ACS Nano
·
2019
·
IF 13.903
Huihui Liu,Yue Li,Miaomiao Xiang,Hualing Zeng,Xiang Shao
Interfacial charge transfer is critical for the photocatalytic activities of compositional photocatalysts. In this work, we have developed a strategy of growing single-layer MoS2 sheets on the rutile TiO2(110) single-crystal surface using a chemical vapor deposition method. Both on-site and off-site characterizations confirmed the monolayer thickness and single crystallinity of the MoS2 adlayer as well as the atomic flatness of the composite surface. Without the presence of contamination, the charge flow across the interface of MoS2 and TiO2 is greatly enhanced, which hence favors the charge separation under excitations and boots up the catalytic activity of the composite system. Moreover, we found the luminescing property of MoS2 is significantly tailored upon coupling with the TiO2 surface. Our work has established a method for revealing the interface properties of the transition-metal dichalcogenides and oxide semiconductors at the atomic level.
研究领域:
材料科学
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物理化学
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产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2020
·
IF 3.333
Naveed Athir,Sayyed Asim Ali Shah,Farooq Khurum Shehzad,Jue Cheng,Junying Zhang,Ling Shi
Zwitterion polyurethanes (ZPU) are used for non-fouling and antimicrobial surfaces but their sensitive nature under ultra-violet (UV) radiations limits the requirements of engineering materials . Herein, ZPU is successfully synthesized and then prepared different TiO 2 /ZPU composites, aiming to increase the service life of ZPU and to form active film for food packaging applications. The thermo-mechanical results revealed that the 4% TiO 2 /ZPU sample exhibits better performance, as evidenced through tensile testing and surface morphology analysis. The UV–Vis spectra results indicated that the rutile TiO 2 nanoparticles can enhance the UV absorption and visible light reflectance, decreasing photoaging properties of composites thereby prolonging its shelf life. Moreover, scanning electron microscopy ( SEM) observation after 5 h irradiation of UV light confirmed the photostability of TiO 2 /ZPU composite film . Further, the antioxidant ability of ZPU is increased from 51% to 71% with TiO 2 . The results of antimicrobial activity of TiO 2 /ZPU demonstrate strong bacterial growth inhibition against E. coli that regards its suitability for food and other packaging applications. Besides, the food preservation ability is monitored by visual changes of tomato fruit. In essence, we anticipate that the TiO 2 /ZPU composite films possessed all expected features to be considered as photostable material for food packaging.
研究领域:
材料科学
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高分子科学
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食品科学
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纳米技术
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产品关联
DOI
高影响因子
CHEMICAL COMMUNICATIONS
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2014
·Vol. 50
·期 21
·2755-2757
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IF 6.718
Zhao Zhao,Huaqiao Tan,Haifeng Zhao,Yang Lv,Li-Jing Zhou,Yujiang Song,Zaicheng Sun
Stable reduced TiO2 rutile nanorods with well-defined facets were prepared by a solvothermal route in the presence of Zn powder. The oxygen vacancy in the TiO2 nanorods, which can be tuned by the amount of Zn, results in a narrow band gap and visible-light photocatalytic activity.
研究领域:
材料科学
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化学
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DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
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2019
·
IF 5.714
Xiangjie Chen,Ya Zhu,Kun Yang,Lizhong Zhu,Daohui Lin
Little information is available about effect of particle size and crystal structure of nTiO 2 on their trophic transfer. In this study, 5 nm anatase , 10 nm anatase, 100 nm anatase, 20 nm P25 (80% anatase and 20% rutile), and 25 nm rutile nTiO 2 were selected to investigate the effects of size and crystal structure on the toxicity, bioconcentration, and trophic transfer of nTiO 2 to algae and daphnia. In the exposed daphnids, metabolic pathways affected by nTiO 2 and nTiO 2 -exposed algae (nTiO 2 -algae) were also explored. The 96 h IC 50 values of algae and the 48 h LC 50 values of daphnia were 10.3, 18.9, 43.9, 33.6, 65.4 mg/L and 10.5, 13.2, 37.0, 28.4, 60.7 mg/L, respectively, after exposed to nTiO 2 -5A, nTiO 2 -10A, nTiO 2 -100A, nTiO 2 -P25, and nTiO 2 -25R, respectively. The bioconcentration factors (BCFs) for 0.1, 1, and 10 mg/L nTiO 2 in daphnia ranged from 21,220 L/kg to 145,350 L/kg. The nTiO 2 biomagnification factors (BMFs) of daphnia fed with 1 and 10 mg/L nTiO 2 -exposed algae were consistently greater than 1.0 (5.7–122). The results show that the acute toxicity, BCF, and BMF all decreased with increasing size or rutile content of nTiO 2 . All types of nTiO 2 were largely accumulated in the daphnia gut and were not completely depurated within 24 h. At the molecular level, 22 Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways of daphnia were impacted by the nTiO 2 and nTiO 2 -algae treatments, including glutathione metabolism, aminoacyl-tRNA biosynthesis, among others. Six and four KEGG metabolic pathways were significantly disturbed in daphnids exposed to nTiO 2 and nTiO 2 -algae, respectively, indicating the presence of algae partially alleviated the negative impact of nTiO 2 on metabolism. These findings increase understanding of the impacts of physicochemical properties of nTiO 2 on the food chain from molecular scale to that of the whole organism, and provide new insight into the ecological effect of nanomaterials .
