SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Yalong Duan,Jiang Yu,Ruxia Zhang,Pengfei Han,Ping Ren,Min Liu,Ngie Hing Wong,Jaka Sunarso
Membrane filtration integrated with micro-nano bubbles (MNBs) is an attractive technology for treating dye wastewater given its efficiency and environmental compatibility. However, the amount of ·OH generated during the disintegration of MNBs is insufficient in practical applications. This work presents the characterisation of a modified Al 2 O 3 ceramic membrane (CM) with the MnO 2 nanosheet (MnO 2 /Al 2 O 3 CM), which provides dual functions of membrane filtration and MNB catalysis. Here, a novel MNB catalytic membrane reactor (MNB-CMR) was constructed by applying the modified MnO 2 /Al 2 O 3 CM for treating the simulated dye wastewater, i.e., methylene blue (MB). The MB degradation showed that the MNB-CMR improved 17% decolorization rate and 20% total organic carbon removal rate compared to the integrated MNB process with the non-modified CM. The MNB-CMR exhibited excellent catalytic performance and fouling resistance. Besides, the effects of MNB-CMR operational parameters such as the initial methylene blue (MB) concentration, reaction temperature, solution flux, and solution pH on the MB degradation performance were investigated. Based on the scavenging experiments of reactive oxygen species (ROS), the reaction of singlet oxygen ( 1 O 2 ) or hydroxyl radicals (·OH) was elucidated as the primary ROS responsible for the oxidation of MB in the MNB-CMR. In addition, the XPS results showed that the redox couple of Mn(IV)/Mn(III) on the surface of the MnO 2 /Al 2 O 3 CM was responsible for MNB catalysis. Finally, we proposed a possible degradation pathway of MB. This work shows an attractive alternative wastewater treatment process to relieve membrane fouling and enhance MNB catalysis concurrently.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Dongwei Xu,Zhihao Shen,Mingju Zhang,Xinyuan Li,Lu Deng,Yeqi Ren,Biao Zhao,Xiaoqin Guo,Ping Chen
The rational structural design and compositional merits as well as the synergistic coupling effect can break the properties of single material and broaden the microwave absorption band. Herein, the unique lightweight Fe-doped MnO 2 @C hollow nanocubes are rationally designed and successfully synthesized via a scalable wet chemical process and polydopamine coating followed by high-temperature calcination . By virtue of the unique structure and compositional merits, the as-obtained Fe-doped MnO 2 @C hollow nanocubes (Fe–MnO 2 @C-HNBs) displayed notable microwave absorption performance (MAP), simultaneously achieving ultra-broad absorption bandwidth and strong absorption characteristics at a low thickness of 2.3 mm (the reflection loss of −41.02 dB and the effective absorption bandwidth of 5.86 GHz). Surprisingly, the effective absorption bandwidth (RL < −10 dB) could reach up to 8.08 GHz and the minimum reflection loss (RLmin) was −38.20 dB at the thickness of 2.7 mm. The results further confirmed that the excellent microwave attenuation ability of the as-prepared Fe–MnO 2 @C-HNBs composites benefitted from the special “air@core-shell” structure and multiple heterointerfaces as well as multi-component recombination. These results demonstrated that the as-obtained Fe–MnO 2 @C-HNBs composites could be attractive candidates for broadband microwave absorption materials .
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Wenhui Tian,Penggang Ren,Xin Hou,Runzhuo Xue,Zhengyan Chen,Zhengzheng Guo,Yanlin Jin,Fang Ren
Preparing electrode material integrated with high gravimetric/volumetric capacitance and fast electron/ion transfer is crucial for the practical application. Owing to the structural contradiction, it is a big challenge to construct electrode material with high packing density, sufficient ion transport channels, and fast electronic transfer pathways. Herein, MnO 2 porous carbon composite with abundant porous structure and 3D carbon skeleton was facilely fabricated from Linum usitatissimum . L stems via NaOH activation and MnO 2 introduction. The in-situ introduced MnO 2 not only increases the packing density and the electrical conductivity of the porous carbon but also provides more active sites for oxidation reactions . These unique characteristics endow the resultant MnO 2 porous carbon composite with remarkable gravimetric capacitance of 549 F g −1 , volumetric capacitance of 378 F cm −3 , and capacitance retention of 54.9 %. Giving the simple process and low cost, this work might offer a new approach for structural design and the practical application of high-performance electrode materials.
