ENVIRONMENTAL POLLUTION
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2023
·
IF 8.9
Yanyi Liu,Wenhuan Yuan,Wenli Lin,Shan Yu,Lei Zhou,Qingyi Zeng,Jin Wang,Luoheng Tao,Qunwei Dai,Juan Liu
Even though uranium (U) is considered to be an essential strategic resource with vital significance to nuclear power development and climate change mitigation , U exposure to human and ecological environment has received growing concerns due to its both highly chemically toxic and radioactively hazardous property. In this study, a composite (M-BC) based on Ficus macrocarpa (banyan tree) aerial roots biochar (BC) modified by δ-MnO 2 was designed to separate U(VI) from synthetic wastewater. The results showed that the separation capacity of M-BC was 61.53 mg/g under the solid – liquid ratio of 1 g/L, which was significantly higher than that of BC (12.39 mg/g). The separation behavior of U(VI) both by BC and M-BC fitted well with Freundlich isothermal models, indicating multilayer adsorption occurring on heterogeneous surfaces. The reaction process was consistent with the pseudo-second-order kinetic model and the main rate-limiting step was particle diffusion process. It is worthy to note that the removal of U(VI) by M-BC was maintained at 94.56% even after five cycles, indicating excellent reusability and promising application potential. Multiple characterization techniques ( e.g. Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and X-ray Photoelectron Spectroscopy (XPS)) uncovered that U(VI) complexation with oxygen-containing functional groups ( e.g. O–C O and Mn–O) and cation exchange with protonated ≡MnOH were the dominant mechanisms for U(VI) removal. Application in real uranium wastewater treatment showed that 96% removal of U was achieved by M-BC and more than 92% of co-existing (potentially) toxic metals such as Tl, Co, Pb, Cu and Zn were simultaneously removed. The work verified a feasible candidate of banyan tree aerial roots biowaste based δ-MnO 2 -modified porous BC composites for efficient separation of U(VI) from uranium wastewater, which are beneficial to help address the dilemma between sustainability of nuclear power and subsequent hazard elimination.
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高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2023
·
IF 3.8
Muhammad Ishfaq,Safyan Akram Khan,Muhammad Altaf Nazir,Shahid Ali,Muhammad Younas,Muhammad Mansha,Syed Shoaib Ahmad Shah,Muhammad Arshad,Aziz ur Rehman
Zirconium-fumaric based metal organic framework (MOF-801) was synthesised by ultra-sonication method. After synthesis, powder X-ray diffraction (PXRD), UV/Vis spectrophotometer and Fourier transform infrared (FT-IR), were used for its functional group identification. For its structural morphology and elemental composition scanning electron microscopic (SEM) and energy dispersive scanning (EDS) analysis was carried out. After typical characterization, photocatalytic degradation of Rhodamine B (Rh-B) was examined under sunlight by using Zr-fumaric MOF-801 as photocatalyst and revealed the satisfactory results. The MnO 2 @MOF-801 and MnO 2 @MOF-801/Chitosan composite were also synthesized with same ultrasonication method. It was concluded from this study that MnO 2 @MOF-801/Chitosan composite has the good photocatalytic activity about 95 % against the Rhodamine B (Rh-B) in contrast with Zr-fumaric MOF-801 (71 %) and MnO 2 @MOF-801 (86 %) after 45 min of reaction. Valence band (VB) gap and conduction band (CB) corresponding to light-induced transition are used to suggest catalytic mechanism. This newly synthesized non-reported MnO 2 @MOF-801/Chitosan composite as a good photocatalyst initiate the new way for the development of others non-reported MOF coated biopolymer with enhanced photocatalyst activity as an environmental remediation for the control of water pollution.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Guoguang Chen,Shiyu Yan,Chengcheng Ouyang,Lirong Qiu,Jia Liu,Lili Ren
