INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Yushan Hou,Jianfang Wu,Elena Yu. Konysheva
Quantitative analysis of Cr-adsorption from a gas phase on CeO 2 , pure and doped BaCeO 3 was performed in combination with surface techniques and electrochemical impedance spectroscopy . The Cr-adsorption on BaCeO 3 is 3 times higher than on CeO 2 and it increases by 12–25% on In doping in Ba(Ce 1−x In x )O 3 (x = 0.1–0.3) in the temperature range of 600–700 °C. These perovskites adsorb chromium with the formation of a multi-phase surface layer containing BaCr 6+ O 4 and cerium oxide. Coexistence of small fractions of Cr 3+ and Cr 5+ cations in the surface layer was identified by X-ray photoelectron spectroscopy. The thickness of the surface layer and its morphology vary with temperature, affecting the conductivity of Ce containing perovskites below 700 °C. BaCrO 4 exhibits under air noticeably larger anisotropic thermal expansion than BaCeO 3 . The results indicate that high tolerance to Cr-gaseous species should be considered as an important criterion for further development of materials for proton-conducting SOFCs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2021
·
IF 5.03
Yiwei Long,Jian Gao,Zhuolin Cheng,Daoyuan Chen,Kangning Wu,Jianying Li,Fusheng Zhou
The skin-core structure of thermally aged epoxy resin consisting of the aged surface-layer and the unaged inner-layer, was studied in this paper. A new tan δ peak appeared in the results of dynamic mechanical analysis (DMA) after the specimens were thermally aged. It steadily diminished when the surface of the specimens was gradually removed, which indicates that the newly detected peak arose from formation of surface-layer during ageing. Thickness of the surface-layer could reach up to 0.09 mm after thermal ageing for 480 h. According to Fourier transform infrared spectroscopy (FTIR) results, formation of the surface-layer was found to closely correlated with thermal oxidation and re-crosslinking processes. The former induced oxidized molecular chains while the later might be related to the production of carboxylic acid dimers and etherification reactions to result in strengthened networks. This was further ascertained by the results of dielectric spectroscopy and isothermal surface potential decay (ISPD) tests. The relaxation process of aged epoxy resin displayed higher relaxation time, strength, and activation energy than unaged specimens, and evident growths of both deep and shallow level traps densities were also observed after thermal ageing. This casts new light on the thermal ageing mechanism of epoxy resin and could provide a feasible method for its insulation degradation assessment.
研究领域:
材料科学
·
电绝缘研究
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Jiuyang Xia,Fengping Zhang,Juli Liang,Kaixin Fang,Wenwei Wu,Xuehang Wu
Commercial Cu foam can be employed as a 3D current collector to accommodate Na metal for stable sodium metal batteries (SMBs). However, few studies focus on regulating the interphase structure and properties of Cu foam to achieve fast and uniform Na impregnation. Herein, a facile and controllable oxidation treatment strategy is used to in-situ construct a fluffy CuO/Cu 2 O surface layer on the skeleton of Cu foam (SF–Cu-3.6). The oxidation degree and interphase structure of Cu foam can be rationally designed by adjusting the concentration of (NH 4 ) 2 S 2 O 8 oxidant, which is directly related to the driving force of Na infusion. With an optimized interface, Na metal can be rapidly infused into SF-Cu-3.6 within 5 s and a structurally complete Na/SF-Cu-3.6 composite electrode with a flat surface and no visible void can be obtained. The SF-Cu-3.6 with a large surface area can be used as a 3D host for Na metal to lower the local current density during cycling, resulting in uniform Na deposition without dendrite formation and growth. In virtue of the structural advantages, the symmetric Na/SF-Cu-3.6 cell exhibits flat charge/discharge plateaus with a low overpotential of 12 mV and stable cycling up to 1000 h at 0.5 mA cm −2 . When paired with NaTi 2 (PO 4 ) 3 , the rate performance of the full cell using the Na/SF-Cu-3.6 composite anode is significantly better than that of the full cell using a bare Na anode.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2019
·Vol. 23
·期 5
·1621-1630
·
IF 2.531
Zhao Liu-Dan,Zhang Qian,Fan Jin-Bin,Yin Li-Qiang,Qi Peng-Wei,Yao Hong-Chang,Li Zhong-Jun
