MICROPOROUS AND MESOPOROUS MATERIALS
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2021
·
IF 5.455
Zijun Yang,Qiang Yu,Yonghua Guo,Xiaoxia Wu,Hua Wang,Jinyu Han,Qingfeng Ge,Xinli Zhu
Heteroatom metal-zeolite, with heteroatom metal (oxide) dispersed in the zeolite framework, enables the reactions typically catalyzed by bulk metal oxide counterpart but with maximized the atomic utilization. However, the distribution of heteroatoms in the framework is strongly influenced by the preparation method. In this work, Ti-Beta zeolites were postsynthesized using the recrystallization (Ti-Beta-Re) and solid-state ion-exchange (Ti-Beta-SSIE) methods. Characterizations showed that more Ti species were incorporated in the tetrahedral framework site of Ti-Beta-Re to form Lewis acid sites than in that of Ti-Beta-SSIE. In addition, intra-crystallite mesopores were developed in Ti-Beta-Re due to partial dissolution of BEA framework during alkaline etching and subsequent recrystallization of the etched framework. These zeolites were then tested for ketonization of biomass derived propionic acid at 350 °C and atmospheric pressure. The turnover frequency of ketonization was found to be 25% higher on Ti-Beta-Re (0.25 min −1 ) than on Ti-Beta-SSIE (0.20 min −1 ), whereas the apparent activation energy of 80 kJ/mol on Ti-Beta-Re is lower than 95 kJ/mol on Ti-Beta-SSIE. Moreover, the selectivity of 3-pentanone kept > 95% on Ti-Beta-Re while it dropped to ∼63% on Ti-Beta-SSIE with increase of reaction time at a space time of 2 h. This work demonstrated that the tetrahedrally coordinated Ti species are the active sites and the presence of intra-crystallite mesopores facilitates selective ketonization of carboxylic acids.
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高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Longwen Li,Lin Chi,Hongxu Zhang,Shuming Wu,Han Wang,Zhimin Luo,Yanwei Li,Yanhui Li
This article prepared a nanoparticle (NP) Ti-PDA made from bis (2-hydroxy propionic acid) diammonium titanium hydroxide (Ti-BALDH) chelating dopamine (DA), as a photocatalyst to absorb and reduce hexavalent chromium (Cr(VI)) under visible light with recycling ability from waste water. Ti-PDA NPs with part of TiO 2 -like structure can perform some function of TiO 2 , while participation of PDA will not only broaden absorption spectrum from UV to visible light, but offer the ability to absorb Cr(VI). Compared with TiO 2 Ti-PDA NPs would make full use of sunlight, increasing the photocatalytic efficiency. The adsorption results of Ti-PDA NPs for Cr(VI) showed that the adsorption capacity of Ti-PDA NPs can reach 500.24 mg/g when the concentration of Cr(VI) was 300 mg/L, and the adsorption data matched well with the Langmuir isotherm model, and confirmed to a quasi-second-order dynamics. Under visible light irradiation, Ti-PDA NPs could reduce Cr(VI) to Cr(III) within 30 min, and can almost completely reduce Cr(VI) within 15 min even at pH = 4. After three cycles, photocatalytic reduction efficiency was still 95.02%. Thereby the toxic Cr(VI) can be effectively eliminated by Ti-PDA NPs from sewage. As a result, Ti-PDA will be a promising green photocatalyst to remove Cr(VI) in disposal of water pollution.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
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IF 7.312
Lei Xu,Shaoyu Tang,Dan Li,Xiao Ma,Yunqing Zhu,Jianjiang Lu,Junfeng Niu
The current study presents a comprehensive and novel attempt to degrade aqueous tri(2-chloroethyl) phosphate (TCEP) by metal-oxide-coated Ti anodes for the first time. Six metal-oxide-coated Ti electrodes (Ti/SnO 2 -Sb, Ti/SnO 2 -Sb/PbO 2 , Ti/SnO 2 -Sb/La-PbO 2 , Ti/SnO 2 -Sb/Ce-PbO 2 , Ti/SnO 2 -Sb/Ga-PbO 2 and Ti/SnO 2 -Sb/Zr-PbO 2 ) were prepared and characterized. Ti/SnO 2 -Sb/La-PbO 2 showed the highest pseudo-first-order reaction rate constant (2.1 × 10 −2 min −1 ) and lowest energy consumption (21.35 Wh L −1 ) in the degradation of 1 mg L −1 TCEP at 10 mA cm −2 , mainly because of its highest oxygen evolution potential and OH production. Higher current density and neutral condition favored TCEP degradation, while the presence of Cl − or NO 3 − could suppress the degradation. In the electrochemical degradation of 10 mg L −1 TCEP, mineralization percentage of 48.0% (mineralization current efficiency of 0.30%) and PO 4 3− release percentage of 72.7% were achieved at 150 min. By the attack of OH on the C O and C Cl bonds in TCEP molecular structure, products of chloroethanol, Cl − and PO 4 3− were released, with the major electrocatalytic degradation pathways of dechlorination and hydroxylation. Based on the results of flow cytometry, the relative toxicity to Escherichia coli effectively decreased to 4.93% in TCEP degradation. Compared with the UV-AOPs, electrochemical oxidation process is proved to be feasible and effective for mineralization and detoxification of TCEP in water.
