CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Junjun Tang,Shuan Ma,Yu Jiang,Lufeng Yang,Jie Chen,Xuemin Yan,Bohong Chen,Zhenxiong Huang
The inferior cycling stability of MnO 2 -based cathodes, resulting from Mn dissolution and crystal structure transition during Zn-ion insertion/extraction, poses a significant challenge hindering their widespread adoption in aqueous zinc-ion batteries (AZIBs). To mitigate these issues, we propose an approach involving the incorporation of small organic molecules (methylformamide, dimethylformamide, and formamide) to modify the crystalline structure of MnO 2 . These molecules, characterized by their low orbital energy levels, facilitate the creation of energetically equivalent electron transfer pathways with the unoccupied e g orbitals in Mn 4+ , as evidenced by the DFT calculations. Furthermore, they modulate the electron cloud density of Mn-O and introduce structural disorder in the MnO 2 crystalline lattice, thereby greatly enhancing the structural stability of the Mn-based cathode. In AZIBs tests, the MnO 2 /methylformamide (MO/NMF) cathode demonstrates a remarkable reversible specific capacity exceeding 270 mAh g -1 at 1 A g -1 and exceptional durability, exhibiting negligible capacity degradation after 2000 cycles at 3 A g -1 . In-situ X-ray diffraction, neutron powder diffraction and high-angle annular dark-field scanning transmission electron microscopy analyses confirm the structure stability of MO/NMF during Zn-ion insertion/extraction, attributed to the NMF modification. Additionally, the electrochemical data indicate that modifications with dimethyl formamide and formamide also positively impact the electrochemical performance of the MnO 2 cathode. This study offers valuable insights for the development of high-performance Mn-based cathodes.
研究领域:
材料科学
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电化学
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能源存储
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DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 16
·2856
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IF 5.719
Anis Ur Rahman,Nighat Zarshad,Wu Jianghua,Muslim Shah,Sana Ullah,Guigen Li,Muhammad Tariq,Asad Ali
Electrochemical energy storage devices are ubiquitous for personal electronics, electric vehicles, smart grids, and future clean energy demand. SCs are EES devices with excellent power density and superior cycling ability. Herein, we focused on the fabrication and DFT calculations of Na3-δ-MnO2nanocomposite, which has layered MnO2redox-active sites, supported on carbon cloth. MnO2has two-dimensional diffusion channels and is not labile to structural changes during intercalation; therefore, it is considered the best substrate for intercalation. Cation pre-intercalation has proven to be an effective way of increasing inter-layered spacing, optimizing the crystal structure, and improving the relevant electrochemical behavior of asymmetric aqueous supercapacitors. We successfully established Na+pre-intercalated δ-MnO2nanosheets on carbon cloth via one-pot hydrothermal synthesis. As a cathode, our prepared material exhibited an extended potential window of 0–1.4 V with a remarkable specific capacitance of 546 F g−1(300 F g−1at 50 A g−1). Moreover, when this cathode was accompanied by an N-AC anode in an asymmetric aqueous supercapacitor, it illustrated exceptional performance (64 Wh kg−1at a power density of 1225 W kg−1) and incomparable potential window of 2.4 V and 83% capacitance retention over 10,000 cycles with a great Columbic efficiency.Keywords:manganese oxide;pre-intercalation;specific capacitance;wide potential window;asymmetric aqueous supercapacitor;DFT calculation
研究领域:
材料科学
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电化学
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理论计算
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PubMed
高影响因子
Journal of Energy Storage
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2026
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IF 10.7
Chuang Wang,Lingzhuo Yang,Jinxiang Long,Tao Xie,Chuang Li,Yanhong Xiang,Xianming Wu,Xianwen Wu
With the growing demand for sustainable energy, aqueous zinc-ion batteries (AZIBs) have attracted considerable attention as an emerging energy-storage technology owing to their low cost and high safety. However, one of the most widely used cathode materials of manganese dioxide (MnO 2 ) for AZIBs suffers from unstable electrochemical performance of sluggish zinc-ion diffusion and gradual structural degradation. To solve these problems, we propose a simple in-situ pre-intercalation strategy to construct lysine-functionalized δ-MnO 2 (Lys-MnO 2 ), thereby reinforcing the structural stability and boosting the electrochemical performance of MnO 2 . XRD and HRTEM characterizations, combined with GITT and EIS analyses, demonstrate that lysine molecules effectively increase the interlayer spacing of MnO 2 and facilitate zinc-ion diffusion. Electrochemical tests show that the Lys-MnO 2 cathode exhibits the markedly enhanced cycling performance. It maintains a reversible capacity of over 274 mAh g −1 after 100 cycles at 0.2 A g −1 and retains 92.7% of its capacity even after 900 cycles at 1 A g −1 , superior to those of the pristine MnO 2 cathode. This work provides an innovative route for the development of high-performance and long-lifespan manganese-based cathode materials for AZIBs.
