ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Yan Zhang,Ming-Ming Gao,Xin-Hua Wang,Shu-Guang Wang,Rui-Ting Liu
An electro-Fenton process was developed for wastewater treatment in which hydrogen peroxide was generated in situ with a rotating graphite disk electrode as cathode. The maximum H 2 O 2 generation rate for the RDE reached 0.90 mg/L/h/cm 2 under the rotation speed of 400 rpm at pH 3, and −0.8 V vs SCE. The performance of this electro-Fenton reactor was assessed by tetracycline degradation in an aqueous solution. Experimental results showed the rotation of disk cathode resulted in the efficient production of H 2 O 2 without oxygen aeration, and excellent ability for degrading organic pollutants compared to the electro-Fenton system with fixed cathode. Tetracycline of 50 mg/L was degraded completely within 2 h with the addition of ferrous ion (1.0 mM). The chronoamperometry analysis was employed to investigate the oxygen diffusion on the rotating cathode. The results demonstrated that the diffusion coefficients of dissolved oxygen is 19.45 × 10 −5 cm 2 /s, which is greater than that reported in the literature. Further calculation indicated that oxygen is able to diffuse through the film on the rotating cathode within the contact time in each circle. This study proves that enhancement of oxygen diffusion on RDE is benefit for H 2 O 2 generation, thus provides a promising method for organic pollutants degradation by the combination of RDE with electro-Fenton reactor and offers a new insight on the oxygen transform process in this new system.
研究领域:
环境科学
·
电化学
·
水处理技术
·
污染物降解
·
反应工程
✓ 已验证
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2024
·
IF 4.8
Shuai Ma,Di Dong,Mengyao Zhang,Ye Gao,Zhuangzhi Wu,Dezhi Wang
W-Re-HfC alloys have been extensively applied in the field of high-temperature structural parts. To ensure high temperature reliability, it is essential to enhance creep resistance ability. In this study, the microstructures of forged W-Re-HfC alloys were adjusted using different heat treatment processes . The corresponding tensile creep properties were also measured at 2000 °C with 40 MPa. Furthermore, a possible creep fracture mechanism was also explored. The forged W-Re-HfC sample annealed for 2 h exhibited the best creep performances with a steady-state creep rate of 3.28 × 10 −6 and a creep life of 5.6 h. Generally, a larger grain size indicates a lower steady-state creep rate; however, the precipitation of carbides at the grain boundaries (GBs) deteriorates the bonding strength of interfaces, thus reversing the former trend. The dominant creep mechanism is diffusion creep , in which the voids nucleate perpendicular to the GBs, grow and connect into cracks, ultimately leading to fractures.
研究领域:
材料科学
·
金属学与热处理
·
高温结构材料
·
固态物理
·
力学性能
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Zhao Li,Baorang Li,Xiaoze Du,Hongwei Wu
It is recognized that the thermal performances of the molten salt based nanocomposite can be significantly enhanced. However, there were rare investigations regarding its stability under practical operating thermal environments . In this study, both of the specific heat capacity and thermal diffusivity of the molten salt based nanocomposite were experimentally evaluated under various operating conditions, including that of exposure to constant high temperature and low-high temperature circulation. The typical solar salt based nanofluid was prepared via the modified two-step method. The selected nanoparticle was SiO 2 with an average diameter of 30 nm. Experimental results indicated that both the heat treatments could significantly decrease the thermophysical properties , which would result in poor thermal stability. In comparison with the samples exposing to constant high temperature, the thermal cycled samples showed a more stable thermal property. Further investigations on the SiO 2 particle morphology transition in the process of the heat treatments revealed that the impact of both temperature field and natural convection on particle agglomeration should be responsible for the decrease in thermophysical properties of nanofluid.
研究领域:
材料科学
·
热物理学
·
能源工程
·
纳米科技
·
化学工程
✓ 已验证
DOI
高影响因子
Green Energy & Environment
·
2020
·Vol. 7
·期 1
·53-65
·
IF 6.395
Hong-Li Ding,Hai-Tao Yu,Xiao-dong Wang,Chen-Feng Guo,Bing Zheng,Ying Xie,Ting-Feng Yi
SrLi 2 Ti 6 O 14 (SLTO) coated with different amount of ZrO 2 was successfully prepared. The as-obtained composites are stacked by a series of particles with a pure phase structure and a good crystallinity. Furthermore, ZrO 2 coating not only enhances the structural stability of the materials but also facilitates the diffusion of lithium through the SEI film. As a result, the redox polarization was reduced, and the reversibility of the electrochemical reaction was enhanced. Particularly, SLTO-ZrO 2 -2 sample delivers a high initial lithiation capacity of 283.6 mA h g −1 , and the values maintain at 251.7, 228.0, 207.4, 175.3, and 147.7 mA h g −1 at the current densities of 0.13, 0.26, 0.54, 1.31, and 2.62 A g −1 , respectively. Our experiment also confirmed that SLTO materials coated with ZrO 2 are suitable for high power density applications, and the lithiation specific energy efficiency of SLTO-ZrO 2 -2 is 200% as high as that of pure SLTO at a power density of 1257 W kg −1 .
