation over the green Cu-MnO2-2 catalyst, promoting rapid conversion of intermediates and ultimately generating CO2and H2O. This study provides a facile, low-cost, and green synthesis strategy for Cu-MnO2composite catalysts for indoor, room-temperature HCHO abatement, offering new insights into the design of other composite catalyst materials.
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9
Hanbo Shi,Nannan Zhang,Wei Guo,Tancheng Dong,Bihui Zhou,Lanlan Yu,Baojun Liu,Jincheng Mu
Birnessite-type δ-MnO 2 is a promising candidate for low-temperature NH 3 -SCR reaction owning to its excellent redox properties. However, its performance is severely hampered by the excessive oxidation state of Mn species, which induces strong NH 3 chemisorption and subsequent over-oxidation to NO x . Herein, phenylalanine-functionalized δ-MnO 2 nanosheets (MnO x -Phe) were developed, leveraging Phe's coordinating –NH 2 group to modulate surface properties of Mn species. The optimal MnO x -Phe-0.1 catalyst achieves ∼90% NO x conversion at 75 °C with a broad temperature window from 75 to 210 °C (GHSV = 50,000 h −1 ), representing a reaction rate 4.8 to 8.2 times greater than that of pure δ-MnO 2 . Additionally, the catalyst exhibits remarkable resistance against SO 2 and H 2 O. Comprehensive characterizations and density functional theory calculations reveal that Phe modification shifts down the d -band center of δ-MnO 2 from −1.22 eV to −2.78 eV, and attenuates the oxidation state of Mn species. This unique configuration suppresses the over-oxidation of NH 3 and weakens the interaction between catalyst and poisons, while promoting the activation of NH 3 to *NH 2 with a lower energy barrier, thus driving a desired Eley-Rideal pathway and endowing strong tolerance against SO 2 and H 2 O at low temperatures. This work provides a novel organic-inorganic hybrid strategy for designing robust low-temperature NH 3 -SCR catalysts with superior activity and poison resistance.
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2026
·Vol. 11
·期 2
·e03495
·
IF 2
You Li,Jinjian Lv,Yuning Sun,Lulu Zhan,Weiming Chen
MnO 2 is the most promising cathode material for aqueous zinc ion batteries (AZIBs), but poor conductivity, structural instability, and slow Zn 2+ kinetics in MnO 2 -based AZIBs still limit their practical use. Here, we present the introduction of graphene (Gr) into δ-MnO 2 with a layered structure designed for AZIBs to understand the effect of carbon materials on the electrochemical behavior of δ-MnO 2 cathodes. Nanoflower-structured δ-MnO 2 composites with graphene were fabricated via a one-step hydrothermal synthesis method. Owing to the incorporation of Gr, the cycling stability, rate performance, and reversibility of δ-MnO 2 have been significantly enhanced. The results show that at a current density of 0.5 A g − 1 , the δ-MnO 2 -1.5 h/Gr electrode exhibits a specific capacity of 125 mAh g − 1 with a capacity retention of 53.4% and a high Coulombic efficiency of 99.2%. At a higher current density of 1 A g − 1 , this electrode delivers a specific capacity of 142.5 mAh g − 1 after 1000 cycles, substantially higher than that of the δ-MnO 2 -1.5 h electrode. In addition, electrochemical data show that δ-MnO 2 -1.5 h/Gr possesses a higher pseudo-capacitance percentage and best rate performance. This study confirms that incorporating carbon materials is an effective strategy for enhancing the energy storage performance of δ-MnO 2 in AZIBs and understanding its charge-discharge mechanism. Graphical The incorporation of graphene (Gr) improved the cycling stability, rate capability, and reversibility of δ-MnO2. δ-MnO2/Gr possessed higher ion diffusion rates and higher pseudo-capacitance occupancy, and exhibited the best rate performance. Thus, improving the zinc storage performance and cycling stability of zinc ion water batteries.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2025
·
IF 9.8
Boyou Hu,Haiyang Li,Menglei Wang,Zhiqiang Rao,Liqing Hao,Xuan Yu,Meng Zhang
The development of high-performance aqueous zinc-ion batteries (AZIBs) is promising for energy storage applications, yet challenges persist due to excessive pseudo-capacitance, structural instability and low conductivity of cathode materials. In this study, an Ag-doped mesoporous δ-MnO 2 nanocomposite (Ag–MnO 2 ) was rationally designed as a high-specific-capacity cathode material for AZIBs. Intercalated Ag + stabilize the layered δ-MnO 2 framework and expand ion diffusion channels, while surface-anchored Ag nanoparticles enhance electrical conductivity, optimize pseudo-capacitance and enhance reaction kinetics of δ-MnO 2 . Electrochemical tests reveal that Ag–MnO 2 delivers an amazing specific capacity of 491.7 mAh g −1 , a high power density of 133.1 W kg −1 and a superb energy density of 660.0 Wh kg −1 at 0.1 A g −1 , significantly outperforming pristine δ-MnO 2 , an approximate power density of 135.6 W kg −1 and a poor energy density of 457.1 Wh kg −1 at 0.1 A g −1 . Furthermore, Ag–MnO 2 exhibits exceptional cycling stability, retaining 95.6 % capacity after 800 cycles at 1.0 A g −1 . Ex-situ X-ray diffraction and X-ray photoelectron spectroscopy analyses elucidate the energy storage mechanism of Ag–MnO 2 in AZIBs. A flexible pouch cell fabricated with Ag–MnO 2 demonstrates stable operation under bending conditions, which holds enormous potential in flexible battery applications, achieving high electrochemical performance of 470.3 mAh g −1 , 112.2 W kg −1 and 610.7 Wh kg −1 at 0.1 A g −1 . This work provides a scalable strategy for designing high-performance AZIBs cathodes and offers insights into material regulation for overcoming energy storage limitations, applicable to broader energy storage systems.
✓ 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）