Nanoscale
·
2013
·Vol. 5
·期 24
·12150-12155
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IF 6.233
Shunxing Li,Jie Chen,Fengying Zheng,Yancai Li,Fuying Huang
A novel double-shell TiO2 hollow sphere with an inner anatase shell and an outer rutile shell was synthesized by a simple sol–gel method and silica protected calcination process. The structure and formation mechanism was proposed based on characterization using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The double-shell spheres have a uniform diameter of 360 nm and a typical yolk–shell structure. Moreover, the double-shell TiO2 hollow spheres possess a large specific surface area (169 m2 g−1). Due to the high surface area, multiple light reflection and beneficial electron conduction between the inner anatase and outer rutile shell of this special structure, the as-prepared double-shell TiO2 catalysts show remarkably enhanced photoactivity compared to the commercial P25 catalyst. In particular, rhodamine B molecules can be completely decomposed in the presence of the double-shell spheres after 60 minutes of irradiation with UV light. In addition, the high activity is retained after five cycles, indicating the stability and reusability of the double-shell catalyst.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Light-Science & Applications
·
2024
·Vol. 13
·期 1
·1-11
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IF 20.6
Liu Guangyou,Wu Xinzao,Xiong Feng,Yang Jinglan,Liu Yunhe,Liu Jie,Li Zhuohang,Qin Zong,Deng Shaozhi,Yang Bo-Ru
Traditional optical anti-counterfeiting (AC) is achieved by static printed images, which makes them susceptible to lower levels of security and easier replication. Therefore, it is essential to develop AC device with dynamic modulation for higher security. Electrophoretic display (EPD) has the advantages of low power consumption, high ambient contrast ratio, and capability of showing dynamic images which is suitable for dynamic AC applications. Herein, we prepared a dynamical AC device based on a fluorescent EPD, and achieving the image switch between black, white, and green fluorescence states under the dual-mode driving (electronic field and UV light). We loaded perovskite quantum dots (CsPbBr 3 ) onto the TiO 2 particles and further prepared fluorescent electrophoretic particles TiO 2 /CsPbBr 3 -3-PLMA (TiO/CPB-3) by grafting and polymerizing method. In addition, we fabricated the AC devices based on the fluorescent EPD, which exhibits the multifunctional AC, where the fluorescent EPD has a fast response time of 350 ms, a high contrast ratio of 17, and bright green fluorescence. This prototype demonstrates a new way for future dynamic AC and identification.
研究领域:
材料科学
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光学工程
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显示技术
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Wenqing Zhang,Hu Wang,Zhilong Chen,Pengxiang Wang,Xin Liu,Hao Dong,Jiaoling Zhao,Yun Cui,Yuchuan Shao
High-energy radiation detectors with a good imaging resolution, fast response, and high sensitivity are desired to operate at a high electric field. However, strong ion migration triggered by electrochemical reactions at the interface between a high-potential electrode and an organic–inorganic hybrid perovskite limits the stability of radiation detectors under a high electric field. Herein, we demonstrate that such ion migration could be effectively suppressed in devices with a Ti cathode, even at a high electric field of 50 V mm–1, through time-of-flight secondary-ion mass spectrometry. X-ray photoelectron spectroscopy illustrates that Ti–N bonds formed at the interface of MAPbBr3 perovskite single crystals/Ti electrode effectively inhibit the electrochemical reaction in organic–inorganic hybrid perovskite devices and ultimately improve the operating stability under a high electric field. The device with a Ti electrode reaches a high sensitivity of 96 ± 1 mC Gyair–1 cm–2 and a low detection limit of 2.8 ± 0.3 nGy s–1 under hard X-ray energy.
