JOURNAL OF MEMBRANE SCIENCE
·
2013
·
IF 4.093
Qiang Xu,Yang Yang,Jie Yang,Xiaozu Wang,Zhaohui Wang,Yong Wang
Conformal and smooth TiO 2 thin layers were coated on the surface of porous PTFE membranes subjected to a plasma activation process by atomic layer deposition (ALD). In contrast, TiO 2 was deposited on the PTFE surface as globular particulates without plasma activation due to the inert chemical nature of PTFE surface. X-ray photoelectron spectrometry confirmed the formation of functional groups on the plasma-activated PTFE surface which served as active sites for the homogeneous adsorption and reaction of ALD precursors. Scanning and transmission electron microscopy revealed the uniformity of the deposited layer and the precise control of its thickness by changing ALD cycle numbers. The water contact angle measurement showed that the hydrophobic surface gradually turned to be near superhydrophilic with the increment of ALD numbers. Also, the membrane mean pore size was progressively reduced by simply altering the ALD numbers. At proper deposition conditions , the modified membranes gained an increase of pure water flux of more than 150% and simultaneously a doubled retention compared to the original unmodified membrane. This research provides an efficient approach devoid of any harsh treatments to modifying PTFE membranes for achieving specific functions, which also can be applied to other organic materials especially with chemical inert surface.
研究领域:
材料科学
·
膜科学与技术
·
表面工程
·
高分子化学
·
环境工程
·
纳米科技
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2021
·
IF 9.676
Pengfei Zhou,Jing Zhang,Zhennan Che,Zuhao Quan,Ju Duan,Xiaozhong Wu,Junying Weng,Jinping Zhao,Jin Zhou
P2-Na 0.67 Ni 0.33 Mn 0.67 O 2 is considered as a promising cathode material for sodium-ion battery (SIBs) because of its high capacity and discharge potential. However, its practical use is limited by Na + /vacancy ordering and P2-O2 phase transition. Herein, a Ti 4+ /F − co-doping strategy is developed to address these issues. The optimal P2-Na 0.67 Ni 0.33 Mn 0.37 Ti 0.3 O 1.9 F 0.1 exhibits much enhanced sodium storage performance in the high voltage range of 2.0–4.4 V, including a cycling stability of 77.2% over 300 cycles at a rate of 2 C and a high-rate capability of 87.7 mAh g −1 at 6 C. Moreover, the P2-Na 0.67 Ni 0.33 Mn 0.37 Ti 0.3 O 1.9 F 0.1 delivers reversible capacities of 82.7 and 128.1 mAh g −1 at −10 and 50 °C at a rate of 2 C, respectively. The capacity retentions over 200 cycles at −10 °C is 94.2%, implying more opportunity for practical application. In-situ X-ray diffraction analysis reveals that both P2-O2 phase transitions and Na + /vacancy ordering is suppressed by Ti 4+ /F − co-doping, which resulting in fast Na + diffusion and stable phase structure. The hard carbon//P2-Na 0.67 Ni 0.33 Mn 0.37 Ti 0.3 O 1.9 F 0.1 full cell exhibits a high energy density of 310.2 Wh kg −1 and remarkable cyclability with 82.1% retention after 300 cycles at 1 C in the voltage range of 1.5–4.2 V. These results demonstrate that the co-doping Ti 4+ /F − is a promising strategy to improve the electrochemical properties of P2-Na 0.67 Ni 0.33 Mn 0.67 O 2 , providing a facile tactic to develop high performance cathode materials 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
·
电池技术
✓ 已验证
DOI
高影响因子
Colloid and Interface Science Communications
·
2019
·
IF 1.87
Gaoqi Wang,Ding Weng,Chaolang Chen,Lei Chen,Jiadao Wang
The aim of the study was to explore the synergistic effects of nanostructure size and surface treatment of TiO 2 coatings on its wettability and bacteria adhesion. The coatings were fabricated by TiO 2 particles with a diameter ranging from 25 nm to 300 nm. The surface wettability of coatings was tuned by chemical treatment. The anti-adhesion property of as-prepared coatings was evaluated with Streptococcus mutans in two types of solutions: phosphate buffer solution (PBS) and PBS with 1 wt% sucrose. The results show that particle size and surface treatment have significant influences on the wettability (with contact angles of 0–160°) and bacterial adhesion. The coating prepared by chemically modified 25 nm particles has a superhydrophobic property, and could inhibit bacterial adhesion in aqueous solutions with sucrose or not. The study also provides a facile, universal and low-cost process to fabricate anti-adhesion coating, which is applicable for diverse of substrates.