研究领域:
材料科学
·
电化学
·
能源存储
·
无机非金属材料
·
固态离子学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 87
·70743-70748
·
IF 3.84
Zhiwei Liu,Ping Li,Fuqiang Zhai,Qi Wan,Alex A. Volinsky,Xuanhui Qu
Nanostructured tungsten carbide with high surface area and containing amorphous carbon is prepared by a low temperature combustion synthesis method. The nanostructured tungsten carbide is used as the catalyst in a gas diffusion electrode. The obtained WC with different carbon content was investigated by XRD, FESEM, TG-DTA, BET and XPS. When the molar ratio of C/W is 19/3, the WC particles with different carbon content are obtained after a carbonizing process between 900 and 1400 °C, and the content of free carbon in WC also increases gradually with temperature. The carbon content is tested by the high frequency combustion-infrared absorption method in a carbon sulfur analyzer. The electrochemical properties of the tungsten carbide for the oxygen reduction reaction are characterized by its polarization curves and electrochemical impedance. The results show that the presence of the appropriate amorphous carbon is beneficial for improving the conductivity and dispersibility of the tungsten carbide catalyst, and more active centers can be provided by the catalyst.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
·
表面科学
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2019
·
IF 2.781
Yunjiao Li,Shilei Wang,Yongxiang Chen,Tongxing Lei,Shiyi Deng,Jie Zhu,Jinping Zhang,Jia Guo
Cadmium oxides (CdO), an important semiconductor material , have many superior properties when used as a cathode material for nickel-cadmium batteries. Here, the coating and the doped co-modified LiNi 0.8 Co 0.15 Al 0.05 O 2 cathode are constructed by a continuous wet chemical process and a high-temperature sintering process, wherein the Cd 2+ are uniformly doped in a gradient form and the CdO protective layer is distributed on the outer surface of secondary particles. The Cd-modified NCA material has more stable interfacial and crystal lattice structure, thereby inhibiting harmful phase transitions and side-reactions. Accordingly, the modified sample has excellent electrochemical performance and maintaining a complete spherical morphology during long cycling compared to the pristine sample. In addition, as a pillar ion, cadmium increases the plate spacing and lithium-ion diffusion kinetics. The electrochemical results show that the capacity retention of the modified sample Cd-2000 reached 96.5% and 90.6% after 100 cycles and 200 cycles respectively at 1 C. At the high current rate of 8 C, the initial capacity and retention (100 cycles, 3.0–4.3 V) reach 166.2 mAh g −1 and 95.2%, respectively. Besides, the results of electrochemical impedance spectroscopy (EIS) reveal that CdO modification could decrease the resistance of the cell polarization and impedance increment upon cycling.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
半导体材料
✓ 已验证
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2018
·
IF 5.123
Feng Tan,Xiao Jiang,Xianliang Qiao,Daming Sun,Jinsuo Gao,Xie Quan,Jingwen Chen,Suyu Ren,Yi Wang
A diffusive gradients in thin films (DGT) method using a new high-capacity cerium oxide (CeO 2 ) binding gel, for the first time, was developed for measuring dissolved inorganic arsenic in freshwater and seawater . The capacities of the new CeO 2 binding gel were 682 μg and 375 μg for As III and As V , respectively. The masses of As III and As V accumulated by CeO 2 -DGT device increased linearly with time and agreed well with the theoretical value calculated by DGT equation. The arsenic accumulation by CeO 2 -DGT was independent of pH (4.05–9.04) and ionic strength (0.1–750 mM), and common anions including CO 3 2− , SO 4 2− , Cl − and PO 4 3− had no obvious interference. CeO 2 -DGT showed excellent long-term deployment performance in freshwater and synthetic seawater . Field trials with CeO 2 -DGT achieved successfully the time-weighted-average concentrations of total inorganic arsenic in reservoir water (1.38 ± 0.09 μg/L) and coastal seawater (0.45 ± 0.06 μg/L). The results were comparable to those measured by grab sampling. The proposed method was reliable and robust for in-situ measurements of dissolved inorganic arsenic in environmental waters.
研究领域:
环境化学
·
分析化学
·
水环境监测
·
环境地球化学
·
污染生态学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 49
·期 3
·4863-4871
·
IF 5.532
Kai Su,Xuekun Tian,Zhenzhen Li,Xinhong Liu
Biochar was proposed as a novel carbon source for synthesizing Ti 3 SiC 2 powder with high purity by a simple pressureless sintering at 1673 K, and Ti 3 SiC 2 grains exhibited the typical nanolayered structure. The oxidation behavior of Ti 3 SiC 2 powder showed the parabolic law during isothermal oxidation from 1273 K to 1473 K. Dense and continuous oxidation layer consisting of mixed TiO 2 and SiO 2 was formed rapidly on the surface of Ti 3 SiC 2 particles as a diffusion barrier , which effectively retarded the inward diffusion of oxygen, conferring good oxidation resistance of the powder.
