Arabian Journal of Chemistry
·
2022
·
IF 6.212
Run Yuan,Yihe Qin,Can He,Zichen Wang,Lu Bai,Hong Zhao,Zijian Jiang,Lingyao Meng,Xuwen He
It is important to develop a catalyst that has high catalytic activity and can improve the degradation efficiency of refractory organic pollutants in the catalytic ozonation process. In this study, Fe-Mn-Cu-Ce/Al 2 O 3 was synthesised via impregnation calcination for catalytic ozonation of bio-treated coking wastewater. The physical and chemical characteristics of the catalysts were analysed using X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller nitrogen adsorption–desorption methods. The effects of catalyst dosage, pH, and reflux ratio on the degradation efficiency of wastewater were examined in laboratory-scale experiments. The chemical oxygen demand (COD) removal rate of bio-treated coking wastewater was estimated to be 52.76 % under optimal conditions. The experiments on the catalytic mechanism demonstrated that the surface hydroxyl formed by the Lewis acid sites on the surface of the catalyst can react with ozone as the active site forming the active oxygen (·OH, ·O 2 – , and 1 O 2 ), thereby efficiently degrading the organic pollutants in coking wastewater. Furthermore, a pilot-scale experiment on the catalytic ozonation of bio-treated coking wastewater was carried out using an Fe-Mn-Cu-Ce/Al 2 O 3 catalyst, while the effects of the initial pollutant concentration, ozone concentration, and gas flow on the COD removal rate were studied on a pilot scale. It was found that the COD removal rate of the wastewater was ∼ 60 % under optimal parameters. After the treatment, the wastewater steadily reached the coking wastewater discharge standard (COD < 80 mg/L), while the operating cost of catalytic ozonation reached ∼ 0.032$/m 3 , thereby paving the way toward economic engineering applications. The COD degradation kinetics in the bio-treated coking wastewater followed pseudo-second-order kinetics. Three-dimensional fluorescence and gas chromatography–mass spectrometry revealed that macromolecular organic pollutants in the bio-treated coking wastewater were greatly degraded. In summary, Fe-Mn-Cu-Ce/Al 2 O 3 exhibited good reusability, high catalytic activity, and low cost and has a wide application prospect in the treatment of coking wastewater.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Lin Sun,Yu Liu,Qingjun Yang,Fangrong Yan,Xiaoying Liu,Changhong Wang,Runmei Luo,Weidong Shi
Exploiting the theoretical capacity of transition-metal selenide (TMSe) electrodes with improving stability is a challenge in hybrid supercapacitors (HSCs). An in-situ strategy of multidirectional recombination of reasonable/stable hierarchical structure and multiphase synergy is proposed to boost TMSe electrodes to a higher level. Herein, trimetallic layered double hydroxides (CoNiMn-LDH) are in-situ reconstructed with hollow CNFs (carbon–nitrogen frameworks), which can expose numerous active sites and facilitates rapid charge transport. After systematic selenization (time gradient), the valence-rich multiphase (Co, Ni, Mn)-Se@CNFs is regulated and the hierarchical structure is further optimized with reduction of layer spacing for rapid charge transfer and OH – adsorption. The multiphase coordinated electrode demonstrates a high capacity (334.7 mAh g −1 , 1 A g −1 , 6 M KOH) and superior rate capability (277.8 mAh g −1 , 10 A g −1 , 83.0%). Besides, the assembled HSC demonstrates a quite high energy density ((Co, Ni, Mn)-Se@CNFs//Activated carbon, 91.6 Wh kg −1 at 800 W kg −1 ). The ultra-high cycle retention rate (without attenuation, 16,000 cycles) illustrates the excellent stability, which is superior to the HSCs we know that use TMSes. The in-situ strategy with systematic research on structure/phase regulation provides effective ideas for the preparation and application of high-capacity electrodes and high-efficiency HSCs.