研究领域:
材料科学
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辐射探测技术
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DOI
PubMed
高影响因子
Processes
·
2024
·Vol. 12
·期 1
·102
·
IF 2.8
Tingting Lv,Fang Tian,Tu Hu
Titanium carbide has attracted widespread attention due to its excellent properties. This study investigates the process of carbon thermally reducing TiO2to prepare TiC through a combination of thermodynamic analysis and experiments. The effects of temperature, TiO2/C molar ratio, and time on the phase transformation and morphology evolution of the products are investigated. The synthesis of titanium carbide involves the main reduction path of TiO2–Magnéli–Ti3O5–Ti2O3–TiCxO1−x. With the increase in reaction temperature and TiC content, the microstructure transitions from a smooth disc-like structure to a loose and porous layered structure, while the particle size decreases significantly. The carburisation rate of the reduced product is more affected by temperature, according to chemical analysis. The carburisation rate increased from 18.37% to 36.09% for 2 h–10 h of holding time at 1400 °C, and from 51.43% to 77.57% for 2 h–10 h of holding time at 1500 °C. The quantification of the carburisation rate provides a valuable reference for the preparation of titanium carbide by TiO2.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 6
·1828
·
IF 4.927
Yingjie Su,Jianqiang Xue,Anmin Liu,Tingli Ma,Liguo Gao
Controlling the crystallographic orientations of 2D perovskite is regarded as an effective way to improve the efficiency of PSCs based on 2D perovskite. In this paper, five different assistant solvents were selected to unveil the effect of solvents on crystallization and morphology of 2D perovskite in a solvent-assisted method. Results demonstrated that the effect of Lewis basicity on the crystallization process was the most important factor for preparing 2D perovskite. The stability of the intermediate, reacted between the solvent and the Pb2+, determined the quality of 2D film. The stronger the Lewis basicity was, the more obvious the accurate control effect on the top-down crystallization process of 2D perovskite would be. This could enhance the crystallographic orientation of 2D perovskite. The effect of Lewis basicity played a more important role than other properties of the solvent, such as boiling point and polarity.Keywords:2D perovskite;perovskite solar cells;crystallization orientation;solvent
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2015
·
IF 7.435
Yanfeng Cao,Xiaoting Li,Zhenfeng Bian,Addis Fuhr,Dieqing Zhang,Jian Zhu
A facile solvothermal approach was used to prepare brookite-type TiO 2 nanocrystals with different phase content and structure, accomplished by adjusting the ratio of TiCl 4 to t -BuOH. The obtained biphasic brookite/rutile TiO 2 nanocrystals showed a high brookite weight content (72%). The photocatalytic degradation of phenol under UV-irradiation was used to determine the synergetic effect from the combination of different phases ( e.g. , brookite, anatase, and rutile). The biphasic NST-4 composed of brookite and rutile exhibited the highest degradation rates, with rate constants three times higher than commercial Degussa P-25. Detailed analysis found that, besides phase composition and content, the semi-embedded structure was essential to obtain a superior activity of biphasic TiO 2 samples.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
JOM
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2021
·Vol. 74
·期 1
·213-221
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IF 2.474
Deng Pan,Li Liang,Jia Yaoqiang,Liu Dachun,Jiang Wenlong,Kong Lingxin
Aluminum chloride (AlCl 3 ) is an effective chlorinating agent and catalyst for the chlorination of low-grade titanium slag to produce titanium tetrachloride in molten salts. In this paper, the chlorination behavior of low-grade titanium slag by anhydrous AlCl 3 in AlCl 3 -NaCl molten salt was investigated. Thermodynamic analysis revealed that aluminum chloride can be an effective agent for low-grade titanium slag, and that the addition of NaCl can form a compound molten salt together with AlCl 3 to prevent the evaporation of AlCl 3 .chlorination experiments were conducted on low-grade titanium slag in AlCl 3 -NaCl molten salt to investigate the effects of temperature and the amounts of aluminum chloride and sodium chloride added. Under optimized experimental conditions, the selective separation of titanium from the titanium slag was effectively achieved, and the extraction rate of titanium reached 79.6%. Other impurity elements in the form of oxides or chlorides remained in the residue. Finally, a reaction mechanism for the extraction of titanium from low-grade titanium slag in AlCl 3 -NaCl molten salt has been proposed.
研究领域:
冶金学
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材料科学
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DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 10
·期 2
·891-901
·
IF 12.732
Fan Yang,Yidong Hu,Qiaodan Hu,Sebastian Steiner,Till Frömling,Linhao Li,Patrick Wu,Emilio Pradal-Velázquez,Derek C. Sinclair
Bulk conductivity (σb) values of nominally stoichiometric Na0.5Bi0.5TiO3 (NBT) prepared by solid-state reaction collated from literature show random variation between 10−6 to 10−3 S cm−1 (at 600 °C). This makes it challenging to obtain reliable and reproducible performances of NBT-based devices, especially as the underlying reason(s) for this variance are not fully understood. Here we report the dramatic impact of the TiO2 reagent, in particular, the polymorphic form of TiO2 on the electrical conductivity and conduction mechanism of NBT. Based on our solid-state processing route, NBT ceramics prepared by rutile TiO2 are ionically conductive, and those prepared by anatase TiO2 are insulating. The dramatic difference in electrical properties of NBT prepared using rutile and anatase TiO2 is related to the NBT formation process: the intermediate phase Bi12TiO20 is more stable during formation of NBT in the case of anatase TiO2, which reduces the volatility of Bi2O3 during solid-state reaction. These results give plausible explanations for the large variation of σb reported in the literature and highlight the importance of selecting an appropriate TiO2 reagent when targeting controllable σb in NBT-based ceramics. For ion-conducting applications (such as in intermediate-temperature solid oxide fuel cells, IT-SOFCs), rutile TiO2 should be used, and for dielectric applications (such as in multilayer ceramic capacitors, MLCC) anatase TiO2 should be used.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
IONICS
·
2023
·Vol. 29
·期 4
·1479-1486
·
IF 2.8
Liu Yang,Chen Han,Lou Xiaoming,Wen Xiaoyu,Yin Zhenguo,Xiang Kaixiong
Rechargeable aqueous ammonium-ion batteries (AAIBs) have attracted more and more attention in energy storage devices because of great safety and cost-effectiveness, as well as excellent rate capability. Recently, it is the main exploration focus for the further improvement of AAIBs to develop suitable electrode materials. Herein, titanic acid and TiO 2 were simply synthesized by the facile co-precipitation approach. Titanic acid showed higher capacity of 104.5 mAh g −1 at the 0.1 A g −1 current density, and higher cyclability with the 91.2% capacity retention cycled 1000 cycles at 1 A g −1 . Titanic acid is promising as aqueous ammonium-ion batteries with great stability and capacity.