研究领域:
环境科学
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毒理学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Yuemiao Lai,Zhengtian Pu,Peng Liu,Fangliang Li,Jie Zeng,Xueming Yang,Qing Guo
The low-temperature C–H bond activation of alkanes remains a big challenge in alkane dehydrogenation. In this work, ethylbenzene (EB) oxidative dehydrogenation has been investigated on rutile(R)-TiO2(110) under both ultrahigh vacuum (UHV) and ambient conditions. Under UHV conditions, styrene is produced with nearly 100% selectivity in a stepwise manner, in which the first C–H bond dissociation of EB occurs at <285 K with the help of surface O22– species, followed by the second C–H bond dissociation at about 400 K. However, styrene, acetophenone, and 2,3-diphenylbutane products are produced from EB oxidative dehydrogenation under ambient conditions, suggesting that α-H dissociation is the initial step of EB oxidative dehydrogenation. This may be also possible for EB oxidative dehydrogenation on R-TiO2(110) under UHV conditions. The different pathways of EB oxidative dehydrogenation under UHV and ambient conditions may originate from different intermediates and O2 concentrations. This work provides new insight into the fundamental understandings of the low-temperature C–H bond activation of alkyl chains of aromatic hydrocarbons, which may promote the development of new catalysts for efficient styrene production from EB oxidative dehydrogenation under mild conditions.
研究领域:
催化化学
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表面科学
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产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Cong Fu,Lingfang Liu,Xuelin Fan,Guofeng Zhao
Tracking the concentrations of surface-reaching photoexcited charges in photocatalysis is of great importance to fundamental science. Herein, through combining in situ and time-resolved diffuse-reflectance infrared spectroscopy (DRIFTS), we report an adsorbed methanol species surface elementary reaction kinetic analysis method. This strategy allows us to track the concentration of surface-reaching photoholes in well-defined anatase TiO2 nanoparticles, and compare it with that of rutile TiO2 nanoparticles. The photocatalytic oxidation of adsorbed methanol species on different TiO2 crystal phase surface follows first-order reaction kinetics. Thus, the corresponding rate constants of adsorbed methanol species have been acquired, which could directly mirror the concentration of surface-reaching photoholes under light irradiation. Based on the specific value of the reaction rate constant of adsorbed methanol species on different TiO2 crystal phase surface, for the first time, it can be concluded that concentration of surface-reaching photoholes in anatase is nearly 3.3 times greater than that of rutile under light irradiation. These results newly illustrate why anatase usually exhibits higher photocatalytic activity than rutile. Meanwhile, this work highlights that probing molecules in a surface elementary reaction kinetic analysis based on in situ and time-resolved DRIFTS could be utilized as an effective method to track the concentration of surface-reaching photoexcited charges in photocatalysis as well as other similar kinds of catalytic processes.