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JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2020
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IF 6.155
Kun Wang,Xian Tong,Jixing Lin,Aiping Wei,Yuncang Li,Matthew Dargusch,Cuie Wen
Zinc (Zn) and its biocompatible and biodegradable alloys have substantial potential for use in orthopedic implants. Nevertheless, pure Zn with a hexagonal close-packed crystal structure has only two independent slip systems, therefore exhibiting extremely low elongation and yield strength in its as-cast condition, which restricts its clinical applications. In this study, as-cast Zn–xTi (titanium) (x = 0.05, 0.10, 0.20, and 0.30 wt.%) binary alloys were hot-rolled and their microstructures, mechanical properties , wear resistance, and cytocompatibility were comprehensively investigated for orthopedic implant applications. The microstructures of both as-cast and hot-rolled Zn–xTi alloys consisted of an α-Zn matrix phase and a TiZn 16 phase, while Zn–0.2Ti and Zn–0.3Ti exhibited a finer α-Zn phase due to the grain-refining effect of Ti. The hot-rolled Zn–0.2Ti alloy exhibited the highest yield strength (144.5 MPa), ultimate strength (218.7 MPa), and elongation (54.2%) among all the Zn–xTi alloys. The corrosion resistance of Zn–xTi alloys in Hanks’ solution decreased with increasing addition of Ti, and the hot-rolled Zn–0.3Ti alloy exhibited the highest corrosion rates of 432 μm/y as measured by electrochemical testing and 57.9 μm/y as measured by immersion testing. The as-cast Zn–xTi alloys showed lower wear losses than their hot-rolled counterparts. The extracts of hot-rolled Zn–xTi alloys at concentrations of ≤ 25% showed no cytotoxicity to MG-63 osteosarcoma cells and the extracts of Zn–xTi alloys exhibited enhanced cytocompatibility with increasing Ti content.
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2020
·Vol. 96
·期 2
·431-440
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IF 2.008
Cao Ensi,Feng Yibiao,Guo Zhaoqing,Wang Huihui,Song Guoqing,Zhang Yongjia,Hao Wentao,Sun Li,Nie Zhongquan
To further improve the ethanol sensing performance of LaFeO 3 (LFO) nanoparticles, the co-doping of acceptor and donor at La and Fe sites at equal mole amount was designed to increase the oxygen adsorbing ability of the resultant nanoparticles. A series of (La,Ba)(Fe,Ti)O 3 nanoparticles, with the designed mole ratios of Ba/La (Ti/Fe) as 0, 0.25, 0.33, 0.50, and 1.0, were prepared by a citric sol–gel method. XRD confirmed the main phase of orthorhombic LFO, and the impurity phases of cubic BaTiO 3 (BTO) and orthorhombic BaCO 3 . The incorporation of Ba and Ti into the LFO lattice was verified by the increased unit cell volume of LFO upon more doping. TEM, BET, and XPS measurements indicated that the appropriate co-doping of Ba and Ti into the LFO lattice and the simultaneous existence of BTO and BaCO 3 resulted in smaller grain size, larger BET surface area, and thus higher concentration of adsorbed oxygen species than those in the pristine LFO nanoparticle. Among all (La,Ba)(Fe,Ti)O 3 sensors, the sensor based on the (La,Ba)(Fe,Ti)O 3 nanoparticles with the designed Ba/La = 0.50 exhibited the highest gas response and sensitivity toward ethanol at the prime working temperature of 132 °C, which was ascribed to the higher surface oxygen coverage contributed by the synergistic effect of co-doping and impurity phases on the number of surface active sites and oxygen adsorbing ability.