Manganese dioxide (MnO 2 ) nanocrystal, a kind of nanomaterial with excellent enzyme-like catalytic properties, have been widely used in chemical, biological and pharmaceutical fields. It is composed of unique octahedral units that form a variety of tunnels and layered structures, which also lead to the emergence of different crystal forms and properties. In this study, different crystalline types of MnO 2 were synthesized by different methods, and different substrates were used to study MnO 2 catalytic ability of H 2 O 2 . β- MnO 2 nanocrystal had nearly 50% oxygen, among which adsorbed oxygen accounted for nearly 65%, so it exhibited the best catalytic performance and could promote oxidation catalytic reaction well. Furthermore, a functional MnO 2 hydrogel was prepared using β-MnO 2 as antibacterial agent and natural gelatin hydrogel as carrier. The antibacterial performance of the new hydrogel was further studied, and the survival rate of different species of bacteria was<5% after high concentration of MnO 2 functional hydrogel. In the end, MnO 2 functional hydrogel was applied to the wound treatment of mice infected with antibiotic resistant bacteria, and it was found that the wound healing rate of mice was nearly 100% on the 14th day, indicating that it had the potential of a new antibacterial dressing.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
·
IF 9.9
Yi Wang,Jie Wang,Dong Wei,Lan Xu
In this study, a multicore-shell ternary composite electrode material (MnO 2 @Ppy@NPCNFs) with excellent electrochemical performances was prepared by using surface modification, in which core–shell Ppy@N-doped porous carbon nanofibers (Ppy@NPCNFs) with large specific surface area and high conductivity were used as the substrate (a multicore layer), and MnO 2 was loaded on the substrate by hydrothermal synthesis to form a shell layer, further improving the SC of electrode material. The parameters of hydrothermal growth of MnO 2 on Ppy@NPCNFs were explored by means of the control variable method and response surface methodology, and the optimal parameters were predicted and verified. Electrochemical test results showed that the SC of MnO 2 @Ppy@NPCNFs prepared under the optimal reaction parameters was as high as 595.77 F g −1 , and its capacitance retention was 96.2 % after 1000 cycles. Moreover, a symmetric supercapacitor prepared with the optimal multicore-shell electrode showed an energy density of 9.36 Wh kg −1 at a power density of 1000 W kg −1 and a retention rate of 92.46 % after 1000 cycles, indicating the promising application of multicore-shell ternary composite electrode material in high-performance supercapacitors.
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JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Liwei Yang,Fashan Yang,Heng Zhang,Hongyu Zhou,Mengfan Luo,Yunmei Liu,Chuanliang Zhao,Lu Zheng,Bo Lai
At present, the potential mechanism of manganese oxide (MnO 2 ) activation of PI and the key active sites of PI activation are still unclear and controversial. To this end, three different crystal forms of MnO 2 were prepared in this study and used to activate PI to degrade pollutants. The results showed that different crystal types of MnO 2 showed different catalytic abilities, and the order was γ-MnO 2 > α-MnO 2 > β-MnO 2 . Through quenching experiments, EPR tests, Raman experiments and in situ electrochemical experiments, it has been confirmed that electron transfer-mediated non-free radical process is the main mechanism of pollutant degradation , in which the active substance is the highly active metastable intermediate complex (MnO 2 /PI*). Hydroxyl radical (HO • ), superoxide radical (O 2 •− ), singlet oxygen ( 1 O 2 ) and iodine radical (IO 3 • ) did not participate in pollutant degradation. The quantitative structure-activity relationship analysis confirmed that the catalytic performance of MnO 2 was highly positively correlated with the surface Mn(IV) content, which indicated that the surface Mn(IV) site was the main active site. Overall, this study will be of great help to the design and application of manganese dioxide activation for periodate degradation of pollutants.
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高影响因子
Catalysts
·
2023
·Vol. 13
·期 3
·588
·
IF 3.9
Haiou Zhang,Yixin Zhang,Huikang Song,Yan Cui,Yingying Xue,Cai-e Wu,Chao Pan,Jingxin Xu,Jian Qiu,Leilei Xu,Mindong Chen
As a toxic pollutant, carbon monoxide (CO) usually causes harmful effects on human health. Therefore, the thermally catalytic oxidation of CO has received extensive attention in recent years. The CuO-based catalysts have been widely investigated due to their availability. In this study, a series of transition metal oxides (Fe2O3, Co3O4and NiO) promoted CuO-based catalysts supported on the α-MnO2nanowire catalysts were prepared by the deposition precipitation method for catalytic CO oxidation reactions. The effects of the loaded transition metal type, the loading amount, and the calcination temperature on the catalytic performances were systematically investigated. Further catalyst characterization showed that the CuO/α-MnO2catalyst modified with 3 wt% Co3O4and calcined at 400 °C performed the highest CO catalytic activity (T90= 75 °C) among the