RSC Advances
·
2021
·Vol. 11
·期 56
·35280-35286
·
IF 3.361
Jingliang Xu,Xinhang Hu,Md Asraful Alam,Gul Muhammad,Yongkun Lv,Minghai Wang,Chenjie Zhu,Wenlong Xiong
Zn/MnO2 batteries, one of the most widely studied rechargeable aqueous zinc-ion batteries, suffer from poor cyclability because the structure of MnO2 is labile with cycling. Herein, the structural stability of α-MnO2 is enhanced by simultaneous Al3+ doping and lignin coating during the formation of α-MnO2 crystals in a hydrothermal process. Al3+ enters the [MnO6] octahedron accompanied by producing oxygen vacancies, and lignin further stabilizes the doped Al3+ via strong interaction in the prepared material, Al-doped α-MnO2 coated by lignin (L + Al@α-MnO2). Meanwhile, the conductivity of L + Al@α-MnO2 improves due to Al3+ doping, and the surface area of L + Al@α-MnO2 increases because of the production of nanorod structures after Al3+ doping and lignin coating. Compared with the reference α-MnO2 cathode, the L + Al@α-MnO2 cathode achieves superior performance with durably high reversible capacity (∼180 mA h g−1 at 1.5 A g−1) and good cycle stability. In addition, ex situ X-ray diffraction characterization of the cathode at different voltages in the first cycle is employed to study the related mechanism on improving battery performance. This study may provide ideas of designing advanced cathode materials for other aqueous metal-ion batteries.
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
DIAMOND AND RELATED MATERIALS
·
2022
·
IF 3.806
Jiwei Xie,Guijing Liu,Jia Sun,Rundou Zheng,Wenwen Zhao,Tongtong Chu,He Lin,Yanbin Xu,Shanmin Gao,Zhuyin Sui
MnO 2 as the cathode material of Zinc-ion batteries (ZIBs) has attracted great attention. In order to further improve the performance of ZIBs, MnO 2 hollow nanorobs and carbon nanotubes (CNTs) are compounded to obtain α-MnO 2 /CNTs nanocomposites in which robs and tubes are entangled with each other and present the cross-linked reticular structure. This structure of α-MnO 2 /CNTs electrode is obtained through hydrothermal strategy and provides large space for the volume variation of MnO 2 during the charge and discharge process. The α-MnO 2 /CNTs composite displays an excellent initial discharge capacity of 302 mAh·g −1 at 100 mA·g −1 , and keeps 116 mAh·g −1 at 2000 mA·g −1 (78.4% retention after 2000 cycles). This composite provides a new way for the further application of ZIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Yuejie Li,Yan Chen,Xinyue Wang,Khalil Md Ibrahim,Guowen Wang,Xinxin Zhang,Hongchao Ma
Recently, employing photoelectrocatalysis (PEC) strategy to eliminate environmental impact and hazards of hard-to-handle antibiotics such as sulfamethoxazole (SMX) has been given increasing attention. Herein, a “honeycomb” heterostructured α-MnO 2 nanowire/NiCo 2 O 4 hollow nanocages PEC catalyst is fabricated by using a continuous assembly process as following: (1) construction of α-MnO 2 nanowire carrier, (2) surface adhesion of ZIF-67, and (3) Co/Ni ion exchange. The as-synthesized Ti/α-MnO₂@NiCo₂O₄ demonstrated excellent PEC performance for degrading SMX, as compared with that of α-MnO 2 , α-MnO 2 @ZIF-67. Especially, the optimized Ti/α-MnO₂@NiCo₂O₄-30 showed removal rate of 98.2 % for SMX in 30 min, outstanding durability (~8000 s), and tolerable reusability (the removal rate can still reach 76.5 % for SMX after five cycles). The improvement of PEC performance for Ti/α-MnO₂@NiCo₂O₄ can be attributed to that the unique porous structure formed numerous electrochemically active sites, and the α-MnO₂ nanowire as common channel for charge transfer promoted the migration of induced carriers. The DFT calculation indicated that a II-scheme heterojunction can be formed over the α-MnO 2 @NiCo 2 O 4 composite, which can effectively inhibit the recombination of induced carriers, facilitate the degradation process. This work provides a valuable approach for constructing nanohybrids with targeted functionalities, opening new possibilities for the application of nanomaterials in wastewater treatment.