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高影响因子
Small
·
2022
·Vol. 18
·期 13
·2106863
·
IF 15.153
Jie Huang,Yeqing Chen,Pengpeng Rao,Zongming Ni,Xueying Chen,Jie Zhu,Chen Li,Gaoyang Xiong,Ping Liang,Xin He,Songnan Qu,Jun Lin
Carbonized polymer dots (CPDs) have received tremendous attention during the last decade due to their excellent fluorescent properties and catalytic performance. Doping CPDs with transition metal atoms accelerates the local electron flow in CPDs and improves the fluorescent properties and catalytic performance of the CPDs. However, the binding sites and the formation mechanisms of the transition-metal-atom-doped CPDs remain inconclusive. In this work, Mn 2+ -ion–doped CPDs (Mn-CPDs) are synthesized by the hydrothermal method. The Mn 2+ ions form Mn O bonds that bridge the sp 2 domains of carbon cores and increases the effective sp 2 domains in the Mn-CPDs, which redshifts the fluorescence emission peak of the Mn-CPDs slightly. The Mn 2+ ions form covalent bonds in the CPDs and remedy the oxygen vacancies of the CPDs, which cuts off the non-radiative–recombination process of the Mn-CPDs and increases the quantum yield of the Mn-CPDs to 70%. Furthermore, the Mn O bonds accelerate the electron flow between adjacent sp 2 domains and enhances the electron transport in the Mn-CPDs. Thus, the Mn-CPDs demonstrate excellent catalytic performance to activate hydrogen peroxide (H 2 O 2 ) and produce hydroxyl radicals (•OH) to degrade methylene blue (MB) and rhodamine B (RhB).
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高影响因子
Journal of Materiomics
·
2021
·
IF 6.425
Yang Yin,Jing-Ru Yu,Yu-Cheng Tang,Ai-Zhen Song,Huan Liu,Dong Yang,Jing-Feng Li,Lei Zhao,Bo-Ping Zhang
NaNbO 3 -based ceramics usually show ferroelectric-like P-E loops at room temperature due to the irreversible transformation of the antiferroelectric orthorhombic phase to ferroelectric orthorhombic phase, which is not conducive to energy storage applications. Our previous work found that incorporating CaHfO 3 into NaNbO 3 can stabilize its antiferroelectric phase by reducing the tolerance factor ( t ), as indicated by the appearance of characteristic double P-E loops. Furthermore, a small amount of MnO 2 addition effectively regulate the phase structure and tolerance factor of 0.94NaNbO 3 -0.06CaHfO 3 (0.94NN-0.06CH), which can further improve the stability of antiferroelectricity. The XRD and XPS results reveal that the Mn ions preferentially replace A-sites and then B-sites as increasing MnO 2 . The antiferroelectric orthorhombic phase first increases and then decreases, while the t shows the reversed trend, thus an enhanced antiferroelectricity and the energy storage density W rec of 1.69 J/cm 3 at 240 kV/cm are obtained for 0.94NN-0.06CH-0.5%MnO 2 (in mass fraction). With the increase of Mn content to 1.0 % from 0.5 %, the efficiency increases to 81 % from 45 %, although the energy storage density decreases to 1.31 J/cm 3 due to both increased tolerance factor and non-polar phase.
