NEW JOURNAL OF CHEMISTRY
·
2025
·
IF 2.5
Si Guo,Chao Deng,Gang Shi,Dawei Wang,Likui Wang
MXenes are emerging as highly promising materials for pseudocapacitive applications, offering exceptionally high specific capacitance. To date, over 30 distinct MXene compositions and nearly 20 solid solutions have been synthesized in the lab. However, research predominantly centers on Ti3C2Tx and a handful of other single-metal MXenes, with scant attention paid to solid-solution MXenes. Herein, a series of solid solution MAX phases (Nb1−yTiy)4AlC3 and corresponding (Nb1−yTiy)4C3Tx MXenes have been synthesized. The maximum proportion of Ti that can be incorporated into the M site has been examined. We found that the rate performance of MXenes improves with increasing Ti content. Especially, (Nb0.7Ti0.3)4C3Tx and (Nb0.6Ti0.4)4C3Tx retain 62.92% and 68.38% of their capacitances, when the scan rate is increased from 5 mV s−1 to 1000 mV s−1, respectively, compared to Nb4C3Tx's 13.88% retention. (Nb0.7Ti0.3)4C3Tx shows a specific capacitance of 311.06 F g−1 under a current density of 1 A g−1 and good cycling stability. This research demonstrates that the electrochemical characteristics of (Nb1−yTiy)4C3Tx solid solution MXenes can be manipulated by adjusting the ratio of transition metals.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2016
·
IF 3.997
Jianjun Sha,Jian Li,Shouhao Wang,Zhaofu Zhang,Yongchang Wang,Jixiang Dai
ZrC-based ceramic composites doped with 20 vol.% titanium (Ti) and 3 vol.% carbon nanotubes (CNTs) were prepared by hot pressing. The densification behavior, microstructural evolution and mechanical properties of the composites were studied. The results indicated that the sinterability of the composites was significantly improved, resulting in highly dense matrix (98.27%) at reduced sintering temperature (1600 °C). In addition to the main phase of (Zr, Ti)C, the composites also contained a certain amount of TiC, which was shown to be beneficial for the improvement of mechanical properties. As a result, the flexural strength of the composites was measured to be 415 MPa at room temperature and 647 MPa at 800 °C, respectively. Moreover, the composites showed a high fracture toughness of 5.27 MPa m 1/2 , which increased by 32% compared with the monolithic ZrC (4 MPa m 1/2 ). The improved fracture toughness was attributed to crack deflection, crack bridging and crack branching.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 30
·4471-4475
·
IF 1.9
L. F. Tian,D. S. Zou,Y. C. Dai,L. L. Wang,W. Gao
Quantification of chromium in V–Cr–Ti ternary alloys, used as candidate structural materials for fusion reactors, is essential in view of its significant effect on the properties of these vanadium-based alloys. Various methods have already been used for the determination of chromium in common alloys, but most of these methods are based on complicated and expensive instruments or suffer from the serious matrix interference of vanadium. In this study, a simple, rapid and accurate spectrophotometric method was developed for the determination of chromium in V–Cr–Ti alloys without any prior separation and chromogenic agent. The alloy samples were dissolved in diluted sulphuric acid and concentrated nitric acid, and chromium was oxidized with persulphate in the presence of Ag(I) ions as a catalyst. After alkalization of the solution with sodium hydrate, greenish-yellow coloured chromate (CrO42−) ions were formed in the alkaline solution and had a maximum absorption peak at 374 nm. Beer's law was obeyed in the range of 0.15–12.0 μg mL−1 Cr(VI) at 374 nm and the molar absorptivity was 4.8 × 103 L mol−1 cm−1. All the variables were studied in order to optimize the analytical conditions. Vanadium and titanium seriously interfered with the determination of Cr(VI) and their interference can be eliminated by addition of ammonium tartrate. The proposed method is simple, fast, accurate and of low cost, and has been satisfactorily used for the determination of chromium in V–Cr–Ti alloys. The results are in good agreement with data given by inductively coupled plasma optical emission spectrometry (ICP-OES) and the relative standard deviation is found to be lower than 0.4%.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 12
·2904
·
IF 3.1
Xin Yang,Kaihua Li,Jun Li,Zhuo Sheng,Ying Liu
In this work, the preparation of titanium sponge by magnesium thermal method is regarded as the liquid-phase sintering process of titanium, and powder-metallurgy sintering technology is utilized to simulate the aggregation–growth and densification behavior of titanium particles in a high-temperature liquid medium (the molten Mg-MgCl2system). It was found that compared with MgCl2, Mg has better high-temperature wettability and reduction effect, which promotes titanium particles to form a sponge titanium skeleton at lower temperature. The aggregation degree of titanium particles and the densification degree of a sponge titanium skeleton can be improved by increasing the temperature and the relative content of Mg in the melting medium. The kinetics study shows that with the increase in temperature, the porosity of the titanium particle aggregates and the sponge titanium skeleton decreases, and their density growth rate increases. With the extension of time, the aggregation degree of titanium particles and the densification degree of sponge titanium gradually increase. This work provides a theoretical reference for controlling the density of titanium sponge in industry.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jun Han,Junhui Shao,Xingchen He,Najun Li,Shuxian Wang,Dongyun Chen,Jianmei Lu
Constructing heterojunctions has been proved to effectively improve the carrier transfer capability for enhanced catalytic activity. Herein, Ti 3 C 2 /BaTiO 3 heterojunctions were fabricated through self-assembly driven by hydrogen bonding between piezoelectric barium titanate (BaTiO 3 ) stabilized by oleic acid molecules and titanium carbide (Ti 3 C 2 ) with surficial functional groups under continuous ultrasonic vibration. Owing to the formation of heterojunction, the separation of free charges can be promoted by the conductive Ti 3 C 2 . Additionally, the recombination of electrons and holes pairs in BaTiO 3 can be hindered by built-in piezoelectric field. Hence, the piezocatalytic activity of Ti 3 C 2 /BaTiO 3 was significantly enhanced by the accumulated piezoelectric effect, maintaining stability during the piezocatalytic degradation of bisphenol A and achieving rate constants that were 22.2 and 3.2 times higher than those of Ti 3 C 2 and BaTiO 3 , respectively. This work thus presents a novel strategy for designing high-activity heterojunction piezocatalysts through hydrogen bonding self-assembly.