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高影响因子
Materials
·
2025
·Vol. 18
·期 19
·4632
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IF 3.2
Fan Zhang,Haotian Yu,Qiongyue Zhang,Yahao Wang,Haodong Ren,Huirong Liang,Jinrui Li,Yuanyuan Feng,Bin Zhao,Xiaogang Han
Aqueous zinc-ion batteries (ZIBs) have emerged as a promising candidate for large-scale energy storage due to their inherent safety, low cost, and environmental friendliness. However, manganese dioxide (MnO2)-based cathodes, which are widely studied for ZIBs owing to their high theoretical capacity and low cost, face severe capacity fading issues that hinder the commercialization of ZIBs. This performance degradation mainly stems from the weak van der Waals forces between MnO2layers leading to structural collapse during repeated Zn2+insertion and extraction; it is also exacerbated by irreversible Mn dissolution via Mn3+disproportionation that depletes active materials, and further aggravated by dynamic electrolyte pH fluctuations promoting insulating zinc hydroxide sulfate (ZHS) formation to block ion diffusion channels. To address these interconnected challenges, in this study, a synergistic strategy was developed combining crystal engineering and pH buffer regulation. We synthesized three MnO2polymorphs (α-, δ-, γ-MnO2), identified δ-MnO2with flower-like microspheres as optimal, and introduced sodium dihydrogen phosphate (NaH2PO4) as a pH buffer (stabilizing pH at 2.8 ± 0.2). The modified electrolyte improved δ-MnO2wettability (contact angle of 17.8° in NaH2PO4-modified electrolyte vs. 26.1° in base electrolyte) and reduced charge transfer resistance (Rct = 78.17 Ω), enabling the optimized cathode to retain 117.25 mAh g−1(82.16% retention) after 2500 cycles at 1 A g−1. This work provides an effective strategy for stable MnO2-based ZIBs, promoting their application in renewable energy storage.