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高影响因子
Polymers
·
2022
·Vol. 14
·期 24
·5417
·
IF 4.967
Shaoju Jian,Yuhuang Chen,Fengshuo Shi,Yifei Liu,Wenlong Jiang,Jiapeng Hu,Xiaoshuai Han,Shaohua Jiang,Weisen Yang
The occurrence of fluoride contamination in drinking water has gained substantial concern owing to its serious threat to human health. Traditional adsorbents have shortcomings such as low adsorption capacity and poor selectivity, so it is urgent to develop new adsorbents with high adsorption capacity, renewable and no secondary pollution. In this work, magnetic electrospun La-Mn-Fe tri-metal oxide nanofibers (LMF NFs) for fluoride recovery were developed via electrospinning and heat treatment, and its defluoridation property was evaluated in batch trials. Modern analytical tools (SEM, BET, XRD, FTIR) were adopted to characterize the properties of the optimized adsorbent, i.e., LMF11 NFs with a La:Mn molar ratio of 1:1. The surface area calculated via BET method and pHpzcassessed using pH drift method of LMF11 NFs were 55.81 m2g−1and 6.47, respectively. The results indicated that the adsorption amount was highly dependent on the pH of the solution, and reached the highest value at pH = 3. The kinetic behavior of defluoridation on LMF11 NFs was dominated by the PSO model with the highest fitted determination coefficients of 0.9999. Compared with the other three isotherm models, the Langmuir model described defluoridation characteristics well with larger correlation coefficients of 0.9997, 0.9990, 0.9987 and 0.9976 at 15 °C, 25 °C, 35 °C and 45 °C, respectively. The optimized LMF11 NFs exhibited superior monolayer defluoridation capacities for 173.30–199.60 mg F−/g at pH 3 at 15–45 °C according to the Langmuir isotherm model. A thermodynamic study proved that the defluoridation by LMF11 NFs is a spontaneous, endothermic along with entropy increase process. In addition, the LMF11 NFs still showed high defluoridation performance after three reused cycles. These findings unveil that the synthesized LMF11 NFs adsorbent is a good adsorbent for fluoride remediation from wastewater owing to its low cost, high defluoridation performance and easy operation.Keywords:La-Mn-Fe tri-metal oxides nanofibers;defluoridation;electrospinning;kinetics;wastewater treatment
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高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 25
·8502-8506
·
IF 7.059
Lu Hou,Yihua Zhu,Jingrun Zhu,Yiqin Gong,Chunzhong Li
Mn-doped 2D perovskite powders are promising phosphors for warm white light-emitting diodes (LEDs). However, it remains a challenge to solve the problem of lead toxicity and improve the photoluminescence quantum yields (PLQYs). Here, we have successfully prepared Mn-doped 2D Sn-based perovskite materials ((C8H17NH2)2Sn1−xMnxBr4). The PLQYs of (C8H17NH2)2Sn1−xMnxBr4 (x = 0.26) powders reach up to 42%. The as-prepared (C8H17NH2)2Sn1−xMnxBr4 exhibits a single broad photoluminescence (PL) band, differing from the dual peaks of Mn-doped lead halide perovskite quantum dots. Theoretical conclusions and experimental results show the competitive relationship between self-trapped exciton (STE) emission from the host crystal and dopant Mn d–d transition emission. With increasing Mn dopant concentration, the PL spectra exhibit red shifts and the full width at half-maximum (FWHM) becomes larger, which is constructive for warm white LEDs. The fabricated warm white LEDs based on (C8H17NH2)2Sn1−xMnxBr4 show a warm white light correlated color temperature (CCT; 3542 K) and a high color-rendering index (Ra, 88.12). Our work provides new possibilities for optoelectronic devices based on lead-free perovskite materials.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Zhiping Yan,Xin Wang,Ruiding Fei,Ruixue Zhu,Jianfeng Zhao,Wenchao Wang
Developing a highly effective solar-to-H 2 conversion system is a promising strategy for carbon neutrality. Here, we report a chemically bonded Z-scheme photocatalyst by specifically linking the conduction band site of ZnIn 2 S 4 with the valence band site of Mn 0.3 Cd 0.7 S 1-x . Deviates from the typical van der Waals interactions between two semiconductors, the in-built robust binding force (Mn-S bond) and charge transfer channel facilitates the electron mobility, minimizes detrimental deep charge trapping, and prolongs the active charge lifetime from 983 ps to 4250 ps. The sulfur vacancies in Mn 0.3 Cd 0.7 S 1-x are partially refilled by atoms of the same element in ZnIn 2 S 4 during the in-situ formation of heterojunctions, which promotes and solidates the establishment of interfacial chemical bonds. The optimal photocatalyst achieves a high quantum efficiency of 32.71 % at 420 nm. This study offers a new insight into the development of Z-Scheme heterojunctions via a synergistic approach involving doping, vacancy filling and strong interfacial chemical bonds.