研究领域:
生物材料学
·
纳米医学
·
表面科学
·
微生物学
·
口腔生物学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2017
·
IF 3.012
Haojie Zhu,Ke Yang,Hua Lan,Shangshu Qian,Haoxiang Yu,Lei Yan,Nengbing Long,Miao Shui,Jie Shu
In this work, Na 2 Ti 3 O 7 is fabricated as lithium storage material via one-step solid state reaction. Worked as anode material , Na 2 Ti 3 O 7 delivers a stable electrochemical performance with good lithium storage capability. Structural analyses show that Na 2 Ti 3 O 7 anode experiences slight volume change during electrochemical lithiation/delithiation process. Moreover, the reversibility of structural evolution is further demonstrated by in-situ X-ray diffraction technique . All these evidences prove the cycling stability of Na 2 Ti 3 O 7 as lithium storage material. Besides, the kinetic properties of the Li + ion storage in Na 2 Ti 3 O 7 are systematically investigated. The observed results reveal that Na 2 Ti 3 O 7 delivers the lithium ions diffusion coefficient in the range of 10 − 14 –10 − 12 cm 2 s − 1 during the discharge process and 10 − 15 –10 − 12 cm 2 s − 1 during the recharge process. It suggests that Na 2 Ti 3 O 7 has good lithiation/delithiation kinetics in rechargeable batteries.
研究领域:
电化学
·
材料科学
·
能源存储
·
无机化学
·
固体化学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2021
·
IF 5.234
Siqi Xiang,Xingjian Du,Yihan Liang,Mengcheng Zhou,Xinfang Zhang
Full density TiC reinforced Cu matrix composites are fabricated by electropulsing-assisted flash sintering within 40 s. The addition of TiC significantly increases the hardness of the sintered sample. However, liquid Cu does not wet stoichiometric TiC, leading to a poor interface bonding strength between TiC and Cu, thus the tensile strength of the sintered sample is destroyed. By adding a small amount of Ti, the bonding strength of the interface between TiC and Cu can be effectively optimized, thereby the mechanical strength of the samples is improved, showing an increased hardness and tensile strength . Skillfully use the relationship between hardness and tensile strength curve to intuitively show the bonding strength of the micro interface from the macro characteristics. The reaction between dissolved Ti and stoichiometric TiC and the decomposition of stoichiometric TiC cause the formation of near-surface non-stoichiometric TiC x ( x < 1) with a marked metal-like electronic structure, which is the fundamental reason for the optimization of the interface bonding between TiC particles and Cu matrix. In the process of powder metallurgy , it is a promising strategy to enhance the composite materials by adjusting the stoichiometry of ceramic to form metal-like electronic structure and alter the bonding strength of ceramic/metal interface.
研究领域:
材料科学
·
粉末冶金
·
金属基复合材料
·
界面工程
·
固态加工
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2024
·Vol. 12
·期 32
·2401539
·
IF 8
Qianjin Wang,Zhilin Xiang,Peizhi Yang,Yingkai Liu,Qiuhong Tan
Metal halide perovskites recently have emerged as a promising candidate for photodetection due to their exceptional photoelectric performance. However, the high dark current in these materials has hindered their practical application to imaging. In this study, a novel halogen-mixed CsPbIBr 2 microwire photodetector that has a remarkable reduction of dark current by over 100-fold (compared to CsPbBr 3 ), along with a substantial increase in photocurrent, which yields a significantly improved on/off ratio of 6.56 × 10 4 , is developed. More importantly, the halogen-mixed perovskite photodetector exhibits enhanced photodetection performance, including a high responsivity of 133 A W −1 and a remarkable specific detectivity of 4.02 × 10 12 Jones even under ultraweak light conditions as low as 4.5 nW cm −2 . More specifically, high-resolution images are successfully obtained under ultraweak light conditions. The combined analysis of experimental results and first-principles calculation attribute the excellent performance of the CsPbIBr₂ microwire photodetector to a significant reduction in dark current by suppressing ion migration and increasing carrier effective mass, and a remarkable increase in photocurrent resulting from reduced bandgap and enhanced light absorption, as compared to CsPbBr 3 . This research represents a significant advancement in the development of high-performance 1D perovskite-based photodetectors, with promising implications for ultra-weak light imaging applications.
