CHEMICAL PHYSICS LETTERS
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2020
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IF 2.029
Zijun Sun,Guisong Fang,Jinglin Li,Jiahuan Mo,Xiong He,Xu Wang,Zhiqiang Yu
Hematite (α-Fe 2 O 3 ) is one of the promising photoanode materials for photoelectrochemical (PEC) water splitting, but its poor bulk charge transfer has been challenging towards its practical application. Herein, we have synthesized the (Ti, Zr) co-doped hematite by a facile hydrothermal method. The cooperation of (Ti, Zr) co-doped hematite yields photocurrent density of 1.51 mA cm −2 at 1.23 V vs. RHE and IPCE of 17.3% at 400 nm. The structural and PEC analysis indicate that the considerably PEC performance improvement is contributed to the higher carrier density and enhanced charge transfer of the synergistic effect of Ti and Zr co-doping.
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高影响因子
RARE METALS
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2020
·Vol. 40
·期 7
·1940-1948
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IF 2.161
Li Jia-Xin,Chen Yu-Hong,Bai Zhang-Jun,Zhao Bao-Jun,Jiang Liang,Wu Lan-Er
Ta–W alloys have unique properties but their applications at high temperatures are restricted due to their poor oxidation resistances. The addition of Al and Ti decreases the oxidation rate of the alloy, as Al-contained protective oxide layer could be formed. In this study, ternary and quaternary Ta–W alloys containing Al and Ti were prepared by hot press sintering. The microstructures and oxidation behaviors of the alloys were studied at 1173 K. The results show that the oxidation kinetics of all alloys follows a parabolic law at short oxidation periods. After cyclic oxidation, the kinetics of quaternary alloys still obeys the parabolic law but that of ternary alloy has been changed into linear law kinetics after 8-h oxidation. For ternary alloy, an outer layer with dense and continuous alumina was formed during the initial stage, and phase transformation caused the oxides to peel off. By comparison, the quaternary alloys depicted continuously solid solution of the oxides layer. Overall, Al and Ti played key roles in oxidation degree and affected the oxidation kinetics of ternary and quaternary alloys.
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CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Wanjun Zhao,Hui Ren,Tao Yan,Yapeng Ou,Qingjie Jiao,Haiyang Wang,Dylan J. Kline,Michael R. Zachariah
This work explores the ignition mechanism of silicon (Si) based thermites, and it is supposed that the phase change of silica (SiO 2 ) coating on the Si core producing fractures may play a crucial role in the ignition of Si-based thermites. Several Si-based thermites were evaluated by the combustion test and calorimeter, and potassium perchlorate (KClO 4 ) is turned out to be a promising oxidizer given the high reactivity and considerable heat release. Titanium (Ti) nanoparticles with a lower onset oxidization temperature than Si were incorporated into Si/KClO 4 system via a facile sonicating method. The ignition temperature of Si/KClO 4 has reduced markedly by ~80–130 °C with significant increases of ~5-8x in pressurization rate and decreases by a factor of ~2–3 in burn time when adding 30–70% Ti by mole into the fuel. The combustion efficiency is improved dramatically from ~59% to ~73%. The enhanced combustion performance could be attributed to the lower ignition temperature of Ti/KClO 4 leading to the initiation reaction of the ternary composites, thus promoting energy release and the reactivity of the ternary system. This work not only investigates the ignition mechanism of Si-based thermites but also sets a stage for tuning the ignition and combustion of Si-based thermites via facile incorporation of Ti nanoparticles.