研究领域:
环境科学
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纳米材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2025
·
IF 3.7
Kang Liu,Shuang Luo,Jianying Liang,Pengfei Xu,Jinglv Feng,Shumin Qin,Jien Li
Graphical A hydrothermal process is used for co-doping Mo and Zn into tunnel-structured MnO 2 (MZMO), enhancing its ion diffusion kinetics and electrical conductivity by introducing impurity energy levels and generating oxygen vacancies. This co-doping strategy also stabilizes the MnO 2 framework, enabling the MZMO cathode to achieve exceptional capacity, highly reversible H + /Zn 2+ co-intercalation, and prolonged cycle life. To address the rising demand for eco-friendly and efficient energy storage devices, rechargeable aqueous zinc ion batteries (AZIBs) are emerging as a promising candidate for large-scale energy storage. α-MnO 2 has attracted extensive attention for its open channels and exceptional Zn 2+ storage capacity. However, the electrochemical performance of α-MnO 2 is significantly hindered by severe structural collapse and sluggish reaction kinetics. Herein, we propose a simple hydrothermal approach for co-doping Mo and Zn into tunnel-structured MnO 2 (MZMO). The ion diffusion kinetics of MZMO are optimized due to ameliorated electrical conductivity by doped cations and introduced oxygen vacancies within the MnO 2 lattice. Moreover, Mo and Zn co-doping stabilizes the MnO 2 framework, significantly enhancing its electrochemical performance during prolonged cycling. Charge storage mechanism analysis further validates the extraordinary stability of the MZMO phase structure during the Zn 2+ /H + co-intercalation and deintercalation. The MZMO cathode demonstrates rapid and reversible Zn 2+ storage, with a high capacity of 395 mAh g −1 at 0.2 A g −1 , and the capacity remains at 136 mAh g −1 after 1000 cycles at 2 A g −1 . This study demonstrates Mo and Zn co-doping is an effective strategy to enhance the electrochemical performance of MnO 2 , offering valuable insights for developing other promising cathodes for AZIBs.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Progress in Natural Science-Materials International
·
2023
·
IF 4.7
Siyi Wang,Yuxuan Bai,Zhixiong Zhang,Chengde Xie,Wenhui Song,Chen Wang,Zhuoyu Ji,Jianjun Wang
In this study, the one-dimensional nanomaterial α-MnO 2 @ZIF-8 was satisfactorily fabricated using a simple hydrothermal method by modifying ZIF-8 on α-MnO 2 nanowires for high-performance extraction of U(VI) out of water solution. The experimental data indicated that the adsorption of U(VI) on α-MnO 2 @ZIF-8 was intensely dependent on solution pH but not on ionic strength . The maximum adsorption of U(VI) on α-MnO 2 @ZIF-8 at pH = 5.0 and T = 298 K was 802.36 mg/g, substantially higher than the adsorption on α-MnO 2 (22.32 mg/g) or ZIF-8(551.31 mg/g) under the same conditions, indicating that the performance of the modified α-MnO 2 was greatly enhanced. Attaining adsorption equilibrium within 45 min, the analytical kinetic process of α-MnO 2 @ZIF-8 indicated that its adsorption on U(VI) was monolayer chemisorption . The adsorption experiments and XPS analyzed the possible adsorption mechanism of U(VI) in the reaction with α-MnO 2 @ZIF-8 during the adsorption process , namely intra-sphere surface complexation, chemisorption and electrostatic interaction . The simple preparation and high removal efficiency of α-MnO 2 @ZIF-8 indicated that this adsorbent had good prospects for application in wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Linhao Yu,Hong Chen,Zhe Wen,Mengmeng Jin,Zewei Ma,Xueli Ma,Yushuai Sang,Mengmeng Chen,Yongdan Li
Selective oxidation of 5-hydroxymethylfurfural (HMF) to 2, 5-diformylfuran (DFF) with molecular oxygen is realized with an α-MnO 2 catalyst under mild conditions. In this work, α-MnO 2 exhibited the best performance among the samples examined. Meanwhile, solvent shows a significant effect on the product selectivity and isopropanol is found good for improving the selectivity of DFF. 93.2 % conversion of HMF was achieved at 140 °C for 4 h with 84.3 % selectivity of DFF. Moreover, α-MnO 2 catalyst keeps good reusability in recycling for five times. The reaction pathway indicated that the lattice oxygen species on α-MnO 2 is involved in the selective oxidation of hydroxyl group in HMF molecule.