研究领域:
光电子学
·
材料科学
·
纳米器件
·
半导体物理
·
生物医学成像
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 19
·11715-11721
·
IF 4.036
Baokang Zou,Yipeng Zhan,Xiuli Xie,TongTong Zhang,Runkai Qiu,Fangming Zhu
Two salalen titanium(IV) complexes ((H-salalen)TiCl2 and (F-salalen)TiCl2) containing hydrogen and fluorine respectively on the phenolate ring close to the imine were synthesized for the copolymerization of ethylene with 1-octene to prepare poly(ethylene-co-1-octene) in the presence of methylaluminoxane (MAO). The (F-salalen)TiCl2/MAO showed higher catalytic activity and better copolymer characteristics such as a higher molecular weight, narrower molecular weight distribution, and higher 1-octene incorporation than (H-salalen)TiCl2/MAO, which revealed that the electron-withdrawing conjugated effect introduced by fluorine substituents led to improvements on catalytic performance and thermal stability. The influences of copolymerization conditions including temperature, Al/Ti molar ratios and comonomer feed ratios on the copolymerization behavior of (F-salalen)TiCl2/MAO and the copolymer microstructure were investigated in detail. Under the activation of MAO, the (F-salalen)TiCl2 could produce ultrahigh molecular weight poly(ethylene-co-1-octene) with 1-octene incorporation ratios in the range of 0.9–3.1 mol% and exhibit relatively high activity. It could be inferred that long ethylene sequences in the copolymer were segregated by the isolated 1-octene units based on the 13C NMR characterization of the copolymer. Moreover, the thermal properties and crystallization of copolymers were determined by DSC and XRD and correlated to the ethylene sequence length distribution. The reactivity ratios calculated by the triad distribution in 13C NMR revealed the random comonomer distribution in the copolymer chain.
研究领域:
高分子化学
·
配位聚合
·
催化化学
·
材料科学
·
高分子物理
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·Vol. 10
·期 6
·108837
·
IF 7.968
Yumei Jian,Ye Meng,Jie Li,Hongguo Wu,Shunmugavel Saravanamurugan,Hu Li
Photocatalytic reductive conversion of bio-derivatives to biofuels and fine chemicals is an eco-friendly and energy-saving way for biomass valorization. Herein, we developed a new and high-performance protocol for control of activity/selectivity in photocatalytic reductive upgrading of biomass to biofuels at room temperature via engineering oxygen vacancy (Ov) and manipulating the exposed crystal surfaces of the TiO 2 -based catalysts, such as efficient cascade photocatalytic hydrogenation-cyclization of ethyl levulinate to γ-valerolactone in water (up to 96% yield, TOF: 112.1 h −1 ), and the selective conversion of 5-methylfurfural to 5-methylfurfuryl alcohol (90% yield) or long carbon-chain coupling products (86% yield) in methanol, respectively. The {101} crystal plane is prone to produce more Ov in situ than the {001} and {110} crystal planes. The formation of Ov was not only beneficial to the adsorption and activation of the bio-based carbonyls, but also could enhance the migration efficiency of the photo-generated carriers and effectively adjust the semiconductor band structure of the TiO 2 -based photocatalyst to promote the visible-light absorption, thus enhancing the overall reductive conversion process, as elucidated by DFT calculations. Also, the charge distribution and adsorption intensity of different exposed crystal surfaces of the photocatalyst were able to control the selectivity of the bioproducts . In addition, the optimal Ov-TiO 2− x {101} catalyst had excellent reusability and could be reused at least five times with no obvious decrease in photocatalytic performance. The strategy of selectivity control via engineering the catalyst exposed crystal surfaces and loaded Ov provides an opportunity for multi-catalytic biomass conversion to biofuels.
研究领域:
催化化学
·
材料科学
·
能源化学
·
环境科学
·
绿色化学
·
表面科学
·
光催化
✓ 已验证
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 36
·16907-16918
·
IF 6.97
Hong Lin,Jian Mao,Minchao Qin,Zhilong Song,Wanjian Yin,Xinhui Lu,Wallace C. H. Choy
While red is one of the primary colors for display applications, the investigation of visible red emitting perovskites, particularly 2D perovskites, is relatively limited. In this work, we demonstrate a single-phase Ruddlesden–Popper quasi-2D (C3H7NH3)2CsPb2I7 perovskite for red color LEDs. Through increasing the annealing temperature of (C3H7NH3)2CsPb2I7 perovskite thin films, we have successfully achieved tunable emission wavelengths from 654 to 691 nm. Equally important, for all the quasi-2D perovskite LEDs, once the annealing temperature is fixed, the emission spectrum is independent of bias voltages, which is very important for their use in lighting and displays. With the analysis of the crystallinity, morphology, and thermodynamic stability of the quasi-2D perovskite, we find that the obtained (C3H7NH3)2CsPb2I7 perovskite is a single-phase quasi-2D perovskite with only n = 2 phase. Besides, we found that the red shifting of emission wavelength is caused by the increase of perovskite crystal size while increasing the annealing temperature. Our results also show that the temperature-induced color tunability can be applied to a series of quasi-2D perovskites with different alkylammonium cations. Importantly, we find that short alkylammonium spacers offer better electrical properties for efficient current transport and high performance in LED applications. This work contributes to controlling the optoelectronic properties of quasi-2D perovskites via controlling their crystal growth as well as paves the way to realize practical lighting and display applications of perovskite LEDs.