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Journal of Energy Chemistry
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2020
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IF 7.216
Xiao Liu,Peijie Fan,Liangping Xiao,Jian Weng,Qingchi Xu,Jun Xu
The generation of green hydrogen (H 2 ) energy is of great significance to solve worldwide energy and environmental issues. Reduced Ti based photocatalyst has recently attracted intensive attention due to its excellent photocatalytic activity, while the synthesis of reduced Ti based photocatalysts with high stability is still a great challenge. Here, we report a facile method for synthesis of reduced Ti metal organic frameworks (small amounts of Pt incorporated) encapsulated BP (BP/R-Ti-MOFs/Pt) hybrid nanomaterial with enhanced photocatalytic activity. The strong interaction between Ti and P reduces the valence state of the binding Ti 4+ on the BP surface, forming abundant reduced Ti 4+ within R-Ti-MOFs/BP. Such reduced Ti 4+ render R-Ti-MOFs/BP efficient charge transfer and excellent light absorption capability, thus promote the photocatalytic H 2 production efficiency. Furthermore, the Ti-P interaction stabilizes both reduced Ti 4+ and BP during the photocatalytic reaction, which greatly enhanced the stability of the obtained BP/R-Ti-MOFs/Pt photocatalyst.
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MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
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2019
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IF 4.081
Ni Xiong,Rui Bao,Jianhong Yi,Jingmei Tao,Yichun Liu,Dong Fang
Carbon Nanotubes (CNTs)/Cu-Ti composites with strong interfacial bonding were successfully prepared by Molecular Level Mixing (MLM) combined with Spark Plasma Sintering (SPS) method. The relationship between interface evolution and mechanical properties was carefully investigated by High Resolution Transmission Electron Microscopy (HRTEM). It was found that three typical transition interfaces (Ti 8 C 5 , Ti 8 C 5 +TiC, TiC) were formed between the CNTs and the Cu-Ti matrix when 0.3 wt% CNTs/Cu-Ti composite powder was sintered at 1073 K for 10min, 20min and 30min respectively. Strong interfacial bonding and well-preserved CNTs structure were simultaneously realized in the sample which was sintered at 1073 K for 10min. The interface evolution phenomenon of the Ti 8 C 5 to the TiC interface transition phase and a parallel orientation relationship ((219) Ti8C5 //(111) TiC ) were observed under a sintering time of 20 min at 1073 K. The 0.3 wt% CNTs/Cu-Ti composites sintered at 1073 K for 10 min exhibited yield strength of 368 MPa and tensile strength of 512 MPa, which were 59% and 51% higher than that of unreinforced Cu-Ti, 27% and 25% higher than that of 0.3 wt% CNTs/Cu composites without alloying. This study provides some new insights into the interfacial regulation of the CNTs/Cu composites with strong interfacial bonding and reinforcing effects.
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MATERIALS LETTERS
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2019
·
IF 3.019
Wanjun Zhao,Hui Ren,Yapeng Ou,Qingjie Jiao
The ignition temperature and combustion behavior are key parameters for the performance of energetic nanocomposites. This article aims to obtain nanocomposites with low ignition temperature and high reactivity by incorporating titanium nanoparticles (nTi) to aluminum nanoparticles (nAl)-based thermites. The ignition temperature, reactivity, and combustion efficiency of Al/xTi/oxidizer composites were investigated via temperature-jump (T-jump), combustion test, and calorimeter. The results reveal that the ignition temperature of Al/ x Ti/oxidizer composites shifted down ~90 °C, ~140 °C, and ~220 °C by adding 50 mol.% nTi (in the fuel) into nAl/KClO 4 , nAl/K 2 S 2 O 8 , and nAl/KIO 4 respectively. The reactivity of nAl/K 2 S 2 O 8 and nAl/KIO 4 also increased by 50% after adding 30% nTi. However, the combustion efficiency of nAl-based energetic composites reduced with the increasing contents of nTi. This study demonstrates that Al/ x Ti/K 2 S 2 O 8 and Al/ x Ti/KIO 4 nanocomposites with low ignition temperature, high reactivity, and moderate combustion efficiency are good candidates for energetic applications.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Pingping Gao,Zhiyong Xie,Xiaobo Wu,Chun Ouyang,Ting Lei,Piaopiao Yang,Chunbo Liu,Junbin Wang,Tao Ouyang,Qizhong Huang
A highly corrosion resistant and conductive carbon/PTFE/TiN composite coating on Ti bipolar plates is prepared by a two-step hydrothermal and impregnation process. The composite coating exhibits a full coverage with uniformly distributed PTFE and TiN particles when 0.1 mol/L of glucose is used as carbon source and 10 wt % PFTE + 3 g/L TiN suspension as impregnating solution. The as-prepared composite coating film shows 0.009 μA cm −2 of corrosion current density and 13 mΩ cm 2 of ICR in the simulated solution of proton exchange membrane fuel cells, respectively. Meanwhile, the potentiostatic polarization test shows that the corrosion current density of the composite coating is below 1 μA cm −2 under real PEMFC working conditions of the cathode (0.6 V) and anode (−0.1 V). Additionally, the composite coating enhances hydrophobic property with a static contact angle of 120.2°and 115.5°before and after polarization test, respectively. In summary, the Ti substrate with carbon/PTFE/TiN composite coating shows a great potential application as bipolar plates of PEMFCs.
