Journal of Materiomics
·
2023
·
IF 9.4
Xinbo Liu,Youbing Li,Haoming Ding,Lu Chen,Shiyu Du,Zhifang Chai,Qing Huang
MAX phases and its derived two-dimensional MXenes have attracted considerable interest because of their rich structural chemistry and multifunctional applications. Lewis acid molten salt route provides an opportunity for structure design and performance manipulation of new MAX phases and MXenes, Although a series of new MAX phases and MXenes were successfully prepared via Lewis acid melt route in recent years, few work is explored on nitride MAX phases and MXenes. Herein, a new copper-based 413-type Ti 4 CuN 3 MAX phase was synthesized through isomorphous replacement reaction using Ti 4 AlN 3 MAX phase precursor in molten CuCl 2 . In addition, it was found that at high temperature Ti 4 N 3 Cl x MXene will transform into two-dimensional cubic TiN α nanosheets with improved structural stability.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2014
·
IF 0
Zheng Yang Li,Li Bo Wang,Guo Cai Zhong,Sai Sai Li,Ai Guo Zhou
Titanium tin carbide (Ti2SnC) is a member a MAX phases, which are ternary carbides or nitrides with layered structure. Ti powders are normally used as Ti source to synthesize Ti2SnC. In this paper, TiH2, a relative cheaper Ti source, was used to synthesize Ti2SnC. Ti2SnC was synthesized from TiH2/Sn/TiC or TiH2/Sn/graphite powders by a tube furnace at different temperatures under Ar atmosphere. From the analysis of X-ray diffraction results, the lowest temperature to synthesize Ti2SnC was 1000 °C. Ti2SnC content increased with temperature, and high purity Ti2SnC was fabricated at 1200 °C. From scanning electron microscopy, as-synthesized Ti2SnC from TiH2/Sn/TiC was with plate-like structure. However, for Ti2SnC from graphite as carbon source, there was some stripe microstructure. Some large pores existed between the Ti2SnC particles. The existence of the pores make the mechanical properties of Ti2SnC block significantly reduced, its compressive strength was only 0.483 MPa or 0.35 MPa respectively for samples synthesized from TiC or graphite as carbon source. The low mechanical properties make the porous sample easy to be broken as powders.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Lianshi Qu,Zhihao Zhao,Zhenyuan Li,Rao Zhang
MXene is a novel two-dimensional nano material with exceptional performance, which can be applied in the fields of energy storage structural materials, optics, catalysis, and sensors etc. However, its synthesis is a challenge to date. From the perspective of environmental friendliness, the method of Lewis salt etching can effectively avoid the use of dangerous reagents and has been seen as a pollution-free economic approach. In this article ZnCl 2 molten salt was chosen as corrosive agent to etch Ti 3 AlC 2 MAX phase and investigated the synthesis mechanism of Ti 3 C 2 Cl x MXene. The influence of main process factor, like raw materials, sintering temperature , and holding time on synthesis product were studied and discussed. The synthesis route was investigated by XRD and thermal analysis. SEM and TEM technology was used to analyze the microstructure and lattice of synthesis product. The results showed that the optimal process conditions: the molar ratio of raw materials was 1:6 (Ti 3 AlC 2 : ZnCl 2 ), the synthesis temperature and holding time were 600～700 °C and 4 h, respectively. Ti 3 C 2 Cl x MXene material prepared by this method has a complete layered structure and uniform composition, and its synthesis mechanism can be concluded to two steps: the first step was the reaction between Ti 3 AlC 2 MAX phase and ZnCl 2 to generate Ti 3 ZnC 2 MAX phase; In the second step, the Ti 3 ZnC 2 MAX phase reacted with the remaining ZnCl 2 to generate Ti 3 C 2 Cl x MXene material.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 16
·1-8
·
IF 2.8
Tang Jingwen,Tang Haifeng,Tian Zhihua,Wu Fushuo,Zhang Peigen,Sun ZhengMing
Ti 2 InB 2 , a typical member of MAB phases (a family of layered transition metal borides), has gained wide attention due to its excellent properties. However, in this work, Ti 2 InB 2 is found to share a similar A-site metal whisker growth phenomenon with MAX phases (a family of layered carbides/nitrides), which casts doubt on its reliability, and therefore would hinder its applications in advanced technologies. Specifically, the weaker bond between Ti and In atoms in Ti 2 InB 2 leads to the exfoliation of In atomic layers under mechanical damage. It is proposed that the In atoms released by the mechanochemically decomposed Ti 2 InB 2 have high chemical potentials and are inclined to crystallize, which is responsible for the In whisker growth. Furthermore, it is observed that the decomposition degree of Ti 2 InB 2 affects the whisker growth propensity and morphology. Understanding the In whisker growth mechanism is meaningful to ensure the reliability as Ti 2 InB 2 is finding technological applications.