研究领域:
催化化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Le Thi Thao,To Van Nguyen,Van Quy Nguyen,Ngoc Man Phan,Ki Jae Kim,Nguyen Nhat Huy,Nguyen Trung Dung
Wastewater containing an azo dye Orange G (OG) causes massive environmental pollution , thus it is critical to develop a highly effective, environmental-friendly, and reusable catalyst in peroxymonosulfate (PMS) activation for OG degradation. In this work, we successfully applied a magnetic MnFe 2 O 4 /α-MnO 2 hybrid fabricated by a simple hydrothermal method for OG removal in water. The characteristics of the hybrid were investigated by X-ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy , Brunauer–Emmett–Teller method, vibrating sample magnetometry, electron paramagnetic resonance, thermogravimetric analysis , and X-ray photoelectron spectroscopy. The effects of operational parameters (i.e., catalytic system, catalytic dose, solution pH, and temperature) were investigated. The results exhibited that 96.8% of OG degradation was obtained with MnFe 2 O 4 /α-MnO 2 (1:9)/PMS system in 30 min regardless of solution pH changes. Furthermore, the possible reaction mechanism of the coupling system was proposed, and the degradation intermediates of OG were identified by mass spectroscopy . The radical quenching experiments and EPR tests demonstrated that SO 4 • ̶ , O 2 • ̶ , and 1 O 2 were the primary reactive oxygen species responsible for the OG degradation. The hybrid also displayed unusual stability with less than 30% loss in the OG removal after four sequential cycles. Overall, magnetic MnFe 2 O 4 /α-MnO 2 hybrid could be used as a high potential activator of PMS to remove orange G and maybe other dyes from wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Jing Deng,Yongjian Ge,Chaoqun Tan,Hongyu Wang,Qingsong Li,Shiqing Zhou,Kejia Zhang
Nanoscale α-MnO 2 with different morphologies (nanoparticles, nanoflowers and nanorods) were synthesized via a facile hydrothermal method and tested in peroxymonosulfate (PMS) activation for ciprofloxacin (CIP) degradation. The catalytic activity of α-MnO 2 mainly relied on the specific surface area and crystallinity, and followed the order of α-MnO 2 nanoflowers > α-MnO 2 nanorods > α-MnO 2 nanoparticles > commercial MnO 2 . Acidic condition was more beneficial to CIP removal than neutral condition, and the degradation would be greatly accelerated in alkaline circumstance. The introduction of chloride and bicarbonate displayed concentration-dependent dual effect. The presence of natural organic matter (NOM) exerted the detrimental effect on CIP degradation. Eleven oxidation products were identified by UPLC–MS/MS and the changes of their concentrations were monitored, five products showed monotonous uptrend while four intermediates present monotonous downtrend once they were generated. Piperazine ring cleavage, hydroxylation and F/OH substitution were found to be the important oxidation pathways. The acute toxicity of resulted solution gradually decreased with the lapse of time, and higher PMS concentration favored the detoxification. The CIP removal in α-MnO 2 /PMS process was also efficient under the actual water background, which was testified by the results of fluorescence excitation-emission matrix (EEM).