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CHINESE JOURNAL OF CATALYSIS
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2015
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IF 1.964
Wenchao Ren,Zile Hua,Tongguang Ge,Xiaoxia Zhou,Lisong Chen,Yan Zhu,Jianlin Shi
Hierarchically structured Ti-β zeolites were prepared using a two-step post-synthesis approach. The physicochemical properties of the resultant Ti- m β-S x materials were determined using various techniques, including X-ray diffraction, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy, and ultraviolet-visible and ultraviolet-Raman spectroscopies. The porous structures of the synthesized hierarchical Ti-β zeolites were well preserved. Their catalytic performance was compared with that of pure microporous Ti-β materials using alkene epoxidation as a model reaction. It was found that although comparable catalytic activities were obtained for both types of catalyst in the epoxidation of small molecules, e.g., cyclohexene, the synthesized hierarchical Ti-β gave an enhanced catalytic performance in the epoxidation of bulky 1-dodecene.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2017
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IF 4.233
Jian Mei,Wenjun Huang,Zan Qu,Xiaofang Hu,Naiqiang Yan
Ti-modified Co 3 O 4 catalysts with various Co/Ti ratios were synthesized using the co-precipitation method and were used in catalytic oxidation of dibromomethane (CH 2 Br 2 ), which was selected as the model molecule for brominated volatile organic compounds (BVOCs). Addition of Ti distorted the crystal structure and led to the formation of a Co-O-Ti solid solution. Co 4 Ti 1 (Co/Ti molar ratio was 4) achieved higher catalytic activity with a T 90 (the temperature needed for 90% conversion) of approximately 245 °C for CH 2 Br 2 oxidation and higher selectivity to CO 2 at a low temperature than the other investigated catalysts. In addition, Co 4 Ti 1 was stable for at least 30 h at 500 ppm CH 2 Br 2 , 0 or 2 vol% H 2 O, 0 or 500 ppm p-xylene (PX), and 10% O 2 at a gas hourly space velocity of 60,000 h −1 . The final products were CO x , Br 2 , and HBr, without the formation of other Br-containing organic byproducts. The high catalytic activity was attributed to the high Co 3+ /Co 2+ ratio and high surface acidity . Additionally, the synergistic effect of Co and Ti made it superior for CH 2 Br 2 oxidation. Furthermore, based on the analysis of products and in situ DRIFTs studies, a receivable reaction mechanism for CH 2 Br 2 oxidation over Ti-modified Co 3 O 4 catalysts was proposed.