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产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Lei Xiao,Lianwen Deng,Yingxiang Li,Zhenjun Qing,Yecheng Xi,Jiahui Zhu,Sen Peng
TiSnNbTaGa 2 O 12 (TSNTGO) high–entropy dielectric ceramic was successful synthesized using the solid-state reaction method. X–ray diffraction (XRD), Rietveld refinement and transmission electron microscopy (TEM) were used to verify that all samples have rutile structure of P42–mnm space group. The analysis of Raman spectra proved that the ε r exhibited a contrary changing trend as that of Raman shift near 822 cm −1 , and the same similar relationship occurred between Q×f values and full width at half maximum (FWHM). The exploration of complex chemical bonding theory (P–V–L theory) for TSNTGO ceramics suggested that the bond ionicity played a dominant role in ε r , while Q×f and τ f were primarily determined by lattice energy and bond energy, respectively. Notably, the TSNTGO ceramics sintered at 1275 ℃ demonstrated optimal microwave dielectric properties of ε r = 33.62 ± 0.03, Q×f = 51,832 ± 1000 GHz ( f 0 = 6.4 GHz), and τ f = –0.38 ± 0.16 ppm/℃.
研究领域:
材料科学
·
固态物理
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Siyu Gong,Ting Zhang,Bingguo Liu,Peng Liu,Yifan Niu,Zhenxing Yang,Yuhao Jin,Wang Chen,Guangxiong Ji,Shenghui Guo,Libo Zhang
The study introduces a microwave-assisted rutile seed crystal (RS) method to synthesise mixed-phase TiO 2 nanoparticles, controlling the rutile TiO 2 (TiO 2 -R) phase content ( γ R ) from 33.0 % to 99.3 % by adjusting the doping level of RS to 20.0 wt% in the metatitanic acid (MA). The sample, designated as MA-20, with the highest oxygen vacancy (O v ) concentration of 38.56 %, demonstrated over 99 % microwave absorption (minimum reflection loss ( R L ) −56.8 dB) and a heating rate of 0.836 °C/s under 2000 W and 20 g. RS enhanced the dielectric property of MA, facilitating phase transition from anatase TiO 2 (TiO 2 -A) to TiO 2 -R above 600 °C, with critical temperatures between 800 and 1000 °C. MA-20, with a surface area of 1.9226 m 2 /g and pore size distribution of 9.0851 nm, showed that higher RS doping levels promoted phase transition and grain growth, thereby enhancing the crystallinity and charge transfer efficiency. More than 50 % of MA-20 particles were under 10 nm, and 94 % were below 100 nm, confirming the synthesis of TiO 2 nanomaterials. MA-20 exhibited excellent electromagnetic wave storage and conversion properties. Adjusting microwave parameters and RS levels controls γ R , offering an efficient approach for preparing mixed phase TiO 2 catalysts, essential for semiconductor photocatalysis and overcoming TiO 2 -A limitations.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Jingjing Wang,Chenxi Huang,Yue Xing,Xiang Shao
The hybridizations of two-dimensional (2D) metallic materials with semiconducting transition metal oxides (TMOs) register attractive heterojunctions, which can find various applications in photostimulated circumstances. In this work, we developed an ambient-pressure chemical vapor deposition method to directly grow T-VS2 on atomically smooth rutile TiO2 single crystals with different terminations and thus successfully constructed a heterojunction model of VS2/TiO2 with a well-defined clean interface. Detailed measurements with Kelvin probe force microscopy revealed the facet-dependent charge transfer occurring at the VS2/TiO2 interfaces, seeing variations not only in the amount and direction of the transferred electrons but also in the photoinduced surface potential changes and the dynamics of photogenerated charge carriers under ultraviolet irradiation. Interestingly, ultrathin T-VS2 was found with considerable magnetism at room temperature, disregarding the charge exchange with the TiO2 substrates. These results may bring deep insights into the photoinspired functionalities of the hybridized system combining metallic transition metal dichalcogenides and TMO materials.