The search for efficient and powerful photoanode materials remains one of the toughest challenges in photoelectrochemical (PEC) water splitting because the oxygen evolution reaction on the photoanode is a rate-limiting process. On the other hand, the semiconductor/liquid interface is a key factor governing the water splitting efficiency due to its influence on charge separation and collection. Herein, we synthesized vertically aligned WO 3 nanosheet array (NS) films on fluorine-doped tin oxide (FTO), and followed by electroreduction for tuning the surface structure of WO 3 NSs. A disordered layer is formed on the surface of WO 3 NSs by controlling the external bias voltage and reduction time of electroreduction, and its thickness of the disordered layer varies with reduction time. The optimal WO 3 NSs with a 1.2 nm disorder layer thickness exhibit a remarkable photocurrent density of 1.07 mA cm −2 at 1.23 V vs reversible hydrogen electrode (RHE) under AM 1.5G illumination, which is 1.43 times of pristine WO 3 NSs. The results indicate that the electroreduction voltage and reduction time exert great influence on the formation of the surface disordered layer, and the optimized reduction conditions can enhance charge transfer and charge separation efficiency, substantially improving the PEC performance of WO 3 photoanode.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-11
·
IF 15.7
Suo Hao,Zhao Peihang,Zhang Xin,Guo Yang,Guo Dongxu,Chang Jiwen,Chen Jiangkun,Li Panlai,Wang Zhijun,Wei Hanlin,Zheng Weilin,Wang Feng
Lanthanide-doped nanocrystals are promising for photon frequency upconversion with substantial spectrum tunability. However, the utilization of the upconversion process has been constrained by low luminescence efficiency, which may further attenuate at elevated temperatures due to thermal quenching. Herein, we report a versatile strategy to boost upconversion luminescence across a wide temperature range by surface coordination of small organic molecules. Mechanistic investigations affirm that the organic surface layer passivates defects and isolates high-energy surface oscillators, thereby preventing the dissipation of excitation energy. The energy preserving effect becomes more prominent with increasing temperatures, especially in a humid environment. Accordingly, the upconversion emission of NaGdF 4 :Yb 3+ /Tm 3+ nanocrystals is substantially enhanced in the ambient environment after ligand coordination, accompanied by an additional emission augmentation with increasing temperature to 443 K. By leveraging this anomalous optical response to thermal stimuli, we further establish full-color thermochromic upconversion switching for advanced anti-counterfeiting and logic encryption technologies.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOM
·
2024
·
IF 2.1
Saleem Muhammad Farooq,Ashraf Ghulam Abbas,Javid Muhammad,Haleem Yasir A.,Haidry Azhar Ali,Farooq Sajid,Lei Ma,Bilal Muhammad,Habib Muhammad,Akhtar Muhammad Saeed,Khan Rashid,Wang Tianwu
Understanding the dielectric properties of materials in the THz frequency range is crucial for the advancement of THz devices. Despite their significance, the dielectric characteristics of zirconium carbide (ZrC) within this frequency range remain underexplored, in particular the impact of surface carbon and oxide layers typically found on carbide particles. While traditional studies mainly focus on particle size, this study emphasizes the pivotal role of particle morphology in determining dielectric properties. Milling was employed to increase the surface exposure of ZrC particles, which were initially covered with layers of carbon and oxides. The dielectric parameters, derived from experimental THz time-domain spectroscopy (THz-TDS) data, indicated that increased milling led to improved energy storage capabilities. This enhancement is attributed to increased electronic polarizability and charge disorder-induced ionic polarization due to the increased surface exposure. Furthermore, the dielectric properties displayed reduced dispersion after further milling attributed to the uniform particle sizes and shapes achieved through this process. Our findings underscore the critical influence of surface carbon and oxide layers on the dielectric properties of ZrC and similar carbide particles—an aspect often overlooked in studies that focus solely on particle size and shape, ignoring the distinct dielectric contributions of each surface layer.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2016
·
IF 6.333
Xin Ao,Zhaoyin Wen,Yingying Hu,Tian Wu,Xiangwei Wu,Qiming He
Nickel particles with different contents of Ni 3 S 2 surface layer were prepared for their application as cathode materials in Na/NiCl 2 batteries . The surface modification of nickel particles is found to prevent their growth and battery degradation during cycling. The optimum level of surface modification was determined by electrochemical tests and morphology characterization. Excessive Ni 3 S 2 layer seems to cause particle aggregation resulting in low reversible capacity. The capacity of the cell with optimum level of Ni 3 S 2 surface modification layer after 50 cycles is about 4 times greater than that without Ni 3 S 2 surface modification layer.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-12