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PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2024
·
IF 3.2
Ziqiang Zhang,Zhengfeng Shen,Chuanyu Zhu,Yunfang Wang,Yawen Wang,Caimei Fan,Rui Li,Jianxin Liu
Producing hydrogen from organic/inorganic hydrides is an innovative clean energy alternative to fossil fuels , addressing the increasing energy demands. Here, we first propose coupled photocatalytic water hydrogen production and N,N-dimethylformamide (DMF, C 3 H 7 NO) dehydrogenation technology to obtain high value-added H 2 and N,N-dimethylcarbamic acid (C 3 H 7 NO 2 ). ZnIn 2 S 4 @MIL-125(Ti) nanoheterostructures were synthesized using a simple solvothermal method and resulting in a photocatalytic H 2 production rate of 2.135 mmol h −1 g −1 (apparent quantum efficiency at 380 nm was 2.6 %) which is 2.77 times higher than pure ZnIn 2 S 4 . Liquid-phase mass spectrometry indicates that the DMF oxidation activity of ZIS@MIL heterojunction is double pure ZnIn 2 S 4 and only microcrystalline CO 2 is produced. Isotopes indicate that the production pathway of H 2 results from the coupling of the –CHO bond in DMF and the –H in water. The improved photocatalytic activity of the ZnIn 2 S 4 @MIL-125(Ti) heterostructure is attributed to facilitating efficient charge carrier transfer and separation and DMF depletion of holes accelerates electron transfer .
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高影响因子
FUEL
·
2024
·
IF 6.7
Yang Liu,Shaokai Ma,Shiqing Zhang,Fang Liu,Ying Wang,Xinyu Sun,Ying Li,Yanming Xue,Chengchun Tang,Jun Zhang
Efficient and sustainable hydrogen production via water electrolysis relies on the utilization of highly active electrocatalysts for the oxygen evolution reaction (OER). Birnessite (δ-MnO 2 ), a type of manganese oxide with a local atomic structure similar to the oxygen-evolving complex in photosystem II, has emerged as a highly promising OER catalyst. Despite considerable efforts have been dedicated to enhancing its activity, the crucial aspect of stability has been often overlooked. Herein, Ti ions have been selectively incorporated into the in-layered lattice of δ-MnO 2 nanosheet arrays using a hydrothermal method, aiming to enhance the stability without reducing its activity. The resulting optimal Ti-MnO 2 catalyst demonstrates enhanced OER activity in alkaline electrolyte, exhibiting an impressive 85 mV reduction in overpotential at 10 mA cm −2 , surpassing the initial MnO 2 (495 mV reduced to 410 mV). Remarkably, it shows exceptional durability, with negligible performance decrease observed over the entire 50-hour testing period. It has been demonstrated that the incorporation of Ti serves a dual purpose: it adjusts the electronic structure around Mn, enhancing activity, and simultaneously stabilizes the Mn 3+ active sites, resulting in exceptional durability. Furthermore, density functional theory (DFT) calculations provide additional confirmation of the optimized electronic structure of MnO 2 achieved through Ti doping, leading to a reduction in the free energy of adsorbed intermediates and expediting the kinetics of the OER process. Our findings open a pathway for enhancing OER stability and activity by doping electrocatalytic inert ions into the lattice of MnO 2 , applicable not only to Mn-based oxides but also other non-precious metal-based electrocatalysts.
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高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2025
·
IF 6.1
Jiaxing Li,Jiongming Chen,Ying Chen,Jialei Ren,Jianan Li,Liankui Wu,Hongwei Liu,Fahe Cao,Qingqing Sun
This study develops a new shot peening method, i.e., copper powder ultrasonic shot peening, and investigates its antibiofouling effect on commercially pure titanium grade 2 (TA2) alloy in seawater. The results indicate that adding Cu powder during ultrasonic shot peening can form a Cu-containing layer with a thickness 1–2 μm on the surface of TA2 alloy, primarily in the form of nanocrystals. This Cu-containing layer exhibits a 90 % antifouling efficiency against Pseudomonas aeruginosa and an 85 % efficiency against Aspergillus terreus , mainly due to the release of Cu ions during immersion. Electrochemical corrosion test results show that corrosion rate of this anti-fouling layer is two orders of magnitude higher than the substrate alloy, which significantly enhances the release of Cu ions and thereby improving the antifouling capability. Tensile test results show that Cu powder peening similarly improves the mechanical properties of TA2 alloy as conventional peening.
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高影响因子
危险品化学品经营许可证（带存储）