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INORGANIC CHEMISTRY COMMUNICATIONS
·
2019
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IF 1.795
Yu Guo,Jie Li,Xuanxuan Yang,Yongbing Lou,Jinxi Chen
Hydrogen production by photocatalysis under visible light irradiation is a pivotal means of obtaining hydrogen. In this study, Zn 0.5 Cd 0.5 S was studied to have optimal hydrogen production performance among different zinc-cadmium ratios of Zn x Cd 1-x S, and a series of Zn 0.5 Cd 0.5 S/MIL-125-NH 2 (Ti) composites with different MIL-125-NH 2 (Ti) contents were prepared by simple ultrasonic method. When the percentage of addition of MIL-125-NH 2 (Ti) was 40%, the optimum hydrogen production rate was 92,498 μmol h −1 g −1 , and the photocatalytic activity was still stable even after 16 h. The mechanism investigations demonstrated that this excellent activity was owing to enhanced visible light absorption intensity, extremely efficient electron transfer and proper conduction band position. This work provides new insights into highly efficient and stable photocatalyst in hydrogen production from water without noble metal doping.
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高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 12
·1795
·
IF 4.034
Ya Song,Zhiyu Zhang,Lamei Yan,Ling Zhang,Simin Liu,Shaowen Xie,Lijian Xu,Jingjing Du
In this paper, a novel Ti-doped hierarchically mesoporous silica microspheres/tungsten oxide (THMS/WO3) hybrid film was prepared by simultaneous electrodeposition of Ti-doped hierarchically mesoporous silica microspheres (THMSs) and WO3nanocrystallines onto the fluoride doped tin dioxide (FTO) coated glass substrate. It is demonstrated that the incorporation of THMSs resulted in the hybrid film with improved electrochromic property. Besides, the content of THMSs plays an important role on the electrochromic property of the hybrid film. An excellent electrochromic THMS/WO3hybrid film with good optical modulation (52.00% at 700 nm), high coloration efficiency (88.84 cm2C−1at 700 nm), and superior cycling stability can be prepared by keeping the weight ratio of Na2WO4·2H2O (precursor of WO3):THMSs at 15:1. The outstanding electrochromic performances of the THMS/WO3hybrid film were mainly attributed to the porous structure, which facilitates the charge-transfer, promotes the electrolyte infiltration and alleviates the expansion of the film during Li+insertion. This kind of porous THMS/WO3hybrid film is promising for a wide range of applications in smart homes, green buildings, airplanes, and automobiles.Keywords:Ti-doped hierarchically mesoporous silica;electrochromic;electrodeposition;tungsten oxide;hybrid film
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PubMed
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Jie Ji,Heng Xu,Haozhe Li,Xiandie Zhang,Xiang Ke,Xinwen Ma,Xiaode Guo,Xiang Zhou
With the development of traditional aluminum(Al)-based nanothermites, some problems on account of the metal Al powder gradually emerged. Therefore, extensive research is devoted to exploring novel metal fuels to achieve better energy release effects. Titanium (Ti) powder is a potential metal fuel theoretically considering of reducibility and calorific value , but it has rarely been reported in the field of nanothermites. This paper put forward the design strategy by selecting as the metal fuel and polyvinylidene fluoride (PVDF) as oxidant. According to the hydrophilicity of Ti powders, the PVDF film encapsulation can effectively improve hydrophobicity and storage stability. Another advantage of PVDF film state is that it imparts excellent mechanical properties (yield strength of 30.5 MPa and elongation at break of 202.8 %). According to the results of thermal analysis, Ti increased the thermal stability of PVDF while accelerated its thermal decomposition rate. In ignition properties, Ti-PVDF films have the shortest ignition delay time (217 ms) lower than results reported in the literature of other nanothermites under the same conditions. In addition, the energy release process of ignition combustion is analyzed and verified in this paper. Therefore, Ti-PVDF energetic ignition material with diverse properties is expected to be applied in more fields not limited to nanothermites.
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Journal of Materials Research and Technology-JMR&T
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2023
·
IF 6.4
Bo Dong,Chengji Deng,Jun Ding,Hongxi Zhu,Qian Wang,Yong Zhang,Chao Yu
In this investigation, we have employed a novel approach to fabricate β–Sialon/Ti(C, N) composites through the nitridation treatment of Ti 3 SiC 2 powder. At temperatures ranging from 1373 to 1773 K, the reaction process was subjected to a comprehensive analysis to explore the transformation of phase and microstructure. The findings unequivocally highlight the influence of α–Al 2 O 3 presence and the high specific surface area of Ti 3 SiC 2 powder, resulting in distinctive phase and structural evolutions post nitridation, distinctly different from those observed in bulk Ti 3 SiC 2 . The β–Sialon/Ti(C, N) composites produced via this innovative method exhibit uniform local chemical composition and meticulous regulation of grain morphology. Moreover, the synthesis mechanism of β–Sialon/Ti(C, N) composites under nitrogen ambiance was thoroughly discussed. This straightforward approach has the potential for extensive–scale synthesis of β–Sialon/Ti(C, N) composites, offering promising avenues for their application in developing high–performance refractories or structural ceramics tailored to withstand severe high–temperature environments.
