SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Yuanxuan Chen,Jianyou Long,Sihao Chen,Yuan Xie,Zhengfan Xu,Zengping Ning,Gaosheng Zhang,Tangfu Xiao,Mingxia Yu,Yanyang Ke,Lihu Peng,Huosheng Li
Water pollution caused by the release of manganese (Mn 2+ ) and ammonia nitrogen (NH 4 + -N) from electrolytic manganese residue (EMR) generated from industrial activities poses a serious threat to ecosystems and human health. In this study, an integrated process consisting sequentially of hydroxide sedimentation, struvite precipitation, breakpoint chlorination, and ferric chloride coagulation was optimized to remove Mn 2+ and NH 4 + -N from EMR leachate, and to address the issue of residual orthophosphate caused by struvite precipitation. The precipitates were characterized using X-ray diffraction, scanning electron microscopy, and thermogravimetric analyses. Results show that Mn 2+ ions and the resulting chemical oxygen demand (COD) were mainly removed using hydroxide precipitation at a sedimentation pH of 10.2, with poor-crystalline manganese hydroxide as the main precipitate. NH 4 + -N was primarily removed and recovered using struvite precipitation with well crystalline struvite as the main product, and then further eliminated using breakpoint chlorination. The residual orthophosphate introduced by struvite precipitation is successfully removed with ferric coagulation, and the effluent pH (7.5) is also lowered to discharge limits by means of hydrolysis of ferric coagulant. The concentration of COD, Mn 2+ , NH 4 + -N, and orthophosphate concentrations in the final effluent were 30.52 ± 9.38, 0.026 ± 0.013, 0.87 ± 0.01, and 0.06 ± 0.002 mg/L, respectively, meeting all local discharge standards. This combined process has robust pollutant removal efficiency, high resource recovery potential and few environmental constraints; thus, it is recommended as a potential solution for the treatment of Mn 2+ - and NH 4 + -N-rich acid mine drainage .
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
IONICS
·
2018
·Vol. 25
·期 6
·2585-2594
·
IF 2.347
Meng Fanbo,Guo Huajun,Wang Zhixing,Wang Jiexi,Yan Guochun,Wu Xianwen,Li Xinhai,Zhou Lijiao
A series of layered Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 cathode materials, of which manganese source was electrolytic manganese dioxide, with different contents of SO 4 2− were successfully synthesized via ball-milling process and solid-state sintering method. The obtained materials were characterized by XRD, XPS, SEM-EDS, C-S, ICP, and HR-TEM. All the obtained materials presented well-ordered layered structure. When the content of SO 4 2− was below 1.30 wt%, the electrochemical properties and structural stabilities at low rate for the layered materials with SO 4 2− were not changed dramatically, while when the content of SO 4 2− increased to 5.85 wt%, the initial discharge capacities decreased dramatically from 248.24 to 209.23 mAh g −1 at 10 mA g −1 . And the pristine sample shows excellent cyclic property and rate capability. It delivered the discharge capacity of 175.25 mAh g −1 after 100 cycles with the highest capacity retention of 90.67% at 200 mA g −1 . Particularly, the treated Li-rich Mn-based materials with the highest amount of SO 4 2− exhibited the best cyclic stability and it delivers the highest capacity retention of 95.17% after 100 cycles at 200 mA g −1 . However, its discharge capacities were much lower than the pristine material. As a result, the addition of SO 4 2− could promote side reactions between electrode and electrolyte and deep-degree corrosion of electrode materials to affect the electrochemical properties and structural stabilities of the Li-rich Mn-based materials.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Xin Liu,Zhang Chen,Chengyu Zhang,Changsheng Ding,Haitao Feng,Yuanyuan Cui,Yanfeng Gao
Manganese (Mn)-based redox flow batteries (RFBs) have emerged as promising candidates for large-scale energy storage owing to their high redox potential (Mn 2+ /Mn 3+ : 1.58 V vs SHE), cost-effectiveness, and sustainability. Nevertheless, Mn-based RFBs face a critical challenge: the undesired formation of crystalline MnO 2 through Mn 3+ disproportionation and irreversibility of MnO 2 deposits on electrode surfaces severely diminish accessible reaction sites and restrict achievable areal capacity. Herein, it is demonstrated that ligand chelation-mediated structural transformation of MnO 2 by sodium diphosphate (Na 4 P 2 O 7 , PPi) modulates MnO 2 deposition behavior. The PPi coordinate with Mn 2+ to form a stable [Mn(HPO 4 ) 2 (H 2 O) 2 ] 2− chelate, which facilitates the incorporation of defective O and P into the evolving MnO 2 structure, effectively disrupting its crystallographic ordering and converting MnO 2 from crystalline to amorphous configuration. The amorphous MnO 2 tends to flow into the electrolyte instead of depositing on the electrode due to the electrostatic interplay, thereby resulting in a breakthrough areal capacity of 91.5 mAh cm −2 (300 cycles @ 99.7% CE) and 141.8 mAh cm −2 (150 cycles @ 98.2% CE, the highest reported values), representing a 10-fold enhancement compared to additive-free counterparts. The ligand chelation modification of MnO 2 provides a new pathway for developing high-areal-capacity Mn-based RFBs.