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高影响因子
Journal of Energy Storage
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2024
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IF 8.9
Shakeel Abbas,Tanveer H Bokhari,Amina Zafar,Saqib Javed,Shafqat Karim,Hongyu Sun,Shafqat Hussain,Atia Khalid,Yanlong Yu,Rao Tahir Ali Khan,Inayat Ullah,Amjad Nisar,Mashkoor Ahmad
In this work, Zn-doped δ-MnO 2 (ZnMO) flower-like nanostructures on carbon fibers are synthesized by one-pot hydrothermal method . It is found that insertion of Zn ions induces oxygen vacancy defects, increase in active sites and conductivity of δ-MnO 2 (MO) structure. These features making ZnMO structure an excellent candidate for the fabrication of electrode material for supercapacitors . It has been revealed that ZnMO@CC electrode delivered an enhanced specific capacitance of 667 F g −1 at a current density of 1 A g −1 as compared to the pristine δ-MnO 2 and previously reported nanostructures . The developed asymmetric coin cell supercapacitor (ZnMO//AC) obtained a specific capacitance of 116 F g −1 at 1 A g −1 and achieved an outstanding energy density of 71.5 Wh kg −1 at a power density of 1067.1 W kg −1 . Moreover, the device retains its initial capacitance of 92 % after 8000 cycles at 8 A g −1 . These results suggest that ZnMO could be an emerging electrode material for the fabrication of high-performance supercapacitors for practical applications. This research hunts for new visions for the preparation of MnO 2 -based material by doping strategy for energy storage applications, especially supercapacitor.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
Nano Research
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2023
·Vol. 17
·期 3
·1173-1181
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IF 9.9
Liu Kang,Wu Tong,Xu Luying,Zhang Zhuangzhuang,Liu Zhiyu,Wang Longfei,Wang Zhong Lin
The separation of photogenerated electron–hole pairs is vitally important for photocatalysis, which can be effectively promoted by polarization field. However, it only manifests in piezoelectric/pyroelectric/ferroelectric materials that have a non-centrosymmetric structure. Here, we demonstrate that the polarization enhanced photocatalysis (with wide spectra from ultraviolet (UV) light to visible light) can be achieved in centrosymmetric semiconductors, such as δ-MnO 2 and TiO 2 nanosheets integrated nanoflowers, by using the strain-gradient-induced flexoelectric polarization that is always overlooked in polarization-enhanced catalysis. Under ultrasonic and illumination excitation, the organic pollutants (methylene blue (MB), etc.) can be effectively degraded within 30 min with excellent stability and repeatability. Compared with photocatalysis, the flexo-photocatalytic performance of above centrosymmetric semiconductors is substantially increased by 85%. Moreover, the factors related to flexo-photocatalysis such as material morphology, mechanical stimuli source, and adsorption are explored to deeply understand the mechanism of flexo-photocatalysis. This work opens up a way for high-performance photocatalysis in centrosymmetric semiconductors.
研究领域:
光催化
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材料科学
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半导体物理
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纳米技术
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环境科学
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2026
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IF 9.6
Cheng Han,Zhe Zhang,Yin Wei,Lanlan Liang,Xinao Zhao,Danna Yang,Zhongze Cui,Chuanliang Zhao,Liwei Yang
PVP-assisted synthesis enabled in-situ δ-MnO 2 -to-MnOOH reconstruction. • MnOOH/δ-MnO 2 interfaces enhanced PMS adsorption and electron transfer. • Surface-bound PMS* species enabled selective ETP-dominated TC oxidation. • The system maintained high TC removal in real lake water and groundwater. • The catalytic membrane achieved stable TC removal at low PMS dosage. Developing non-radical peroxymonosulfate (PMS) activation pathways that resist interference from complex water matrices remains challenging for the treatment of emerging contaminants in practical applications. A polyvinyl pyrrolidone-assisted hydrothermal strategy was therefore developed to induce the partial in - situ reconstruction of δ-MnO 2 into MnOOH. The resulting MnOOH/δ-MnO 2 interface directed PMS activation toward an electron transfer process (ETP) for tetracycline (TC) removal. The catalyst achieved nearly complete TC removal within 30 min and maintained high activity under complex water matrix conditions. Experimental results and density functional theory (DFT) analysis revealed