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高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Yongjin Chen,Hui Ren,Xinzhou Wu,Haoyue Xin,Qingjie Jiao
To design and prepare multifunctional metastable intermixed composites (MICs) with excellent properties, the enhanced “litchi-like” core-shell structure Al/Ti/CuO MICs were prepared by high-energy ball milling (Al/Ti/CuO-B). The morphology, structure, composition, thermal reactivity, energy release and combustion performance of the prepared MICs were investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and synchronous thermal analysis (DSC-TG), closed system constant volume combustion experiment, open system CO 2 laser ignition experiment and high-energy laser-induced ablation experiment. This study reveals that, the obtained Al/Ti/CuO-B composites have a “litchi-like” core-shell structure, the components are evenly distributed and closely contacted. The exothermic reaction of Al/Ti/CuO-B should be divided into two stages. Due to the introduction of Ti and the special structure of litchi, Al/Ti/CuO-B has superior reactivity ( E a =178.15 kJ/mol), energy release ( Q = 6443 J/g, P max =164.90KPa), shock wave propagation ( v = 1028.33 m/s) and combustion performance than Al/Ti/CuO-P (simple physical mixing). The thrown Al/Ti/CuO composite particles will undergo secondary micro-reactions during the combustion, and a continuous multi-point “micro-explosion” phenomenon will occur, then self-sustainable combustion can be achieved through multi-level energy superposition release, which will enhance its reaction, combustion and energy release. Al/Ti/CuO-B undergoes an ultrafast reaction to generate plasma under high-energy laser induction, which expands and pushes the surrounding air to form a shock wave. The application of Al/Ti/CuO-B shows that the density, heat of detonation, shock wave overpressure, fireball diameter and temperature of composite structural explosive charge containing Al/Ti/CuO ring are all significantly improved.
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Nature Communications
·
2023
·Vol. 14
·期 1
·1-10
·
IF 16.6
Du Xinze,Fan Hongjun,Liu Shenglin,Zhang Z. Conrad
C−C bond forming reaction by alkylation of aryl rings is a main pillar of chemistry in the production of broad portfolios of chemical products. The dominant mechanism proceeds via electrophilic substitution of secondary and tertiary carbocations over acid catalysts, forming multiple aryl alkylation products non-selectively through all secondary and tertiary carbons in the alkyl chains but producing little α-C alkylation products because primary carbocations are poorly stable. Herein, we report that anatase TiO 2 (TiO 2 -A) catalyzes nucleophilic α-C alkylation of phenols with alcohols in high selectivity to simply linear alkylphenols. Experimental and computational studies reveal the formation of Ti=C− bond with the α-carbon of the alkyl group at oxygen vacancies of the TiO 2 -A surface. The subsequent α-C alkylation by selective substitution of phenol ortho- C−H bond is verified by deuterium exchanged substrate and DFT calculations.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yun-fei Zhang,Jia-le Gao,Shen-gui Chen,Lei Li,Jian-hui Xu,Dan Li,Yu-feng Liu,Xin Quan,Xin Fu,Ya-zi Xie,Jing-nan Wu,Dan-ying Lin,Ting-ting Zheng
In this study, a novel 3D printed (3DP) Nb 2 O 5 /Ti electrode with a three-dimensional pore structure was prepared using selective laser melting (SLM) 3DP technology. The electrode exhibited high degradation efficiency, low energy consumption (16.02 Wh/L for 90% removal of 5 mg/L of Florfenicol (FLO)), and promising lifetime. Specifically, the 3DP 3% Nb 2 O 5 /Ti electrode maintained a 97.0% degradation efficiency for FLO within 120 min when consecutively used for 20 cycles. It was proposed that the Nb 2 O 5 served as an n-type dopant for Ti (IV), creating an electronegative surface environment that leads to stronger binding of electrons from H 2 O or FLO to the electrode surface. Consequently, the 3D-printed Nb 2 O 5 /Ti electrode exhibits higher OER potential and a greater yield of reactive oxygen species (ROSs) compared to the undoped Ti electrode. The electrode also achieved an 82.5% defluorination ratio for FLO, which is the best dehalogenation yield reported so far. Additionally, the toxicity of intermediates was significantly reduced after electrooxidation treatment, and 11 degradation products were identified by UPLC-MS/MS for potential degradation pathways identification. This study suggests that the 3D printed Nb 2 O 5 /Ti electrode holds great promise in remediating pharmaceuticals and personal care products (PPCPs)-contaminated water, and that SLM 3D printing technology is a beneficial method for producing Ti-stabilized anodes.
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