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高影响因子
Catalysts
·
2026
·Vol. 16
·期 10
·891
·
IF 4.5
Tianyi Sheng,Xiaodan Zhang,Jiaxin Ma,Yanguang Chen
Coke deposits on the inner walls of furnace tubes during the steam cracking process can significantly reduce heat transfer efficiency and ethylene yield. This study designed a series of Co-Mn-based perovskite catalysts with tunable molecular structures, morphologies, and pore structures to achieve in situ and efficient coke removal. This research evaluated the catalytic performance of these catalysts as coke models in the graphite gasification reaction. The optimal synthesis parameters for SrCo1−xMnxO3(SCM-x) were determined through the sol–gel method. Specifically, the Mn doping content was x = 0.1, citric acid was used as the complexing agent, pH = 3, and calcination was performed at 800 °C, which produced a cubic perovskite structure with a porous, flake-like morphology. Under the optimized reaction conditions (catalyst and graphite particle sizes of 140–150 and 160–180 mesh, 900 °C, 10 wt.% catalyst loading, water flow 0.167 mL·min−1, 120 min), SCM-0.1 achieved a graphite conversion of 64.78%, which around 18 times higher than that without catalyst. The results of XRD, XPS, H2O-TPD, in situ DRIFTS, SEM, and UV analyses revealed that Mn doping increased oxygen vacancy concentration, enhanced oxygen mobility and bound-water adsorption, and promoted the formation of ·OH radicals from water vapor, which effectively accelerates the gasification of graphite. These findings demonstrate the potential of Mn-doped SrCoO3perovskites as an anti-coking coating material for ethylene cracking furnaces.
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高影响因子
DESALINATION
·
2024
·
IF 8.3
Xuehan Xiao,Zongxue Yu,Juan Wang,Shiyi Luo,Yan Huang,Dingmei Han,Junchen Li,Zhiquan Chen,Jie Wang,Minggang Huang
The long-term and efficient treatment of shale gas wastewater is an inevitable tendency. This study employed the SEP@Fe-Mn/RGO composite membrane series for the membrane separation treatment of shale gas wastewater. Different proportions and different function of SEP@Fe-Mn/RGO composite membranes were obtained through the method of electrostatic self-assembly. This study researched the “Trade-off” issue of membranes separation through the analysis,resulting in membranes that best meets the separation requirements for shale gas wastewater. After two membrane separation, The oil-water separation efficiency (COD 2040 mg/L and TOC 487.14 mg/L) of shale gas wastewater was >99.3 %. The removal rate of the main salt component (Na 2 SO 4 ) reached 83.56 %, and the removal rate of major heavy metal ions (Fe 3+ , Cr 3+ , Ba 2+ ) was above 60 %. Because of the continuous generation of in-situ bubbles by the reaction of MnO 2 with H 2 O 2 , and Fenton reactions on the membrane, which further accelerated the separation of pollutants. In a variety of harsh water environments, this membrane series remained stable within 12 h. Simple to prepare, cost-effective, low in energy consumption, and environmentally friendly, which makes it promising for wide applications in the field of petroleum water treatment.
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2025
·
IF 3.8
Shuangjiang He,Junchang Wang,Chong Wang,Xiao Zhang,Sen Liang
The Mn-Fe-Co-Zn-O series is a widely used thermistor material, but its thermal stability is compromised by nitrogen glass encapsulation, limiting its application in electrical devices. To address this issue, La 2 O 3 and Y 2 O 3 were used as rare earth oxide dopants, and xR 2 O 3 -Mn 0.76 Fe 0.87 Co 1.07 Zn 0.3 O 4 (x = 0.0025, 0.005, 0.01, 0.02) negative temperature coefficient (NTC) materials were synthesized via solid-state sintering. The effect of rare earth doping on the electrical properties after high-temperature nitrogen annealing was investigated. After annealing at 750°C for 4 h, the variation in resistivity ( ρ 25 ) and material constant ( B 25/50 ) significantly decreases with increasing La doping. For the La-doped sample (x = 0.01), Δρ 25 decreased to 7.77% and ΔB 25/50 to 0.77% (for the Y-doped sample (x = 0.01), Δρ 25 decreased to 22.76% and ΔB 25/50 to 1.91%), compared to the undoped sample, where Δρ 25 reduced by 168.84% and ΔB 25/5 0 by 5.57%. This improvement was attributed to rare earth accumulation at grain boundaries, filling voids and forming R-O bonds, which inhibited oxygen vacancy migration and significantly reduced grain boundary resistance. Rare earth doping effectively improved the thermal stability and electrical consistency of NTC thermistor ceramics in high-temperature nitrogen atmospheres, offering a new strategy for high-temperature encapsulation applications. (Y-doped samples showed similar results, as detailed in the Supplementary Materials.)