研究领域:
材料科学
·
纳米技术
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光化学
·
表面科学
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产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 11
·3709-3719
·
IF 5.721
Chengwei Qiu,Jinjin Lin,Jinni Shen,Dan Liu,Zizhong Zhang,Huaxiang Lin,Xuxu Wang
Anatase/rutile TiO2 heterophase junction composites have been documented to have much higher photocatalytic activity than single phase TiO2 (nude anatase or nude rutile) for various chemical reactions, including hydrogen production from methanol–water solution and pollution degradation. Further improving the photocatalytic performance of heterophase junction photocatalysts is a subject worth studying in both theory and practice. Based on the concept of junction interface regulation and our previous findings, we embedded Ni12P5 nanoparticles at the interface between anatase (A) and rutile (R) TiO2 by a multi-step preparation method to obtain an A/Ni12P5/R composite with a sandwich-like structure. It was found that loading Ni12P5 on the outside surface of anatase TiO2 (Ni12P5/A), rutile TiO2 (Ni12P5/R), P25 TiO2 (Ni12P5/P25), and A/R composite (Ni12P5/A/R) leads to a decrease in the photocatalytic activity; however, interestingly, the A/Ni12P5/R sample showed higher photocatalytic activity than the other samples of loaded or unloaded Ni12P5, although the loaded Ni12P5 in the latter case is inaccessible to the reactant molecules. This abnormal phenomenon can be attributed to two main reasons. (i) Ni12P5 as a metal-like material has a higher work function than anatase and rutile, which leads to the formation of Schottky junctions at the interface between the two intimately contacted phases. (ii) When Ni12P5 is located on the outside surface, the Schottky junction is unfavorable for the transfer of photogenerated electrons from TiO2 to Ni12P5. However, when Ni12P5 is sandwiched between A and R, the formation of a reverse tandem Schottky junction can facilitate the directed transfer of photogenerated electrons from R phase to A phase. This work again verifies that photocatalytic activity can be regulated and controlled by introducing metal and metal-like particles within the junction of a metal/semiconductor interface or even on a semiconductor/semiconductor interface. Our findings not only provide a novel usage of Ni12P5 as a co-photocatalyst but also deepens the understanding of the Schottky effect on the photocatalytic process.
研究领域:
材料科学
·
光催化
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Miaomiao Xiang,Chenxi Huang,Yue Xing,Huihui Liu,Xiang Shao
Hybridization with oxide semiconductors provides a versatile strategy for tailoring physicochemical properties of two-dimensional materials (2DMs). However, the direct impacts of specific interface interactions have not yet been very well categorized, in particular at an atomic level. In the present work, through a chemical vapor deposition (CVD) method, we successfully grew monolayer MoS2 flakes on an atomically smooth rutile TiO2 single crystal with (100), (110), and (001) terminations. We found that the fabrication of comparable high-quality MoS2 on all of the TiO2 substrates can only be achieved via finely varying the growth parameters. Moreover, the photoluminescence of MoS2 also changes against the substrate terminations, showing a gradually reduced A0/A– exciton ratio following the sequence of (100) > (110) > (001). Detailed X-ray photoelectron spectroscopy measurements showed the same tendency for the binding energy shifts of both Ti and O in the MoS2/TiO2 samples, which were attributed to the varied dipole fields established at the MoS2/TiO2 interfaces. Our work not only reinforces the important role of interface charge redistribution in tailoring the properties of hybridized systems but also emphasizes that the facet effect may be applied as an efficient strategy for optimizing the photocatalytic activities of compositional systems.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ying Xue,Zhuo Wang,Jinteng Kang,Caidan Hou,Ronghui Ye,Ting Zhao,Xin Li
TiO 2 -based colossal dielectric ceramics have emerged as a prominent research focus in recent years. However, their further applications have been constrained by several key limitations, including the requirement of high sintering temperature (>1400 °C), relatively high dielectric loss (>0.05, 1 kHz), and temperature stability (<200 °C). This study reports rutile (In 0.5 Ta 0.5 ) 0.1 Ti 0.87 O 1.88 F 0.12 ceramics at 1220 °C sintering using 12 % InF 3 as the acceptor In 3+ source, which exhibits a colossal dielectric constant (1.1 × 10 5 ) and an ultra-low dielectric loss (0.0071) at 1 kHz and room temperature, even loss values below 0.04 (20 Hz - 100 kHz). Notably, the thermal stabilities (10 kHz, 100 kHz) simultaneously satisfy X9E (Δε r /ε 25 °C ≤ ±4.7 %) above 300 °C. F − not only supplies electrons to enhance the semiconductivity of grains, but also decreases the oxygen vacancy and average grain size (270 ± 12.53 nm) to improve grain boundaries resistances, which reduces dielectric loss and enhances frequency and temperature stabilities. As a result, the dielectric mechanism is mainly related to internal barrier layer capacitor (IBLC) and high grain boundary resistance. Therefore, this strategy provides a creative design for developing TiO 2 -based ceramics.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）