研究领域:
材料科学
·
催化化学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 5
·1591-1597
·
IF 6.641
Deying Kong,Dali Cheng,Xuewen Wang,Kaiyuan Zhang,Huachun Wang,Kai Liu,Huanglong Li,Xing Sheng,Lan Yin
Metal halide based perovskite materials have attracted tremendous interest in optoelectronics. Although conventional lead (Pb) based organic/inorganic halide perovskites have been extensively studied and have realized highly efficient devices like solar cells and light emitting diodes, they are plagued with the toxicity of the Pb element, restraining their applications in environmentally and biologically friendly scenarios. Substitutes for Pb ions have been suggested, yet most of the Pb-free perovskites suffer from low stability and inferior efficiencies compared to their Pb based counterparts. In this work, we explore the synthesis of cesium titanium halide perovskites (Cs2TiX6, X = Cl, Br). At room-temperature, aqueous solution-based processes are developed to grow thermally stable, high quality Cs2Ti(BrxCl1−x)6 (0 < x < 1) crystals and films in large volume. Their structural, thermal and optical properties are systematically studied in experiments and compared with first principles calculations. The produced materials demonstrate a tunable, quasi-direct band gap from ∼1.7 eV to ∼2.5 eV and photoluminescence peaked from ∼535 nm to ∼670 nm. Furthermore, the materials are stable in an ambient environment up to ∼500 °C. These Pb-free perovskite materials will create opportunities for novel optical and electronic devices used in eco-friendly and bio-friendly environments.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2025
·
IF 4.7
Pan CHEN,Jia-yan LIU,Ji-hua ZHAI,Yao-hui YANG,Wei SUN
n-octylphosphonic acid (OPA) was introduced as a novel collector for ilmenite flotation and its effectiveness was compared with the conventional chelating collector, benzohydroxamic acid (BHA). Micro-flotation tests demonstrated that OPA was a highly effective and selective collector for separating ilmenite from titanaugite over acidic conditions (optimal pH around 3), which was also supported by adsorption amount measurements. X-ray photoelectron spectroscopy (XPS) tests indicated that the chemisorption of OPA onto ilmenite surface was much stronger than that of BHA. Solution chemistry diagram analyses indicated that OPA could dissociate well at pH 3.0 and mostly exist in anion form. DFT calculations further confirmed that OPA was much easier to adsorb onto ilmenite surface with shorter bond length and lower adsorption energy in comparison with BHA. Therefore, OPA maintained good collecting ability and selectivity for ilmenite flotation in the strongly acidic pulp, providing valuable insights into new collector design and development.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2018
·
IF 1.686
Zi-Chang Wu,Yi Lu,Yong Wang,Yuan-Zhou Li,Li He,Xiu Cheng,Wei Geng,Jie Ying,Gang-Gang Chang
A hierarchical structured TiO 2 @C photocatalyst has been fabricated by using P25 as model nano-photocatalyst and dictyophora indusiata as a natural hierarchical template, which showed significantly higher photocatalytic performance in comparison with P25 and M-TiO 2 @C. The enhanced catalytic properties can be mainly ascribed to the formation of titanium vacancy and promoted diffusion and transport of substrate molecule benefited from the hierarchical structure.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 7
·1-12
·
IF 2.8
Yin Lixiong,Guo Yao,Liu Changqing,Li Luyao,Fan Dejiang,Huang Jianfeng,Zhang Qinghua,Wang Tao,Chen Yufei
Carbon-based organic-inorganic perovskite solar cells (C-PSCs) are low-cost photovoltaic cells. However, the carrier recombination caused by interface defects and the mismatched interface energy level limits the further improvement of the efficiency of C-PSCs. In this work, SmCl 3 was introduced as a “double-sided” modifier to achieve interfacial modification. After modified, Cl − passivated the oxygen vacancy defects on the TiO 2 surface. Meanwhile, Sm 3+ was diffused into the perovskite interface in the form of a concentration gradient, which balanced the non-coordinated Pb 2+ and improved the energy level arrangement. Due to good interfacial contact, the reduced interfacial non-radiative recombination, and rapid charge extraction and transport, the optimized C-PSCs efficiency was increased from 11.03 to 13.4%. In addition, the unencapsulated champion PSC remained stable for long-term stability after the sustained attack for 800 h at room temperature of 20% RH. This work proposed a straightforward interface modification strategy to improve the efficiency of C-PSCs.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Xiaoqin Sun,Yongli Mi,Feng Jiao,Xiaoxiang Xu