·
IF 16.6
Liu Li-Juan,Alkan Fahri,Zhuang Shengli,Liu Dongyi,Nawaz Tehseen,Guo Jun,Luo Xiaozhou,He Jian
The advances in determining the total structure of atomically precise metal nanoclusters have prompted extensive exploration into the origins of chirality in nanoscale systems. While chirality is generally transferrable from the surface layer to the metal–ligand interface and kernel, we present here an alternative type of gold nanoclusters (138 gold core atoms with 48 2,4-dimethylbenzenethiolate surface ligands) whose inner structures are not asymmetrically induced by chiral patterns of the outermost aromatic substituents. This phenomenon can be explained by the highly dynamic behaviors of aromatic rings in the thiolates assembled via π − π stacking and C − H···π interactions. In addition to being a thiolate-protected nanocluster with uncoordinated surface gold atoms, the reported Au 138 motif expands the size range of gold nanoclusters having both molecular and metallic properties. Our current work introduces an important class of nanoclusters with intrinsic chirality from surface layers rather than inner structures and will aid in elucidating the transition of gold nanoclusters from their molecular to metallic states.
研究领域:
纳米材料科学
·
物理化学
·
材料化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Huizhang Zhao,Jianhui Lv,Xiao Ma,Bin Huang,Lei Han,Xingyu Kang,Dong Wang,Hairui Fang
NO 2 concentration in soil surface is one of the important indicators affecting soil nitrogen cycle. Real-time detection of NO 2 is crucial to optimize the use of nitrogen fertilizer and improve efficiency, which is also a key means to prevent soil acidification and increase crop yield. However, the humidity conditions on the soil surface increase the challenge of real-time detection of NO 2 . Therefore, a composite material of tungsten oxide (WO 3 ) composite tin sulfide (SnS 2 ) with heterogeneous structure was synthesized by one-step hydrothermal method. The composite material is seen to exist in the form of nanosheets. At the optimal working temperature of 210℃, the response of the composite material (WO 3 /SnS 2 (3:10)) with a molar ratio of WO 3 to SnS 2 of 3:10–20 ppm NO 2 is 63.8. The excellent gas sensing performance is attributed to the composition of heterojunction and the increase of deficiency oxygen. In the relative humidity (RH) range of 20–98 %, the response of the WO 3 /SnS 2 (3:10) has a good linearity ( R 2 =0.995). Therefore, the humidity compensation is integrated into the convenient NO 2 detection equipment to ensure that the WO 3 /SnS 2 (3:10) sensor can detect NO 2 stably and accurately under different humidity conditions. The NO 2 real-time detection system uses the OLED to display the humidity value and NO 2 concentration value in real time on the soil surface, and the buzzer as an alarm device for exceeding the concentration threshold (2 ppm NO 2 ), which reminds staff of the need to take action to adjust crop management strategies to improve crop health.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Pengfei Shen,Xiaolin Zhang,Hui Xu,Bingcai Pan
Surface complexation has long been recognized as the basic mode involved in fluoride adsorption onto metal oxides. However, such general recognition is challenged by the unusual pH dependence observed in fluoride adsorption. Here, we selected hydrated zirconium oxide (HZO) as a representative metal oxide to revisit the fluoride adsorption mechanism. Multiple in situ microscopic analyses and thermodynamic simulations suggest that, unlike the adsorption of other anions that proceed exclusively via substituting protonated terminal hydroxyl (η-OH2+) groups of metal oxides, fluoride can displace both η-OH2+ and protonated bridging hydroxyl (μ-OH+) groups of HZO (i.e., Substitution). This distinctive displacement drives the leaching of Zr from HZO, generating aqueous polyfluorozirconium complexes (i.e., Leaching) which subsequently deposit onto HZO via outer-sphere complexation (i.e., Deposition). The adsorbed polyfluorozirconium gradually converts into a fluorozirconate (Na5Zr2F13) coating, resulting in a surface layer reconstruction of up to 100 nm in depth. The atypical pH dependency of fluoride adsorption can be explained by the processes of Substitution, Leaching, and Deposition (i.e., SLD processes). More attractively, the SLD-driven surface layer reconstruction is reversible in nature, ensuring the constant defluoridation capability of HZO during cyclic adsorption-desorption assays. This study advances our understanding of fluoride adsorption at water-metal oxide interfaces.