研究领域:
材料科学
·
光电功能材料
·
半导体器件
·
纳米结构材料
·
固态照明
✓ 已验证
DOI
高影响因子
Small
·
2017
·Vol. 13
·期 25
·1700364
·
IF 8.643
Xuhai Liu,Dejian Yu,Fei Cao,Xiaoming Li,Jianping Ji,Jun Chen,Xiufeng Song,Haibo Zeng
All-inorganic photodetectors based on scattered CsPbBr 3 nanoplatelets with lateral dimension as large as 10 µm are fabricated, and the CsPbBr 3 nanoplatelets are solution processed governed by a newly developed ion-exchange soldering mechanism. Under illumination of a 442 nm laser, the photoresponsivity of photodetectors based on these scattered CsPbBr 3 nanoplatelets is as high as 34 A W −1 , which is the largest value reported from all-inorganic perovskite photodetectors with an external driven voltage as small as 1.5 V. Moreover, the rise and fall times are 0.6 and 0.9 ms, respectively, which are comparable to most of the state-of-the-art all-inorganic perovskite-based photodetectors. All the material synthesis and device characterization are conducted at room temperature in ambient air. This work demonstrates that the solution-processed large CsPbBr 3 nanoplatelets are attractive candidates to be applied in low-voltage, low-cost, ultra highly integrated optoelectronic devices.
研究领域:
材料科学
·
光电子学
·
纳米科技
·
半导体器件
·
凝聚态物理
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Jian Zhi,Houlei Cui,Angran Chen,Yian Xie,Fuqiang Huang
Dye-sensitized solar cells (DSSCs) on flexible plastic substrates usually suffer from a slower electron diffusion rate and insufficient surface area due to no sintering process . Therefore, the conversion efficiency (ƞ) of such flexible DSSCs is normally below 6%. Here, the highly flexible DSSCs with enhanced performance are fabricated at room temperature, employing 3D graphene decorated nanocrystalline TiO 2 films (3DGT) as anode on plastic substrates. Owing to the enhanced charge transportation and increased surface area from 3D conductive graphene skeleton, the 13 μm-thick 3DGT-0.85 (0.85 wt% 3D graphene plus TiO 2 nanoparticles) anode achieves a power conversion efficiency of 6.41%, which is 56% higher than pristine TiO 2 based anode. This efficiency is among the highest values for the previously reported TiO 2 photoanodes on plastic substrates.
研究领域:
材料科学
·
纳米科技
·
能源化学
·
光电转换
·
柔性电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yuxing Sun,Lei Zhao,Juan Yang,Xiang Wang,Huanjun Peng,Jingdong Peng
Light absorption range, recycling stability and charge transfer efficiency are key to the performance of photocatalytic material. Based on these targets, a Al doped TiO 2 catalyst was synthesized by the evaporation-induced process, after processed by NaBH 4 reduction, the black TiO 2 doped with Al was finally prepared. Uv-vis DRS, EPR and XPS analyses confirm the expanded light absorption window (300 nm - 1000 nm) and the introduction of abundant oxygen vacancy after the reduction process. The final product BTiO 2 /Al-0.5 has a degradation rate of about 84 % over the tetracycline hydrochloride within 60 minutes, the reaction rate constant (k) is 10.6 times higher than the unreduced sample. The dramatic change of photocatalytic ability can be assigned to the broadened visible light absorption , increased charge separation efficiency, narrowed band gap and defect-enriched oxygen vacancy . This work offers insights into the fabrication of TiO 2 catalyst and the introduction of oxygen defect.
研究领域:
材料科学
·
光催化
·
环境功能材料
·
纳米材料
·
表面化学
·
半导体催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）