investigated catalysts. It was supposed that the loading of the Co3O4dopant not only increased the content of oxygen vacancies in the catalyst but also increased the specific surface area and pore volume of the CuO/α-MnO2nanowire catalyst, which would further enhance the catalytic activity. The CuO/α-MnO2catalyst modified with 3 wt% NiO and calcined at 400 °C exhibited the highest surface adsorbed oxygen content and the best normalized reaction rate, but the specific surface area limited its activity. Therefore, the appropriate loading of the Co3O4modifier could greatly enhance the activity of CuO/α-MnO2. This research could provide a reference method for constructing efficient low-temperature CO oxidation catalysts.Keywords:transition metal oxides;CuO-based catalysts;Co3O4modification;α-MnO2nanowire;catalytic oxidation of CO
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Cancer Nanotechnology
·
2023
·Vol. 14
·期 1
·1-19
·
IF 5.7
Wu Yueyao,Wang Runtian,Shen Peiliang,Zhou Weijia,Chen Chao,Yang Kaiyong,Yang Jingjing,Song Yujun,Han Xin,Guan Xiaoxiang
Cancer treatment by inducing tumor cell immunogenic cell death (ICD) is critical for tumor therapy. However, ICD activation by single pathway is often limited in practical application due to its low efficiency. In addition, the low pH and anoxic microenvironments in solid tumors greatly limit the effective activation of ICD. Herein, hollow manganese dioxide (H-MnO2) nanomaterials were selected to load both Mitoxantrone (MTZ) and Chlorin e6 (Ce6) due to its hollow structure and ability to release drugs in the acidic environments. Thus, the synergy of photodynamic therapy (PDT), photothermal therapy (PTT) and chemotherapy can induce the process of immunogenic cell death, stimulate the maturation of dendritic cells (DCs), and activate the immune response to kill tumor cells dramatically. Efficient immunotherapeutic effects were obtained when MnO2-C/M-HA was given intravenously to 4T1 tumor-bearing BALB/c mice with 660 nm near-infrared laser irradiation. This study overcame the limitations of monotherapy and provided a multifunctional platform for tumor immunotherapy.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Minghua He,Zulhumar Turup,Xuekun Jin,Fengjuan Chen
MnO 2 is considered to be one of the most promising electrocatalysts for oxygen reduction reactions (ORR) in alkaline media and can be applied to various electrochemical energy conversion and storage devices. However, it is limited by the relatively slow kinetics of the cathodic electrochemical reactions . In addition, it is difficult to control the presence state of Ag during the modification of MnO 2 . To this end, an efficient ORR electrocatalyst of Ag nanoparticles supported by MnO 2 nanorods was successfully synthesized by using NH 3 ·H 2 O as a complexing agent to inhibit the Ag + intercalating into the tunnels of MnO 2 . The half-wave potential ( E 1/2 ) and limiting current density ( J lim ) of the obtained Ag/MnO 2 electrocatalysts are 0.81 V and −5.6 mA cm −2 , respectively, showing comparable ORR catalytic activity to commercial Pt/C catalysts. The excellent catalytic performances can be attributed to the presence of abundant oxygen vacancies and Mn 3+ species on the MnO 2 surface, as well as the synergistic effect between MnO 2 substrates and Ag nanoparticles. Among them, oxygen vacancies enhances the adsorption of O 2 , Mn 3+ facilitates the displacement of O 2 2− /OH − , MnO 2 inhibits the accumulation of peroxide species to improving the oxygen environment on the Ag surface and Ag accelerates the electron transfer in the whole process. This work provides a useful guide for the design of efficient Mn-based ORR electrocatalysts.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 17
·51125-51142
·
IF 5.8
Lu Mang,Wu Xue-jiao,Wan Chu-xing,Gong Qiu-ping,Li Jia-xin,Liao Shuang-shuang,Wang Yu-an,Yuan Shu-hao
A reduced graphene oxide (RGO) supported Fe 3 O 4 -MnO 2 nanocomposite (Fe 3 O 4 -MnO 2 @RGO) was successfully prepared for catalytic degradation of oxytetracycline (20 mg/L) by potassium persulfate (PS) and adsorption removal of mixture of Pb 2+ , Cu 2+ , and Cd 2+ ions (each 0.2 mM) in the synchronous scenario. The removal efficiencies of oxytetracycline, Pb 2+ , Cu 2+ , and Cd 2+ ions were observed as high as 100%, 99.9%, 99.8%, and 99.8%, respectively, under the conditions of [PS] 0 = 4 mM, pH 0 = 7.0, Fe 3 O 4 -MnO 2 @RGO dosage = 0.8 g/L, reaction time = 90 min. The ternary composite exhibited higher oxytetracycline degradation/mineralization efficiency, greater metal adsorption capacity (Cd 2+ 104.1 mg/g, Pb 2+ 