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Mingjie Guo,Xiang Jiang,Heqing Fu
First, [(1-x)MnO2-xMWCNTs] (MMCs) nanocomposites and modified [(1-x)MnO2-xMWCNTs] (mMMCs) nanocomposites were synthesized. Then, novel modified [(1-x)MnO2-xMWCNTs]/waterborne polyurethane (mMMCs/WPU) composites with good microwave absorption properties were prepared by in situ polymerization. The chemical functionalized MMCs and mMMCs nanocomposites were characterized by FTIR and XRD. The structure and properties of the mMMCs/WPU composites were investigated by SEM, TGA, tensile testing, and vector network analyses. The experimental results showed that when the mMMCs nanocomposites were introduced into WPU the thermal stability and tensile strength of mMMCs/WPU composites were improved. When the content of MWCNTs was 20 wt % (where x = 0.2), m[(1-x)MnO2-xMWCNTs]/WPU composites exhibited good microwave absorption properties. The minimum RL value can reach −28.7 dB at 6.4 GHz with a thickness of 2.5 mm. The mMMCs/WPU composites have good thermal stability and tensile strength, which could be used as promising materials for microwave absorption.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Energy & Environmental Materials
·
2022
·Vol. 6
·期 3
·e12376
·
IF 13.443
Jiaxin Ren,Yang Ding,Jiang Gong,Jinping Qu,Ran Niu
Harvesting solar energy in an effective manner for steam and electricity generation is a promising technique to simultaneously cope with the energy and water crises. However, the construction of efficient and easy scale-up photothermal materials for steam and electricity cogeneration remains challenging. Herein, we report a facile and cost-effective strategy to prepare MnO 2 -decorated cotton cloth (MC x ). The wide adsorption spectrum and excellent photothermal conversion ability of the in situ-formed MnO 2 nanoparticles make the MC x to be advanced photothermal materials. Consequently, the hybrid device integrated with MC x as the photothermal layer and the thermoelectric (TE) module for electricity power conversion exhibits an extremely high evaporation rate of 2.24 kg m −2 h −1 under 1 kW m −2 irradiation, which is ranked among the most powerful solar evaporators. More importantly, during solar evaporation, the hybrid device produces an open-circuit voltage of 0.3 V and a power output of 1.6 W m −2 under 3 Sun irradiation, and outperforms most of the previously reported solar-driven electricity generation devices. Therefore, the integrated device with synergistic solar-thermal utilization opens up a green way toward simultaneous solar vapor and electric power generation in remote and resource-constrained areas.
研究领域:
材料科学
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能源技术
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Zhao Wang,Yurou Wang,Yuxuan Lin,Gang Bian,Hai-Yang Liu,Xiang Li,Jun Yin,Jian Zhu
Aqueous zinc-ion batteries (ZIBs) have gained wide attention for their low cost, high safety, and environmental friendliness in recent years. β-MnO2, a potential cathode material for ZIBs, has been restricted by its small channels for efficient charge storage. Herein, β-MnO2 nanorods with oxygen vacancies are fabricated by a K+-doping strategy to improve the performance of ZIBs. The assembled batteries exhibit a capacity of 468 mAh g–1, a power density of 2605 W kg–1, and an energy density of 179 Wh kg–1, which outperforms most reported ZIBs. Such a performance is owing to the synergistic combination of the oxygen vacancies in β-MnO2 and concurrent deposition of ε-MnO2 from Mn2+ in the electrolyte. Furthermore, superior cycling stability with negligible capacity decay in these batteries is demonstrated over 1000 cycles at a high current of 2 A g–1. This study reveals the importance of oxygen vacancies and Mn2+ deposition effect in understanding the mechanism of charge storage in MnO2-based ZIBs.