研究领域:
材料科学
·
力学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 15
·9593-9601
·
IF 12.732
Yan Zhao,Meng Zhang,Hong Yan,Yu Feng,Xinyu Zhang,Ruijie Guo
Since the original discovery, MXene can be synthesized by wet-chemical etching from the MAX phase. To avoid the shortcomings of the previous etchant, NaHF2 aqueous solution was used for the selective removal of Al from Ti3AlC2, while intercalating Na+ between layers. The d-spacing of the resulting accordion-like Ti3C2Tx is up to 12.35 Å; the by-product Na3AlF6 can be removed by H2SO4, and the product yield can reach about 85%. After a short time of centrifugation and sonication, few-layer (10–20 layers) Ti3C2Tx sheets in a large lateral size (3–4 μm) can be prepared, with high conductivity up to 2.3 × 105 S m−1. Ti3C2Tx can be stably dispersed in water and organic solvents for at least 96 h, and has excellent anti-thermal-oxidation ability. As the anode for sodium ion batteries, the Ti3C2Tx electrode delivers a high reversible capacity of 70 mA h g−1 after 900 cycles at a current density of 1 A g−1 with an extremely low-capacity decay rate. From 900 to 1000 cycles, the capacity can even be increased to 130 mA h g−1, and the Coulomb efficiency is close to 100%, showing that MXene can provide a stable structure for the Na+ cycle.
研究领域:
材料科学
·
电化学
·
储能技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Wenjie Zhu,Yuwei Ren,Minghang Li,Yichun Bi,Ce Zheng,Xiaoqiang Li
Ti 3 SiC 2 MAX phase with a purity of up to 98 vol%, comparable to the purity of commercial Ti 3 SiC 2 prepared by Hot Pressing (HP), was synthesized by Reactive Melt Infiltration (RMI) in this work, overcoming the inherent shortcoming of RMI products' poor purity. Compared with HP Ti 3 SiC 2 , the lower preparation temperature and pressure-free fabrication of high-purity RMI Ti 3 SiC 2 make it promising for applications in the Ceramic Matrix Composites (CMCs), especially for complex shaped CMCs parts. This work systematically studied the generation mechanism of Ti 3 SiC 2 with the help of κ-Al 2 O 3 during the RMI process, which enables the successful production of high-purity Ti 3 SiC 2 . The toughening mechanism of Ti 3 SiC 2 in Ti 3 SiC 2 composites was also characterized and analyzed. This work attempts to provide a new idea for introducing high-purity ceramic phase into CMCs by RMI process.
研究领域:
材料科学
·
陶瓷材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Sheng Pang,Zhenqian Zhang,Liangwei Cong,Youpeng Xu,Guoyu Qian,Dong Wang,Laishi Li,Yusheng Wu,Zhi Wang
The conventional method for synthesizing Ti 2 SC depends on the reaction between TiS and TiC, which requires the utilization of costly Ti, TiC, or TiS 2 powders. Utilizing TiO 2 as the raw material for the synthesis of Ti 2 SC enables the cost-effective preparation of this compound. However, the optimization of the TiO 2 /C/X n S m (sulfides) system is of utmost importance when aiming to synthesize Ti 2 SC through carbothermal-sulfurization of TiO 2 , as the formation temperature of TiS and TiC greatly depends on the X n S m . In this study, the identification of the thermodynamically dominant region for the formation of TiS and TiC in the TiO 2 /C/X n S m systems was conducted by utilizing various sulfides (63 types). Considering factors such as the challenges associated with removing by-products, accessibility, and toxicity, FeS 2 was ultimately chosen as a highly promising candidate. Thanks to the low melting point of FeS 2 , Ti 3 O 5 , the preliminary carbothermal reduction product of TiO 2 , has achieved rapid-deep deoxidation and phase reconstruction processes in the molten phase. Meanwhile, unlike the conventional solid-solid sintering reaction , which often results in residual reactants that are challenging to eliminate. This novel one-step phase transformation process that occurs in the molten phase exhibits minimal impurity phases, apart from the by-product Fe. Ti 2 SC with a purity greater than 99 wt% was obtained when the TiO 2 /C/FeS 2 was pickled to remove Fe after sintering at 1600 °C for 5 min. This work will provide the theoretical basis and a new path for the low-cost preparation of sulfur-containing MAX phases.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Yina Du,Ji-Xuan Liu,Yifeng Gu,Xin-Gang Wang,Fangfang Xu,Guo-Jun Zhang
Textured and untextured M n+1 AX n compounds, Ti 2 AlC and Ti 3 AlC 2 , namely MAX phases have been synthesized and examined with respect to their corrosion resistance in static supercritical water at 500 °C. The textured ceramics were obtained by hot forging process at high temperatures. Both X-ray diffraction and SEM analysis revealed well alignment of c -plane of MAX phases parallel to the hot-forging surface. Better corrosion resistance on the surface perpendicular to the hot-forged direction was verified by SEM. On the other hand, the side surfaces of the samples showed thick oxidation layers and abundant cracks. The (00 l ) faces consist of strongly bonded Ti 3 C 2 and Ti 2 C layers in Ti 3 AlC 2 and Ti 2 AlC, respectively, hence exhibit higher resistance to water corrosion. On the contrary, the side surfaces where most of weakly bonded interlayers of these hexagonal phases were exposed tend to be easily corroded especially through Al-layers. The corrosion process involved a phase transition of oxidized product, i.e. TiO 2 from anatase to rutile phase, which gave rise to the formation of cracks due to accompanied volume changes.