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Ping Li,Shujuan Zhan,Lan Yao,Ya Xiong,Shuanghong Tian
Herein we reported the first example of preparing α-MnO 2 by selective acid etching from Mn-containing spinel. The defects, facet, and surface area of α-MnO 2 were cooperatively engineered by an all-in-one acid etching method to enhance the defect accessibility to the reactants. The obtained highly porous α-MnO 2 nanorods have rich defects of Mn 3+ (24.9%) and oxygen vacancies (31.4%), mainly active crystal facets of (110), and an ultrahigh surface area of 271.1 m 2 /g. With α-MnO 2 nanorods as the catalysts, more than 90.9% of 4-chlorophenol can be degraded within 12 min by catalytic ozonation in a wide work pH of 4.5–10.5. The experiments and DFT theory calculations reveal that α-MnO 2 with (110) facet promotes the adsorption and activation of ozone directly over the defects or indirectly over H 2 O adsorbed on the defects. Thus, more reactive oxygen species (e.g., •OH, •O 2 - , 1 O 2 , surface *O) are generated and get involved in pollutant degradation. This work provides a facile method to maximize the defect accessibility, and a deeper mechanistic study to understand the roles of the defects.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Siyi Wang,Junping Ma,Chen Wang,Wenke Xi,Yuxuan Bai,Wen Lu,Jianjun Wang
To effectively treat the contamination caused by radionuclide uranium (VI) in wastewater discharged from the nuclear industry, it is necessary to investigate novel nanomaterials with powerful adsorption capacities. In this study, a novel composite nanomaterial α-MnO 2 @CTS was successfully synthesized by coating nano manganese dioxide (α-MnO 2 ) with chitosan (CTS) using a straightforward method. The effects of the pH, ionic strength, presence of coexisting ions, time, temperature, cycle number and stability on U(VI) removal were investigated. The results showed that U(VI) elimination by α-MnO 2 @CTS was strongly dependent on the pH but weakly influenced by the NaNO 3 concentration, which indicated complexation on the inner-sphere surface. At pH = 6.0 ± 0.1 and T = 298 K, α-MnO 2 @CTS had an adsorption capacity of up to 326.54 mg/g toward U(VI), which was consistent with the results of a Langmuir adsorption isotherm model. In various studies, the high removal rate of U(VI) by α-MnO 2 @CTS has been attributed to electrostatic attraction, and hydroxyl and amide groups introduced by CTS are also considered to play a key role in the adsorption process. In conclusion, α-MnO 2 @CTS can efficiently and rapidly adsorb U(VI) under acidic conditions, indicating broad application prospects for radioactive wastewater treatment.
研究领域:
环境科学
·
纳米技术
·
放射性废物管理
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Juanjuan Feng,Yu Tian,Kunlin Li,Fei Wang,Kai Li,Ping Ning
Toxic H 2 S limits the high-value utilization of high-concentration CO in yellow phosphorus tail gas. High-performance adsorbents play a significant role in the purification of yellow phosphorus tail gas and the recovery of CO. In this study, manganese-based adsorbents doped with other metals (Cu, Co, Ni, Ce, and Fe) were synthesized and tested for H 2 S removal. The results demonstrate that doping α-MnO 2 with metals significantly enhances its desulfurization performance. Notably, the 20 % Ni/Mn adsorbent achieves the best performance, exhibiting an adsorption duration of approximately 50 h under test conditions and H 2 S capacity up to 854.35 mg/g. Mechanism studies show that the performance improvement is mainly attributed to the doping of Ni, which disrupts the growth of the α-MnO 2 rod-like structure, promoting the formation of fine particles and exposing more crystal interfaces. This is conducive to the migration and release of active lattice oxygen species on the adsorbent, thereby enhancing the adsorption-oxidation performance of the adsorbent for H 2 S. Moreover, Ni significantly promotes the formation of high-valent Mn, enhancing the adsorbent’s oxidation capability and facilitating the decomposition of H 2 S. This study proposes an innovative synthetic strategy for constructing adsorbents with high H 2 S adsorption performance under anaerobic and dry conditions.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Qilei Yang,Qi Li,Lei Li,Yue Peng,Dong Wang,Yongliang Ma,Junhua Li
The elimination of benzene, a typical volatile organic pollutant, is one of the most challenging topics for environmental scientists. Catalytic oxidation technology is considered the most efficient approach for its elimination. Herein, we report the successful preparation of a novel α–MnO 2 –like rod catalyst via an acid etching route and propose YMn 2 O 5 mullite as a novel precursor. The optimized α–MnO 2 –like rod catalyst showed significantly improved benzene oxidation activity compared to the raw YMn 2 O 5 and commercial MnO 2 catalysts, resulting in 100 % benzene conversion at 200 °C at a GHSV of 60,000 mL g –1 h –1 . Notably, the α–MnO 2 –like rod catalyst performance at lower temperatures (100–175 ℃) exceeded that of a commercial Pt/Al 2 O 3 catalyst. The excellent catalytic performance of the α–MnO 2 –like rod catalyst is associated with its low–temperature reducibility and abundant surface–active oxygen species. During the acid etching process, more Mn 3+ is oxidized to Mn 4+ , and more surface oxygen vacancies are generated on the α–MnO 2 –like rod catalyst, which provides more adsorption sites for oxygen molecules to promote the benzene oxidation reaction. The α–MnO 2 –like rod catalyst should be a great alternative to commercial noble metal catalysts for the elimination of volatile organic pollutants, especially at lower temperatures.
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
危险品化学品经营许可证（带存储）