研究领域:
材料科学
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电化学
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DOI
高影响因子
SOLID STATE SCIENCES
·
2023
·
IF 3.5
Guang Yang,Hengwei Yan,Zhanwei Liu,Wenhui Ma,Shenghui Guo,Yonghui Yang
In this study, aluminothermic reduction and molten salt electrolysis were combined to prepare titanium powder. In this combined method, titanium dioxide was first deoxidized to produce titanium–aluminum alloy through an aluminothermic reduction reaction, and then the titanium–aluminum alloy was separated through chloride molten salt electrolysis to generate titanium powder. The obtained titanium powder, titanium aluminum alloy and slag was analyzed using several techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. A mass ratio of 2:3 of titanium dioxide and aluminum was suitable for the production of titanium–aluminum alloys. A large amount of alumina generated through the aluminothermic reduction reaction was separated into slag phases using cryolite. Then, the phases were electrolyzed into aluminum and cryolite, which were reused as raw materials. The final titanium–aluminum alloy product was electrolyzed in a chloride molten salt system to separate titanium and aluminum and produce titanium powder. Therefore, the combination of thermal reduction and molten salt electrolysis is efficient and has great potential for producing high-purity titanium powder.
研究领域:
材料科学
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冶金工程
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DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2023
·
IF 4.5
Zhao-wang DONG,Xue-yi GUO,Yang XIA,Pei-dong LIU,Jin-xi QIAO,Zhong-chen LI,Han-ning LIU
Silicon in two types of upgraded titania slag (UGS) containing different components was removed using a low-temperature alkali solution and melt leaching. The effects of temperature, time, and NaOH solution concentration on desilication rate were investigated. Desilication in melt can lead to the loss of titanium in upgraded titania slag. After agitating at a speed of 600 r/min and 80 °C for 300 min, the silicon content in domestic slag decreased from 0.96 wt.% to 0.29 wt.%, and the leaching rate was 69.8% after leaching in 4 mol/L sodium hydroxide solution. Under the same conditions, the silicon content in imported slag decreased from 1.11 wt.% to 0.12 wt.%, and the desilication rate was up to 89.2%. The alloy powders obtained from the reduction of upgraded titania slag with magnesium were sintered to produce titanium alloy, and the alloy was characterized. It was determined that the Ti 5 Si 3 phase in the titanium alloy product was successfully eliminated. In addition, the two UGS materials and the chemical principle of desiliconization were analyzed using a thermodynamic software.
研究领域:
材料科学
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冶金工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Faxiang Lu,Xiumin Xu,Yang Cao,Xingfu Zhou
The electron transport layer (ETL) plays an important part in perovskite solar cell (PSC) devices. TiO 2 nanorod arrays (TiO 2 NAs) is widely used as ETL for perovskite solar cells because of its excellent energy level matching. Furthermore, TiO 2 NAs provide the directed 1-D electron transmission channel. In this work, rutile TiO 2 NAs synthesized by one-step hydrothermal method were used as the ETL of carbon-based perovskite solar cells to improve the performance. The interface between the ETL and perovskite was modified by barium acetate to reduce interface defects, non-radiative recombination and improve the electron transport rate. The perovskite film based on the Ba@TiO 2 NAs exhibited larger grains and fewer grain boundaries, which was of positive significance for improving the power conversion efficiency (PCE) of devices. At the same time, we replaced the precious metal electrode and unstable organic hole transport layer (HTL) with carbon electrode, which reduces the manufacturing cost and improves the stability of the device. Finally, all inorganic HTL-free carbon-based perovskite solar cells based on Ba@TiO 2 NAs showed a champion PCE of 10.74%, which is 14.74% higher than the control device.
研究领域:
材料科学
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能源科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）