that the MnOOH/δ-MnO 2 composite interface strengthened PMS adsorption and promoted interfacial charge redistribution. These effects facilitated electron transfer during TC oxidation. Surface-bound PMS* species on the MnOOH/δ-MnO 2 interface acted as electron-accepting centers, steering TC oxidation toward an ETP-dominated non-radical pathway. The MnOOH/δ-MnO 2 catalytic membrane maintained above 98% TC removal in real water matrices under continuous-flow conditions at only 0.2 mM PMS. These results demonstrate the promising practical applicability of the system. Life cycle assessment further indicated a comparatively low environmental burden for the MnOOH/δ-MnO 2 /PMS system. These findings provide a mechanistic basis for designing manganese oxide/oxyhydroxide catalysts through polymer-induced interfacial reconstruction and offer a practical strategy for ETP-dominated PMS activation in complex water treatment Download: Download high-res image (222KB) Download: Download full-size image
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2026
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IF 12.5
Shuo Li,Jing Zhu,Longkun Wu,Yasong Han,Ningning Zhao,Bin Li,Shaaban M. Shaaban,Lei Dai,Ling Wang,Zhangxing He
Introduced Co 2+ increases the structural stability of δ-MnO 2 and enlarges the interlayer spacing, promoting ion diffusion. • δ-MnO 2 @Co/TCT further improves the electrical conductivity, ameliorates the agglomeration problem and increases the electrochemical reaction active area. • Synergistic improvement of electrochemical performance through the strategy of ion doping and introduction of conductive materials, Zn//δ-MnO 2 @Co/TCT full cell with 1000 stable cycles at 1.5 A g -1 . δ-MnO 2 is considered a highly promising cathode material for aqueous zinc-ion batteries (AZIBs). However, its practical application is hindered by two critical issues: delayed transport kinetics and insufficient structural stability. Therefore, a synergistic strategy involving Co 2+ doping and composite coating with Ti 3 C 2 T x MXene (TCT) nanosheets was designed and implemented to achieve effective doping of the δ-MnO 2 lattice with Co and to ensure uniform loading of the active component onto the TCT substrate surface, ultimately leading to the successful fabrication of the δ-MnO 2 @Co/TCT composite material. First, the incorporation of Co 2+ as interlayer pillars effectively widens the interlayer spacing of δ-MnO 2 , thereby enhancing its structural stability and enabling faster ion embedding/de-embedding. Second, the TCT conductive substrate effectively mitigates the agglomeration of δ-MnO₂@Co, significantly increasing the electrochemical reaction area. Benefiting from the unique composite structure design, the Zn//δ-MnO 2 @Co/TCT full cell exhibits significantly optimized electrochemical performance. The assembled cell delivers a high specific capacity of 239.5 mAh g −1 at 0.5 A g −1 , and maintains outstanding cycling stability over 1000 cycles at 1.5 A g −1 . Result indicates that comprehensive performance of cathode materials can be effectively enhanced by multilevel structural synergistic design, providing a feasible technological pathway for development of high-performance AZIBs.
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高影响因子
Small Methods
·
2022
·Vol. 6
·期 12
·2201142
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IF 15.367
Ce Qiu,Jia Liu,Hanghui Liu,Xiaohui Zhu,Liang Xue,Shuang Li,Mingzhu Ni,Yang Zhao,Tong Wang,Serguei V. Savilov,Sergey M. Aldoshin,Hui Xia
Although birnessite-type manganese dioxide (δ-MnO 2 ) with a large interlayer spacing (≈7 Å) is a promising cathode candidate for aqueous Zn/MnO 2 batteries, the poor structural stability associated with Zn 2+ intercalation/deintercalation limits its further practical application. Herein, δ-MnO 2 ultrathin nanosheets are coupled with reduced graphene oxide (rGO) via van der Waals (vdW) self-assembly in a vacuum freeze-drying process. It is interesting to find that the presence of vdW interaction between δ-MnO 2 and rGO can effectively suppress the layered-to-spinel phase transition in δ-MnO 2 during cycling. As a result, the coupled δ-MnO 2 /rGO hybrid cathode with a sandwich-like heterostructure exhibits remarkable cycle performance with 80.1% capacity retained after 3000 cycles at 2.0 A g −1 . The first principle calculations demonstrate that the strong interfacial interaction between δ-MnO 2 and rGO results in improved electron transfer and strengthened layered structure for δ-MnO 2 . This work establishes a viable strategy to mitigate the adverse layered-to-spinel phase transition in layered manganese oxide in aqueous energy storage systems.