研究领域:
材料科学
·
腐蚀工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2022
·Vol. 18
·期 32
·2203471
·
IF 15.153
Minhao Sheng,Xiaoqing Bin,Yawei Yang,Yi Tang,Wenxiu Que
MAX phases are frequently dominated as precursors for the preparation of the star material MXene, but less eye-dazzling by their own potential applications. In this work, the electrocatalytic hydrogen evolution reaction (HER) activity of MAX phase is investigated. The MAX-derived electrocatalysts are prepared by a two-step in situ electrosynthesis process, an electrochemical etching step followed by an electrochemical deposition step. First, a Mo 2 TiAlC 2 MAX phase is electrochemically etched in 0.5 m H 2 SO 4 electrolyte. Just several hours, electrochemical dealloy etching of Mo 2 TiAlC 2 MAX powders by applying anode current can acquire a moderated HER performance, outperforming most of reported pure MXene. It is speculated that in situ superficially architecting endogenous MAX/amorphous carbide (MAC) improves its intrinsic catalytic activity. Subsequently, highly active metallic Pt nanoparticles immobilized on MAC (MAC@Pt) shows a transcendental overpotential of 40 mV versus RHE in 0.5 m H 2 SO 4 and 79 mV in 1.0 m KOH at the current density of 10 mA cm −2 without iR correction. Ultrahigh mass activity of MAC@Pt (1.5 A mg pt −1 ) at 100 mV overpotential is also achieved, 29-folds than those of commercial PtC catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Advanced Ceramics
·
2022
·Vol. 11
·期 9
·1491-1497
·
IF 11.534
Liu Yi,Wang Chuangye,Luo Wei,Bai Liang,Xu Yang,Hao Xiaodong,Zhu Jianfeng,Guo Shouwu
The microstructure and morphology of Ti 3 AlC 2 powders not only affect the preparation of Ti 3 C 2 MXene but also have a great influence on their potential applications, such as microwave absorbers, alloy additives, or catalytic supports. However, the synthesis of Ti 3 AlC 2 powders with desired microstructure and morphology remains a challenge. Herein, hollow Ti 3 AlC 2 microrods were prepared for the first time in NaCl/KCl molten salts by using titanium, aluminum, and short carbon fibers as starting materials. It was found that the short carbon fibers not only performed as carbon source but also acted as sacrificial template. Furthermore, it was revealed that TiC and Ti 2 AlC were initially formed on the surface of carbon fibers. The subsequent reactions between the outer Ti, Al and the inner carbon were dominated by the Kirkendall effect which gave rise to the formation of a hollow structure. Based on this mechanism, hollow Ti 3 AlC 2 microspheres and a series of hollow TiC, Ti 2 AlC, and V 2 AlC powders were also successfully fabricated. This work provides a facile route to synthesize hollow MAX phases and may give enlightenment on preparing other hollow carbide powders via the Kirkendall effect in the molten salts.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·Vol. 107
·期 10
·6911-6920
·
IF 3.5
Ruixue Bai,Mian Li,Lingyan Feng,Qing Huang
The family of MAX phases and their two-dimensional derivative MXenes attract significant attention due to their unparalleled properties. Synthesis of MAX phases and MXene from biomass sources is important to expand their biology-related applications, while it remains a challenge. The present work explores the possibility to synthesize MAX phases and subsequently derive MXenes by using biomass precursor. Ti 3 AlC 2 MAX phase was synthesized by using glucose as the carbon source in molten salt. The conversion behavior from glucose to Ti 3 AlC 2 was investigated, and the conversion rate of carbon from glucose reached to 70.4% by optimizing the reaction conditions. The as-obtained Ti 3 AlC 2 can be derived into Ti 3 C 2 T x MXene and MXene quantum dots by common chemical treatments, which provides possibility for biomass-derived nanolaminates applying in biological applications such as biological catalysis, bioinstrumentation, and biological tracking.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Ke Chen,Youhu Chen,Jianning Zhang,Yujie Song,Xiaobing Zhou,Mian Li,Xiaomeng Fan,Jie Zhou,Qing Huang
Medium- and high-entropy alloys or ceramics for tuning the physicochemical properties of materials by the combination of multiple principal elements have received much interest. Herein, a medium-entropy (Ti, Zr, Hf) 2 SC phase was synthesized attributing to the structural and chemical diversity of MAX phases. The crystal structure of (Ti, Zr, Hf) 2 SC was determined by the Rietveld refinement of XRD , SEM, and atom-resolved TEM along with EDS elemental analysis . Phase evolution of X-ray diffraction patterns and TG/DSC curves were employed to reveal the synthesis mechanism of (Ti, Zr, Hf) 2 SC from 2TiC–Zr–ZrC-2HfH 2 -3.2FeS reactant system. The Vicker's hardness and the electrical resistivity of (Ti, Zr, Hf) 2 SC were found higher than those of Ti 2 SC, but the thermal conductivity of (Ti, Zr, Hf) 2 SC was lower.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）