研究领域:
材料科学
·
无机非金属材料
·
高温材料
·
复合材料
·
材料化学
·
固体化学
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Liying Xian,Min Li,Daping Qiu,Chuang Qiu,Cheng Yue,Feng Wang,Ru Yang
Layered P-type structures are integral to most competitive cathodes for sodium-ion batteries (SIBs). However, the performance of P2-type cobalt-based layered materials is unsatisfactory owing to a low initial discharge capacity caused by Na deficiency. Here, Mn-doped Na x CoO 2 with a P3 structure is synthesized by using a modified solvent-thermal method with calcination . A structural analysis shows that partial Mn doping can effectively control P3 phase formation and increase d -layer spacing, thereby improving the diffusion of Na + . In addition, enhanced electrochemical performance is observed in optimized P3-type Na 0.26 Co 0.48 Mn 0.52 O 2 (NCMO-1), which exhibits a reversible specific capacity of 64 mAh g −1 at 3 A g −1 and a good capacity retention of 58% after 500 cycles. Furthermore, the Na-ion full cell constructed with an NCMO-1 cathode and a hard carbon anode yields a competitive energy density of 175.9 Wh kg −1 at 0.4 A g −1 with excellent cycle stability. Thus, this work provides a new viewpoint on the development of P3 structural materials with higher electrochemical performance for SIBs.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
Small
·
2019
·Vol. 15
·期 50
·1904854
·
IF 10.856
Junchao Zheng,Zhuo Yang,Alvin Dai,Linbo Tang,Hanxin Wei,Yunjiao Li,Zhenjiang He,Jun Lu
Although the high energy density and environmental benignancy of LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) holds promise for use as cathode material in Li-ion batteries, present low rate capabilities, and fast capacity fade limit its broad commercial applications. Here, it is reported that surface modification of NCA cathode ( R-3m ) with 5 nm-thick nanopillar layers and Fm-3m structures significantly improves electrode structure, morphology, and electrochemical performance. The formation of nanopillar layers increases cycling and working voltage stability of NCA by shielding the host material from hydrofluoric acid and improves structural stability with the electrolyte. The modified NCA cathode exhibits an enhanced 89% capacity retention at a rate of 1 C over that of pristine NCA (75.2%) after 150 cycles and effectively suppresses working voltage fade (a drop of 0.025 V after 300 cycles) during repeated charge–discharge cycles. In addition, the diffusion barrier of Li ions in NCA crystals at 0.80 V is noticeably smaller than that of Li ions in pristine NCA (0.87 eV). These findings demonstrate that this unique surface structure design considerably enhances cycle and rate performance of NCA, which has potential applications in other Ni-rich layered cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
锂离子电池
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2017
·
IF 2.726
Ying Zhang,Xinxin He,Yutian Chen,Maogang He
The mutual diffusion coefficients of n -butanol + n -heptane and n -pentanol + n -heptane were measured over the mass fraction of n -butanol or n -pentanol from 0.05 to 0.95 at intervals of 0.10 and the temperatures 288.15 K, 298.15 K, 308.15 K and 318.15 K at 0.101 MPa. The measurements were carried out using a digital holographic interferometry system. The expanded relative uncertainty of the mutual diffusion coefficients was estimated to be less than 2.4%. The influences of temperature and composition on the mutual diffusion coefficients were investigated. Moreover, equations for the mutual diffusion coefficients of the two binary mixtures were fitted to the data as functions of mass fraction and temperature. The correlations represent the data with the absolute average of relative deviations (AARDs) of 1.1% for n -butanol + n -heptane and 0.77% for n -pentanol + n -heptane, respectively.
研究领域:
物理化学
·
热力学
·
传递现象
·
溶液化学
·
流体混合物
✓ 已验证
DOI
高影响因子
Nano Energy
·
2019
·
IF 15.548
Xiaodong Li,Sheng Fu,Shiyu Liu,Yulei Wu,Wenxiao Zhang,Weijie Song,Junfeng Fang
Operational stability remains the foremost concern delaying the commercialization of perovskite solar cells (PSCs). Ions diffusion from iodine-rich perovskite layer to metal electrode is one main reason for the irreversible devices degradation. Here we introduce chemically crosslinked TMTA (trimethylolpropane triacrylate) at both bulk perovskite layer and perovskite/PCBM interface to suppress the ions diffusion toward electrode. The TMTA in perovskite layer suppresses ions migration along grain boundaries and TMTA at perovskite/PCBM interface blocks ions diffusion toward electrode, owing to its continuous network structure and chemically inert nature. Diffusion experiment, permeation experiment and resistive random-access memory (RRAM) investigation confirm the effectively blocked ions diffusion in PSCs with TMTA whether under heat, light or electric field conditions. The resulting PSCs exhibit 7-fold improvement in operational stability at elevated temperature of 60 °C, retaining ~80% of initial efficiency after maximum power point tracking for 1000 h under continuous illumination. The PSCs with TMTA also exhibit good thermal stability and retain over 90% of the initial efficiency after aging at 60 °C for 1000 h.
研究领域:
材料科学
·
光伏技术
·
纳米材料
·
能源化学
·
器件物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）