206.8 mg/g, Cu 2+ 70.2 mg/g), and better PS utilization (62.6%) than its unary and binary counterparts including RGO, Fe 3 O 4 , Fe 3 O 4 @RGO, and Fe 3 O 4 -MnO 2 . More importantly, the ternary composite had good magnetic recoverability and excellent reusability. Notably, Fe, Mn, and RGO could play a synergistic role in the improvement of pollutant removal. Quenching results indicate that surface bounded SO 4 •– was the major contributor to oxytetracycline decomposition, and the -OH groups on the composite surface shouldered a significant role in PS activation. The results indicate that the magnetic Fe 3 O 4 -MnO 2 @RGO nanocomposite has a good potential for removing organic-metal co-contaminants in waterbody. Graphical Abstract
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高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Tong Ding,Wenxiao Zhao,Yuqing Sun,Shilong Li,Tianxiang Yu,Wenheng Jing
In this work, a novel 2D Fe 3 O 4 -MnO 2 hollow fiber ceramic membrane (HFCM) with both excellent separation performance and high catalytic activity was constructed. The Fe 3 O 4 nanoparticles were deposited on 2D MnO 2 nanoplates to increase the Mn 3+ content, and then the nanoplates were pressure-driven and sintered on the surface of the hollow fiber ceramic supports to obtain 2D Fe 3 O 4 -MnO 2 -HFCMs. Electron spin resonance analysis confirmed that hydroxyl radicals and superoxide radicals played a major role in oxidative degradation and tetracycline hydrochloride (TCH) removal was 86.9 %. Noteworthily, TCH was concentrated on the membrane interface due to the concentration polarization effect, which increases the probability of binding free radicals from the catalytic membrane layer, thus enhancing the catalytic performance and the anti-fouling capability of the membrane. The 2D Fe 3 O 4 -MnO 2 -HFCM can be applied in wastewater treatment due to its superior catalytic ozonation activity and high separation performance.
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Biomaterials Science
·
2023
·Vol. 11
·期 6
·2243-2252
·
IF 6.6
Anni Cui,Ying Bao,Haitao Xu,Xin Mu,Xiahua Zhong,Wynn Wee,Fanqi Wu,Guiye Shan
The rapid emergence of drug-resistant bacteria has attracted great attention to exploring advanced antibacterial methods. However, single-modal antibacterial therapy cannot easily eliminate drug-resistant bacteria completely due to its low efficacy. Therefore, it is essential to achieve multi-modal antibacterial therapy effectively. Herein, a dual-modal ROS generator was designed based on photosensitive PDA–MnO2@Ce6/liposome (PMCL) nanozymes for synergistic chemo-photodynamic therapy. PMCL nanozymes adhere to bacteria through liposome–membrane fusion. Meanwhile, PMCL catalyzes endogenous hydrogen peroxide (H2O2) to generate hydroxyl radicals (˙OH) and singlet oxygen (1O2) under laser irradiation. Furthermore, the photothermal effect can accelerate the generation of ROS. Based on dual-enzyme activities (mimicking peroxidase and catalase) and photodynamic properties, PMCL achieves powerful antibacterial efficacy and mature bacterial biofilm eradication. With the synergistic chemo-photodynamic effects, bacterial populations decrease by >99.76% against Gram-positive S. aureus and Gram-negative E. coli. Notably, the synergistic antibacterial properties of PMCL nanozymes are further explored using a mouse wound model of S. aureus infection. This work fabricated an efficient dual-modal ROS generator to kill bacteria, further providing a new strategy for treating wound infection.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 47
·期 3
·1094-1104
·
IF 3.925
Hui Luo,Yang Han,Kaiyuan Hu,Jia Li,Dickon H. L. Ng,Xiaodi Ma,Kairui Luan,Mingkang Yang
Herein, we demonstrate a novel Fe3O4@MnO2@HKUST-1 magnetic micromotor with excellent peroxidase-like activity for highly efficient colorimetric detection and degradation of hydroquinone. Such micromotors had unique flower-like morphology with highly exposed active sites. The resulting MnO2-based micromotor was propelled by O2 bubbles generated from hydrogen peroxide fuel catalyzed by MnO2, and the velocity could be adjusted by the H2O2 fuel concentration. The self-propelled motion of the Fe3O4@MnO2@HKUST-1 could effectively increase the collision probability between active sites and pollutant molecules, and thus, enhanced the sensitivity of the colorimetric detection as well as the degradation efficiency. These excellent results confirm that this Fe3O4@MnO2@HKUST-1 micromotor has good prospects for future use in water treatment applications.
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