研究领域:
能源存储
·
电化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Mingjun Nan,Min Wu,Zichao Zhao,Lin Qiao,Huamin Zhang,Xiangkun Ma
Manganese-based flow battery has attracted wide attention due to its nontoxicity, low cost, and high theoretical capacity. However, the increasing polarization at the end of the charging process greatly limits the battery capacity. Here we found that the introduction of specific transition metal ions could induce the formation of uniform MnO 2 layer on the cathode of titanium-manganese flow batteries. Excitingly, the uniform MnO 2 layer can catalyze the electrochemical reaction of Mn 2+ to Mn 3+ , and then obviously enhance the charge capacity. Herein, the MnO 2 layer formation mechanism and catalysis effect of the MnO 2 layer have been analyzed in detail. More interestingly, the MnO 2 layer would be consumed at the end of the discharge process and regenerated again after the next charge process. Different from the conventional catalysts, the MnO 2 layer could self-heal in every cycle, which could mitigate the fall-off and deactivation risk of the catalyst and prolong the cycle life of the battery. As a result, the TMFB achieves a volume capacity of 45 Ah L −1 and runs over 400 charge–discharge cycles (42 days). Besides, the design route of a self-healing catalyst was summarized in the work, which is expected to be applied widely in the electrochemical systems.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Yi Yang,Jia Fang,Zhongwei Meng,Ping Pu,Qian Zhang,Chengcheng Yi,Suozhu Pan,Yalong Li
To solve the soot elimination and optimize catalyst diesel particulate filter (CDPF) regeneration strategies, a series of Mn-Ce catalysts with different Mn/(Mn+Ce) molar ratios are successfully synthetized by hydrothermal method and the complete catalytic oxidation of diesel engine soot are investigated. Compare to CeO 2 and MnO 2 , the catalytic promotion on soot combustion of Mn-Ce catalysts is more excellent by thermogravimetric experiments due to their better ability to activate oxygen species, which is consistent with results in characterization analysis. Among as-prepared catalysts, MC-0.40 has the best catalytic activity with the lowest starting temperature ( T s ), peak temperature ( T p ) and largest comprehensive combustion index ( S ) both in O 2 /N 2 and NO/O 2 /N 2 atmosphere. Influence factors on catalytic performance are studied. Weight ratios of soot/MC-0.40 catalyst are suitable at the range of 1:9–1:13, which makes soot combustion more easily. Ashes in the reaction process show adverse effects due to their ability to increase ignition point by inhibit heat and oxygen transfer. Mn-Ce catalysts are more sensitive and show better catalytic activity in NO atmosphere because of generations of abundant adsorbed species and NO adsorption/desorption. The three consecutive cycles of MC-0.40 catalyst are performed to study the catalytic stability, and thermogravimetric curves show that the potential reusability of MC-0.40 catalyst can be relatively accepted in soot combustion.