Solar water splitting into H2 and O2 upon a particulate photocatalyst relies on significant advances in material engineering where a number of important properties such as optical absorption, charge transportation, defect level, etc. can be manipulated. In this work, we have gained control over these properties for the wide band gap semiconductor Sr2TiO4 and successfully actualized water splitting under visible light illumination. This has been realized by codoping La/N into the laminated perovskite structure of Sr2TiO4. Strong visible light absorption as far as 650 nm can be tailored by varying the La/N content in Sr2–xLaxTiO4–yNy (0 ≤ x ≤ 0.5). Optimal photocatalytic H2 and O2 production has been achieved at x = 0.2, 0.3 and outweighs that of a number of typical perovskite oxynitrides. These activities are a function of several important parameters for photogenerated charges (e.g., concentration, mobility, and lifetime) which are all linked to La/N codoping levels. More strikingly, overall water splitting has been achieved at x = 0.2 with Rh/Cr2O3 as a cocatalyst. Defects such as Ti3+ species play a negative role in the photocatalytic activity, as they strongly promote charge recombination and shorten the electron lifetime. Theoretical calculations reveal the crucial role of N in uplifting the valence band maximum of Sr2TiO4 by hybridization with O 2p orbitals. La, therefore, balances the charge discrepancies induced during N/O replacements which would otherwise be unfeasible for substantial doping. Our calculations also suggest that Sr2TiO4 has a 2D charge transportation character which is extremely useful for charge separations.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Handong Jiao,Jianxun Song
Owing to the enhanced selective depolarization effect of the liquid Cu, Ti has been successfully collected from mixed oxide ores or slags by using advanced molten oxide electrolysis (MOE) configuring with a liquid Cu cathode. However, the products prepared via above process are Cu-Ti alloys. Additional process is needed for the separation of Ti from those alloys. To achieve this goal, here, we selected a simple electrochemical approach to separate Ti from the Cu-Ti alloys in molten salt. Compared to the pure Cu electrode, the Cu-Ti alloys with different Ti contents show more negative electro-oxidation potential, which, in principle, indicates that Ti could be electrochemically extracted from the Cu-Ti alloys. Furthermore, the results of constant current electrolysis show that the effective separation of Ti is affected by the anodic current density and the Ti content in the Cu-Ti alloys. Specifically, the anodic current density, enabling the effective separation of Ti, increases with the increase of the Ti content in the Cu-Ti alloys. We have fitted a relationship equation between the anodic current density and the Ti content, which will be helpful for guiding separation of Ti from the Cu-Ti alloys. These findings confirm the feasibility of the molten salt electrolysis for the separation of Ti, and also make the Ti extraction based on the advanced MOE a complete process.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 27
·2207915
·
IF 13.3
Jinchen Zhou,Daofu Wu,Changqing Tian,Zhiyu Liang,Hongmei Ran,Bo Gao,Zhongtao Luo,Qiang Huang,Xiaosheng Tang
Lead halide perovskite materials have great potential for photocatalytic reaction due to their low fabrication cost, unique optical absorption coefficient, and suitable band structures. However, the main problems are the toxicity and instability of the lead halide perovskite materials. Therefore, a facile synthetic method is used to prepare lead-free environmentally friendly Cs 2 TiX 6 (X = Cl, Cl 0.5 Br 0.5 , Br) perovskite materials. Their structural and optical characteristics are systematically investigated. The band gaps of the produced samples are illustrated to be from 1.87 to 2.73 eV. Moreover, these materials can keep high stability in harsh environments such as illumination and heating, and the Cs 2 Ti(Cl 0.5 Br 0.5 ) 6 microcrystals demonstrate the yields of 176 µmol g −1 for CO and 78.9 µmol g −1 for CH 4 after light irradiation for 3 h, which is of the first report of Ti-based perovskite photocatalysts. This finding demonstrates that the Ti-based perovskites will create opportunities for photocatalytic applications, which may offer a new idea to construct low-cost, eco-friendly, and bio-friendly photocatalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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