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
MATERIALS RESEARCH BULLETIN
·
2022
·
IF 5.6
Yun-Long Zhang,Xue-Wei Wang,Ke Ma,Xiao-Ran Wen,Zhong-Qing He,Zhi-Hao Yuan
In this work, sea urchin-like SmMn 2 O 5 /MnO 2 is synthesized by the hydrothermal method . Compared with SmMn 2 O 5 , SmMn 2 O 5 /MnO 2 has a half wave potential of 0.82 V (vs RHE), which shows excellent electrocatalytic activity of oxygen reduction reaction (ORR) in the alkaline media. More importantly, the composite of SmMn 2 O 5 /MnO 2 shows higher number of electron transfers , better stability of ORR, and stronger methanol-tolerant ability comparison with the commercial catalyst of Pt/C. The remarkable ORR activity is due to the formation of abundant oxygen vacancies and Mn 3+ , which are beneficial to the adsorption of oxygen species and the activation of O-O bond. The sea urchin-like morphology increases the specific surface area, and the tip-like synapses play an essential role in charge accumulation and rapid transfer. Moreover, the rechargeable zinc-air battery made of SmMn 2 O 5 /MnO 2 not only has a high peak power density, but also has excellent cycle stability of 450 h in long-term charge discharge measurement.
研究领域:
材料科学
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电化学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2022
·
IF 4.831
Haiping Zhao,Ziyi Zhang,Yong Han,Weixia Yang,Wenzhi Tang,Tianli Yue,Zhonghong Li
A nanocomposite (UiO-66/Ce-MnO 2 ) was fabricated by combining UiO-66 with cerium-doped manganese dioxide (Ce-MnO 2 ) for colorimetric detecting vitamin C (Vc). Compared with traditional artificial enzymes, the as-synthesized UiO-66/Ce-MnO 2 were simple to prepare and did not require the participation of other active substances. The doping of cerium increased the oxygen vacancies and the UiO-66 as a carrier improved the dispersibility. The formation of superoxide anion (O 2 − ) and the inside Ce 4+ /Ce 3+ and Mn 4+ /Mn 3+ redox couples of UiO-66/Ce-MnO 2 endowed UiO-66/Ce-MnO 2 with a high catalytic capability, which could catalytically oxidize 3, 3′, 5, 5′-tetramethylbenzidine (TMB) into oxidation state TMB (oxTMB) without H 2 O 2 , accompanying with color change and a prominent peak at 652 nm in UV–vis spectra. Based on the inhibitory effects of Vc on catalytic oxidation of TMB, detection of Vc can be achieved, exhibiting a linear relationship in the concentration of 1.13–17.01 μmol L −1 with a low detection limit of 65.82 nmol L −1 . This system can also be detected by smartphone, the linear detection range is 12.47–22.67 μmol L −1 . Vc contents in fruits and vegetables detected by the sensor were in good agreement with the 2, 4-Dinitrophenylhydrazine colorimetry method ( P > 0.05), indicating a reliable sensor for Vc detection.
研究领域:
生物化学
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食品科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 6
·15377-15391
·
IF 5.19
Wang Junwei,Zhang Di,Nie Fan,Zhang Ruixue,Fang Xiaojie,Wang Yaxin
MnO 2 , as a representative manganese-based catalyst with many kinds of crystal forms, has been widely used to activate PMS. However, the role of morphological scale and crystal structures on the catalytic capability of MnO 2 still lacks further study. In this study, four different crystal forms of MnO 2 (α-MnO 2 , β-MnO 2 , γ-MnO 2 , and δ-MnO 2 ) are succeeded in being fabricated via hydrothermal processes and evaluated by activating PMS for the removal of Reactive Yellow X-RG, typical azo dye. Experiment results indicate that α-MnO 2 with a one-dimensional structure exhibits the best catalytic performance among the four as-prepared MnO 2 , which can be attributed to its broadest crystal interplanar distance (0.692), the highest portion of Mn (III)/Mn (IV) (4.194), and lowest value of average oxidation state AOS (2.696). Correlation analysis confirms that interplanar distance is the most relative factor with the catalytic activity of MnO 2 among the three studied factors ( R 2 = 0.99715). Meanwhile, the morphological scale structure of α-MnO 2 can also account for its highest catalytic ability among the four as-prepared MnO 2 , including its large specific area and advantageous one-dimensional nanostructure. Furthermore, according to the response surface methodology, when the dosage of PMS is 2.369 g/L, the dosage of α-MnO 2 is 0.991 g/L, and the initial dye concentration is 1025 mg/L, the maximum removal rate of Reactive Yellow X-RG is up to 97.38%. Graphical abstract