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Yadong He,Shi Tang,Mengting Hua,Pi Wang,Yuandong Li,Rao Fan,Ling Li
n dye-sensitized solar cells (DSSCs), the counter electrodes (CEs) functions both as an electron collector from the peripheral circuitry and as a catalytic platform for regenerating the redox couple (I − /I 3 − ) in the electrolyte. Although Pt offers excellent catalytic activity, its high cost and instability limit practical use. Transition metal oxides are promising Pt alternatives but have low conductivity and inadequate catalytic performance. Here, we synthesized a cactus-like Mn-Co-Ni oxide composite on carbon paper (MnCoNiO/CP) via a two-stage process combining hydrothermal treatment with subsequent annealing. The hierarchical structure provided a high specific surface area (67.753 m 2 ·g −1 ), abundant active sites, and enhanced conductivity. The MnCoNiO/CP-based DSSCs exhibited a photovoltaic performance characterized by an open-circuit voltage (V oc ) of 0.807 V, short-circuit current density (J sc ) reaching 17.86 mA·cm −2 , and fill factor (FF) attaining 0.7, culminating in an overall power conversion efficiency (PCE) of 10.04 %. This corresponds to a 34.8 % enhancement in PCE compared to the Pt electrode (7.45 %) under identical conditions. The performance improvement directly correlates with the unique cactus-like morphology and the synergistic effects of the multi-component oxides. This work introduces a cost-effective strategy for developing enhanced-functionality CEs in DSSCs and other applications.
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高影响因子
DIAMOND AND RELATED MATERIALS
·
2024
·
IF 4.3
Tian-Li Meng,Jia-Wei Wang,Ying-Xia Ma,Xin-Quan Chen,Lei Lei,Jing Li,Fen Ran
Layered double hydroxide (LDH), as an electrode material, consists of positively charged layers and interlayer hydrated anions and is endowed with promising prospects in supercapacitors (SCs) due to its large specific surface area, tunable metal ions, abundant redox active sites, and low cost. Moreover, metal-organic frameworks (MOFs) exhibit adjustable pore sizes, while multi-walled carbon nanotubes (MWCNTs) boast exceptional electrical conductivity. Hence, in this work, flower-like nickel/manganese layered double hydroxide (Ni/Mn-LDH) was introduced into nanohybrid of MWCNTs decorated with nickel metal-organic frameworks (Ni-MOFs/MWCNTs) to fabricate a novel Ni-MOFs/MWCNTs@Ni/Mn-LDH nanohybrid as electrode material for SCs using a two-step solvothermal method. In the composite structure of the novel Ni-MOFs/MWCNTs@Ni/Mn-LDH nanohybrid, the flower-like assembly of Ni/Mn-LDH nanosheets was seamlessly integrated with MWCNTs adorning the Ni-MOFs, creating an interconnected hierarchical porous network. This distinctive structure, coupled with the synergistic effects of its components, facilitated the swift diffusion of electrolyte ions. Furthermore, it enhanced the accessibility to more active sites at the interfaces during the redox process, thereby contributing considerably to an improved electrochemical performance. The specific capacity of the Ni-MOFs/MWCNTs@Ni/Mn-LDH nanohybrid as electrode material obtained at the optimal experimental conditions was 1151.0C g −1 at 1.0 A g −1 . The assembled asymmetric supercapacitor (ASC) had an energy density of 25.6 Wh kg −1 at a power density of 845.3 W kg −1 . The fabrication strategy of the Ni-MOFs/MWCNTs@Ni/Mn-LDH could be extended to synthesize other nanohybrid.
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高影响因子