研究领域:
环境科学
·
催化材料科学
✓ 已验证
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2016
·Vol. 23
·期 11
·1346-1351
·
IF 0.882
Jiang Peng,Yang Wen-hui,Zhou Yun-cheng,Kuang Jian-lei,Li Yong,Xiao Ting
Brownmillerite-type oxides Ba 2 In 2− x − y
Mn
x
Al
y
O 5+ x
(0 ≤ x ≤ 0.6, 0 ≤ y ≤ 0.5) were prepared at 1300°C through solid-state reaction. X-ray diffraction (XRD) analysis showed that the structure symmetry evolved from orthorhombic to cubic with increasing Mn and Al contents. When y was greater than 0.3, peaks associated with small amounts of BaAl 2 O 4 and Ba 2 InAlO 5 impurities were observed in the XRD patterns. When substituted with a small amount of Mn ( x ≤ 0.3), the Ba 2 In 2− x − y
Mn
x
Al
y
O 5+ x
samples exhibited an intense turquoise color. The color changed to green and dark-green with increasing Mn concentration. UV–vis absorbance spectra revealed that the color changed only slightly upon Al doping. The valence state of Mn ions in Ba 2 In 2− x − y
Mn
x
Al
y
O 5+ x
was confirmed to be +5 on the basis of X-ray photoelectron spectroscopic analysis. According to this analysis, the intense turquoise color of the Ba 2 In 2− x − y
Mn
x
Al
y
O 5+ x
samples is rooted in the existence of Mn 5+ ; thus, the introduction of Al does not affect the optical properties of the compounds.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2022
·
IF 6.959
Hui Peng,Faqiang Wang,Danyang Wang,Shuzhen Cui,Wenbo Hou,Guofu Ma
Aqueous Zn–MnO2 batteries have received much attention due to their low cost, safety, reliability, and large storage capacity. However, the sluggish ion/electron transport kinetics of bulk MnO2 inevitably decreases the rate capability and cycle stability of Zn–MnO2 batteries. Herein, hierarchical MnO2 nanosheet arrays self-anchored and grown in polyaniline-derived carbon nanotubes (PCNT@MnO2, denoted as PCMO) with enhanced stability are prepared by employing PCNT as both a substrate and a sacrificial reductant. The hollow PCNT conductive skeleton feature and robust integrated MnO2 nanosheet arrays in PCMO are not only favorable for enhancing electronic conductivity and accelerating electronic migration but also provide effective nucleation sites for the growth of MnO2 nanosheets and unimpeded ion channels, resulting in high specific capacity, rapid ion-diffusion kinetics, and long-term cycle stability. Specifically, the optimized PCMO material (PCMO-2) can deliver 264 mAh g–1 at 0.2 A g–1 after 120 cycles without obvious capacity decay, superior to the bare MnO2 material. Moreover, the as-fabricated PCMO//Zn battery can exhibit a high energy density of 320.2 Wh kg–1 at a power density of 120 W kg–1. The rational design of low-cost and integrated core–shell architecture with robust contact between MnO2 nanosheet arrays and a hollow conductive skeleton is expected to achieve cost-effective and high-performance Zn–MnO2 batteries.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2022
·
IF 7.926
Mengyue Zhang,Jun Dong,Minglu Sun,Chen Sun,Yujiao Han,Yanyang Mo,Weihong Zhang
The remediation of trichloroethylene contaminated groundwater by permanganate-based in situ chemical oxidation is limited by MnO 2 formation. The application of phase transfer catalyst (PTC) is a promising alternative to enhance remediation efficiency, and the alleviation of MnO 2 generation is one of crucial capacities of PTC to promote oxidation. This work has emphatically elucidated the mechanism of MnO 2 alleviation by PTC, as well as the effectiveness which was researched by conducting batch and sand column experiments. The results indicated that the contents of MnO 2 suspended in aqueous phase and total manganese in the media were respectively decreased by 29.5% and 26.1% attributed to PTC addition. Although PTC could not be used as a chelator for Mn(Ⅲ) stabilization, the generation of dissolved Mn(Ⅱ) and Mn(Ⅲ) was promoted by PTC for less MnO 2 generation. Further studies illustrated that redox reactions would occur between dissolved Mn(Ⅱ)/Mn(Ⅲ) and TCE, which benefited TCE degradation. Moreover, Smaller particle size and improved colloidal stabilization of formed MnO 2 were achieved by PTC to minimize MnO 2 precipitation. Overall, effective alleviation of the MnO 2 generation and precipitation by PTC is collectively contributed from the promotion of dissolved Mn(Ⅱ) and Mn(Ⅲ) and the stabilization of MnO 2 formed in situ.
研究领域:
环境科学
·
化学工程
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
Small Methods
·
2022
·Vol. 7
·期 1
·2201266
·
IF 15.367
Mingjun Nan,Min Wu,Yuqin Liu,Lin Qiao,Huamin Zhang,Xiangkun Ma
Aqueous manganese-based flow batteries (AMFBs) have attracted great attention due to the advantages of low cost and environmental friendliness. Extending the cycle life of AMFBs has long been a challenging theme. The titanium-manganese single-flow batteries (TMSFB) are promising due to their special structure and electrolyte composition. However, TMSFB with high areal capacity faces capacity decay for unknown reasons. In this work, the capacity decay mechanism (accumulation and growth of MnO 2 ) is clarified by a homemade in situ microscope system. Given that, a redox mediator of Fe 2+ /Fe 3+ is specially designed to boost the areal capacity of TMSFB without side reaction. The directional promoting principle of the Fe 2+ /Fe 3+ is elaborated in detail. Fe 2+ chemically reacts with the residual MnO 2 to form Fe 3+ , which is reduced to Fe 2+ by the electrochemical reaction. And then Fe 2+ continues reacting with MnO 2 until MnO 2 is consumed completely. As a result, the TMSFB with the areal capacity of ≈55 mA h cm −2 can stably operate at a current density of 40 mA cm −2 , which is the highest areal capacity reported in aqueous manganese-based batteries. This work provides a new strategy for boosting the capacity of manganese-based batteries, shedding light on the improvement of other deposition-type batteries.