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
·
2023
·
IF 15.1
Minjia Meng,Yi Li,Hui Peng,Binrong Li,Chuanxun Zhang,Jiajia Ren,Qingluola Ren,Yan Liu,Jianming Pan
The selective separation and purification of ART and ARE using molecularly imprinted membrane (MIM) has attracted considerable attention, but most of conventional blending MIM face low adsorption capacity and poor selectivity due to the blockage of imprinting sites. Herein, an alternative ART imprinted MnO 2 nanowires “coating” membrane (MINM) with hydrophilicity was fabricated by vacuum filtration of imprinted MnO 2 nanowires and graphene oxide nanosheets on PVDF membrane surface for selective ART separation. For the MINM, the imprinted MnO 2 nanowires coating offers more available exposed imprinting sites on the MINM surface compared to that of the blending MIM, while the introduction of graphene oxide improves the hydrophilicity of MINM, significantly reducing the non-specific absorption. Consequently, the MINM exhibits ultrahigh ART adsorption capacity and selectivity, with the ART adsorption amount of 335 mg g −1 at 5 min using dynamic cross-flow separation system, about 12.18 times higher than that of ARE (27.5 mg g −1 ), and the separation factor ( a ) value of 12.39. Moreover, the ATR FT-IR dynamic spectrum discloses the in-situ formation of H-bond between ART and MINM, playing a key role in the selective adsorption process. This work provides an alternative strategy to prepare “coating” MIM for high-efficient and selective separation of complex analogue systems.
研究领域:
材料科学
·
药物化学
·
分离技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Junjie Qian,Tao Wang,Qingliang Shan,Shaohua Wang,Xiaozhen Zhang,Xuebing Hu,Qibing Chang,Yongqing Wang
Silicon carbide (SiC) is expected to be the new-generation electromagnetic wave (EMW) absorber. In this context, the SiC/C composites were first prepared through a hydrothermal method using glucose as the carbon source. Then SiC/MnO 2 composites were fabricated by a second hydrothermal reaction using potassium permanganate (KMnO 4 ) as raw material. With glucose content increased to 10 wt%, the composition exhibited outstanding EMW absorption performance with the minimum reflection loss value of − 55.7 dB at the frequency of 2.1 GHz, and effective absorption bandwidth can cover the entire S-band by adjusting sample thickness. Therefore, the SiC/MnO 2 composites present a promising EMW-absorbing material for low-frequency applications.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Fuzheng Fu,Furui Hu,Zi Yu,Yongxin Liang,Tao Gan,Huayu Hu,Zuqiang Huang,Yanjuan Zhang
The existing photocatalytic systems are difficult to achieve high selectivity and conversion for the oxidation of 5-hydroxymethylfurfural (HMF) under mild conditions. MnO 2 exhibits notable tunability in valence state, but its photocatalytic oxidation efficiency is limited by the poor absorption in near-infrared region, insufficient oxygen adsorption, and slow charge transfer. To overcome these limitations, an innovative MnO 2 @Bi 2 MoO 6 /kaolinite (MnO 2 @BMO/KL) composite photocatalyst was synthesized by the hydrothermal and co-precipitation techniques, and the as-prepared photocatalyst was used for selective photocatalytic oxidation of HMF to produce 2,5-diformylfuran (DFF). The combination of MnO 2 , three-dimensional layered Bi 2 MoO 6 (BMO), and kaolinite enhanced electron transport and oxygen adsorption. The incorporation of kaolinite as a support material led to the structural transformation of BMO, while the in-situ grown amorphous MnO 2 trapped and accelerated electron transfer to adsorbed O 2 , thus efficiently segregating the photo-generated charges to enhance the utilization rate. MnO 2 @BMO/KL achieved almost complete conversion of HMF (>99.0 %) and a DFF yield of 83.0 % after 6 h of visible light irradiation. Additionally, MnO 2 @BMO/KL exhibited excellent structural stability over 6 cycles. The synergistic action of singlet oxygen ( 1 O 2 ) and superoxide ( • O 2 − ) was crucial in promoting the selective oxidation of HMF, while minimal generation of hydroxyl radical (•OH) reduced the risk of overoxidation. This study provides new insights into the development of economical and stable non-precious metal photocatalysts for highly selective conversion of biomass-derived chemicals.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 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）