研究领域:
材料科学
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电化学
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能源存储
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产品关联
DOI
PubMed
高影响因子
RARE METALS
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2023
·
IF 8.8
Zhuang Wen-Chang,Zhang Hai-Yue,Chen Zhen-Yang,Cheng Wen-Jing,Na Wei-Dan,Li Zhao,Tian Lin
Paper-based sensing platform is a point of need analytical toolkit for safety testing. However, the sensitivity, specificity, and simplicity are still challenging. Herein, we report a novel strategy (Au/δ-MnO 2 hollow nanosphere and 3,3′,5,5′-tetramethylbenzidine (TMB) induced test strips for signal-on detection) that can be utilized for hexavalent chromium (Cr 6+ ) detection. Interestingly, Cr 6+ (CrO 4 2− ) as a smart switch can remarkably enhance the oxidase-like activity of Au/δ-MnO 2 hollow nanosphere. The presence of Cr 6+ can regulate the surface electronic redistribution of Au/δ-MnO 2 and adjust the geometric configuration, which leads to the improvement in oxidase-like activity of Au/δ-MnO 2 . As a proof-of-concept application, a visual paper-based sensing platform of Cr 6+ along with quantitative analysis by the test strips was successfully constructed. This paper-based sensing platform exhibits a linear range with excellent selectivity for other interfering substances and lower limit of detection of 0.09 μmol·L −1 , providing a promising toolkit at-home Cr 6+ measurement and environmental monitoring. Graphical abstract
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2025
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IF 7.7
Shuwen Zhu,Huiqing Fan,Lin Lei,Yongbo Fan,Weijia Wang
Developing triethylamine (TEA) sensors using metal oxide semiconductors (MOS) presents challenges such as achieving high sensitivity, low operating temperatures, and reliable detection of trace TEA. In this study, a novel two-step solvothermal synthesis strategy was developed for the sequential fabrication of δ-MnO 2 nanosheets and δ-MnO 2 /WO 3 (WMn) heterojunction composites. The resulting WMn heterostructure features a unique morphology, where δ-MnO 2 nanosheets are encapsulated within a WO 3 matrix, forming well-defined layered interfaces and abundant active sites. This tailored structure significantly enhances the TEA sensing performance. In particularly, WMn1 sensor achieves an ultrahigh response of 515.37 to 20 ppm TEA at 140 °C. The sensor also exhibits an exceptionally low detection limit of 15.91 ppb, along with rapid response/recovery kinetics and long-term stability. The superior performance is attributed to the formation of n–p heterojunction and the synergistic effects of electronic and chemical sensitization, which optimize charge carrier dynamics, reduce interfacial resistance, and enhance surface reactivity. By focusing on interface engineering in heterojunction-based gas sensors, this study contributes to the strategic design of high-performance sensing materials, with potential applications in environmental monitoring and industrial safety.
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高影响因子
FUEL
·
2023
·
IF 7.4
Xu Wu,Heqin Guo,Litao Jia,Yong Xiao,Bo Hou,Yongxiang Gao,Debao Li
δ-MnO 2 shows potential application in furfural base-free oxidation to furoic acid. While, its catalytic mechanism was unclear, which limited the further improvement of the catalytic activity . Therefore, three δ crystal MnO 2 with different hydroxyl and active oxygen species concentrations were prepared and applied in the furfural oxidation reaction. IR, Furfural-IR, O 2 -TPD, H 2 O- 18 O 2 -TPD, and XPS techniques characterized the hydroxyl and active oxygen species. The results show that the hydroxyl group on δ-MnO 2 is important in absorbing and attacking furfural to form geminal diol intermediate. Moreover, two types of oxygen species O -OH and O ads originating from the surface hydroxyl and the strongly adsorbed gas-phase O 2 , respectively, play an essential role in defhydrogenating geminal diol to furoic acid. Most importantly, the hydroxyl, O -OH , and O ads consumed on δ-MnO 2 can be reconstructed under reaction conditions. Among the three δ crystal MnO 2 , δ-MnO 2 , with the most abundant hydroxyl and active oxygen species, exhibited the best catalytic performance with 99.53% furfural conversion and nearly 100% furoic acid selectivity. This work identifies the function of hydroxyl and active oxygen species on δ-MnO 2 in furfural oxidation reaction, guiding the design of a non-noble metal catalyst for furoic acid synthesis under base-free conditions.
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高影响因子
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