研究领域:
电化学
·
能源材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Rui Wang,Huizhi Hu,Danting Shi,Jinsong Liang,Senlin Shao
Biogenic manganese oxides (BioMnO x ) can effectively remove Mn(II) from drinking water. In the gravity-driven membrane (GDM) system for Mn(II)-containing water treatment, both BioMnO x and Mn(II)-oxidizing bacteria (MnOB) present in the cake layer, and their role in Mn(II) oxidation is still controversial. To address this issue, in this study, we naturally formed a cake layer containing BioMnO x and MnOB using the GDM process and identified the different roles of BioMnO x and MnOB in the removal of Mn(II). The experimental results showed that the BioMnO x accounted for a major proportion of the cake layer of GDM, and it played a principal role in the removal of Mn(II) through the combination of adsorption and catalytic oxidation. However, this removal efficiency would be continuously reduced in the absence of MnOB, while stabilized in the presence of MnOB. XPS analysis revealed that the proportion of Mn(III) and Mn(IV) in BioMnO x with MnOB reached 64.1% and 35.8%, respectively, while BioMnO x without MnOB did not contain Mn(IV). These findings suggest that BioMnO x may be the primary catalyst for Mn(II) oxidation, but its long-term activity is dependent on MnOB, which can maintain the catalytic activity by 1) producing new BioMnO x and 2) sustaining the high valence state of MnO x .
研究领域:
环境科学
·
水处理
·
微生物学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2023
·Vol. 29
·期 7
·2853-2864
·
IF 2.8
Wang Wenping,Zhao Zhiyi,Deng Jiayao,Lang Wei,Zhen Lipeng,Lu Huimin
The oxygen reduction reaction of the cathode in an Al-air battery plays a key role in the performance of the entire battery. Generally, Pt and its alloys are recognized as catalysts with high oxygen reduction catalytic performance, but their application is limited by the rare earth content and high cost. In this paper, α-MnO 2 nanotubes are prepared using a hydrothermal method and used as a template. Nano-Ni–Mn bimetallic oxides with different compositions are prepared with different NiO and α-MnO 2 ratios by calcination. The effects of morphology, phase, and Mn 3+ /Mn 4+ and Ni 3+ /Ni 2+ ratios on electrochemical performance and battery discharge performance are analyzed. The results show that the contents of α-MnO 2 and Ni 6 MnO 8 in NM-12 catalyst are low, and the molar ratio of Mn 3+ /Mn 4+ and Ni 3+ /Ni 2+ is high. Also, the specific surface area of NM-12 is relatively high. Finally, the catalyst prepared with a NiO to α-MnO 2 ratio of 1:2 shows better electrochemical catalytic performance and battery discharge performance that is comparable to that obtained for a commercial 20 wt% Pt/C catalyst.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
Advanced Electronic Materials
·
2024
·Vol. 10
·期 6
·2300809
·
IF 5.3
Abdul Basit,Jiwu Xin,Yubo Luo,Ji-Yan Y. Dai,Junyou Yang
Lead-free polycrystalline manganese telluride holds great potential in the development of waste heat recovery due to its fascinating physical properties. However, the poor thermoelectric (TE) performance in the p-type MnTe alloys always results from their inferior carrier concentration, leading to low power factor and high thermal conductivity which restrict the overall thermoelectric performance. In this work, the problem is solved by decoupling its electrical and thermal transports through the hole donor Ge-deficiency in MnTe + x mol.% GeTe (0 ≤ x ≤ 4) compounds. Intrinsically, extra GeTe in MnTe + x mol.% GeTe compound offers free charge carriers due to a narrow bandgap comparatively, realizing not only a full assessment of stimulated electrical performance but also an enhanced power factor. Moreover, benefiting from the nano-precipitates and tweed microstructures, the lattice thermal conductivity effectively reduces due to the intensive phonon scattering accordingly. Ultimately, a maximum ZT of ≈1.2 at 873 K in the 3 mol.% GeTe doped MnTe sample is realized.
研究领域:
材料科学
·
能源工程
✓ 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）