研究领域:
环境科学
·
材料科学
·
界面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Langming Bai,Junwen Ding,Haorui Wang,Nanqi Ren,Guibai Li,Heng Liang
To overcome the permeability-selectivity limitation and improve the performance of desalination membranes, novel methods and design strategies are needed to prepare new types of thin film composite (TFC) nanofiltration (NF) membranes. In this work, a modified TFC membrane with a sandwiched layer and a surface layer was fabricated through a facile additional two-step approach. The microfiltration (MF) substrate and TFC surface were modified by a cellulose nanocrystal (CNC) sandwiched layer and a polydopamine (PDA) layer, respectively. Scanning electron microscopy (SEM) analysis indicated that the support modified by CNCs presented a more homogeneous surface than the control TFC. Cross-sectional SEM images showed that the underneath MF support, CNC interlayer, polyamide layer and PDA deposition layer were perfectly integrated. The surface charge was determined by an electrophoretic analyzer and revealed that the CNC interlayer increased the membrane electronegativity, while the PDA layer presented the opposite effect. Compared to the control TFC membrane, the solute permeability and rejection of the resultant CNC-TFC-PDA membrane were simultaneously increased, indicating a breakthrough in the trade-off limitation. The modified membranes exhibited a high removal rate for Congo red, Rose Bengal, sodium lignosulfonate and alkaline lignin, suggesting their excellent rejection performance for textile dyes and lignin derivatives. Fouling tests indicated that both the interlayer and surface layer exhibited positive effects on fouling alleviation. The effects of each functional layer were explored, and the main factors for performance improvement, including the modified hydrophilicity, surface charge, pore size and surface roughness , were discussed.
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
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2018
·Vol. 84
·期 9
·
IF 3.633
Peng Zhang,Jin-Song Guo,Peng Yan,You-Peng Chen,Wei Wang,You-Zhi Dai,Fang Fang,Gui-Xue Wang,Yu Shen
Pollutant degradation is present mainly in the surface layer of biofilms, and the surface layer is the most vulnerable to impairment by toxic pollutants. In this work, the effects of nanosized TiO2 (n-TiO2) on the average thicknesses of Bacillus subtilis biofilm and on bacterial attachment on different surfaces were investigated. The binding mechanism of n-TiO2 to the cell surface was also probed. The results revealed that n-TiO2 caused biofilm dispersal and the thicknesses decreased by 2.0 to 2.6 μm after several hours of exposure. The attachment abilities of bacteria with extracellular polymeric substances (EPS) on hydrophilic surfaces were significantly reduced by 31% and 81% under 10 and 100 mg/liter of n-TiO2, respectively, whereas those of bacteria without EPS were significantly reduced by 43% and 87%, respectively. The attachment abilities of bacteria with and without EPS on hydrophobic surfaces were significantly reduced by 50% and 56%, respectively, under 100 mg/liter of n-TiO2. The results demonstrated that biofilm dispersal can be attributed to the changes in the cell surface structure and the reduction of microbial attachment ability.IMPORTANCE Nanoparticles can penetrate into the outer layer of biofilm in a relatively short period and can bind onto EPS and bacterial surfaces. The current work probed the effects of nanosized TiO2 (n-TiO2) on biofilm thickness, bacterial migration, and surface properties of the cell in the early stage using the surface plasmon resonance waveguide mode. The results demonstrated that n-TiO2 decreased the adhesive ability of both cell and EPS and induced bacterial migration and biofilm detachment in several hours. The decreased adhesive ability of microbes and EPS worked against microbial aggregation, reducing the effluent quality in the biological wastewater treatment process.
研究领域:
环境科学
·
微生物学
✓ 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）