Journal of Materials Chemistry A
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2018
·Vol. 6
·期 20
·9473-9479
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IF 9.931
Tianjun Zhang,Xiaoxin Chen,Guangrui Chen,Mengyang Chen,Risheng Bai,Mingjun Jia,Jihong Yu
Nano-sized hierarchical titanosilicate TS-1 without extra-framework anatase TiO2 has been successfully synthesized by using Triton X-100 as a mesoporous template under rotational crystallization conditions. The resultant material contains a large external surface area and uniform mesopores (2–4 nm). Notably, the titanium ions are fully incorporated into the framework of TS-1 and no extra anatase TiO2 exists. Triton X-100 and rotational crystallization conditions play an important role in eliminating anatase TiO2. The addition of Triton X-100 slows down the crystallization rate of TS-1, while the rota-crystallization accelerates the incorporation rate of Ti, so that the insertion rate of titanium into the framework matches well with that of silicon. As such, the generation of extra-framework anatase TiO2 can be inhibited. Furthermore, in comparison with nano-sized hierarchical TS-1 prepared under static conditions, nano-sized hierarchical TS-1 prepared under rotational conditions exhibits excellent catalytic activity and high stability in alkene epoxidation, especially in bulky alkene epoxidation. The facile synthetic strategy for nano-sized hierarchical TS-1 without extra-framework anatase TiO2 may open new perspectives for its potential application in selective oxidation reactions involving large molecules.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2014
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IF 3.552
Jian-Wen Shi,Hui-Ying Ai,Jian-Wei Chen,Hao-Jie Cui,Ming-Lai Fu
Composite photocatalysts composed of nitrogen-doped anatase TiO 2 plates with exposed {0 0 1} facets (NTS) and graphene nanosheets (G) were firstly synthesized by a facile one-pot hydrothermal process. The morphologies, structural properties, and photocatalytic activities of the resultant NTS/G composites were investigated in detail. Graphene nanosheets were demonstrated play three important roles in the NTS/G composites, as transporter of photo-excited electrons, extender of light absorption range and enhancer of adsorptive capacity, respectively. Due to the effective charge anti-recombination, the efficient utilization of the visible light and the high adsorptive capacity to target pollutants, the composites exhibited significant improvement in photocatalytic degradation of methylene blue under visible light irradiation. Based on the results, the mechanism of enhanced visible-light photocatalytic activity on NTS/G composites was proposed.
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2016
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IF 8.328
Jinze Lyu,Junxian Gao,Min Zhang,Qiang Fu,Luna Sun,Shuang Hu,Junbo Zhong,Shuo Wang,Ji Li
The separation and injection of photogenerated charge carriers significantly affect the mineralization efficiency of volatile organic compounds (VOCs). These two processes can be optimized by enhancing the separation of charge carriers and the adsorption of VOCs via material engineering. However, obtaining both high adsorption ability and photoactivity of VOCs simultaneously at the ppm level is difficult. In this work, we grew microporous TiO 2 onto the surface of anatase TiO 2 to construct a homojunction-adsorption layer, enhancing both the adsorption and photodegradation of low concentration of toluene, which was chosen as model VOC. N 2 adsorption/desorption, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), GC-flame ionization detection, and surface photovoltage spectroscopy (SPS) were employed to analyze the physical properties and mineralization of toluene. Results showed that growth of microporous TiO 2 increased the surface area of the catalyst by 160% compared with anatase TiO 2 , as well as induced microporous structure. This phenomenon significantly enhanced the adsorption of toluene at a low concentration of 5.5 mg/m 3 and limited the release of the adsorbed organic compounds. Moreover, SPS and XPS results proved that a homojunction was constructed at the interface of microporous TiO 2 and anatase TiO 2 , greatly improving the separation of photogenerated charge carriers. Owing to the enhanced adsorption ability and photoactivity, the mineralization efficiency of toluene over micropore-anatase TiO 2 composite was 1.78 and 2.12 times higher than that over M-TiO 2 and anatase TiO 2 , respectively.
研究领域:
材料科学
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环境催化
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光催化
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纳米材料
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大气污染控制
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DOI
高影响因子
ELECTROCHIMICA ACTA
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2014
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IF 4.086
Hong Tao,Wanping Chen,Jing Wang,Weijun Ke,Jiawei Wan,Jionghua Wu,Guo-jia Fang
Size controllable anatase TiO 2 microspheres with compact nano-aggregate structures are synthesized via a facile and low-temperature solvothermal treatment. The diameters of as-prepared products can be controlled to vary from 250 to 1100 nm. Different kinds of TiO 2 microsphere films are built on the top of TiO 2 nanoparticle underlayer to prepare a type of bi-layer anodes. It is illustrated that this type of TiO 2 microsphere scattering layer can not only increase the absorption of light, but also improve the carrier transport and charge collection efficiency of dye sensitized solar cell (DSSC). Therefore, an optimized efficiency of 8.20% is achieved for DSSC with a scattering layer consisted of 500 nm TiO 2 microspheres. Then we further optimize the interface of TiO 2 microsphere scattering layer through TiCl 4 treatment and Mg 2+ modified TiCl 4 treatment. TiCl 4 treatment can improve the dye adsorption and connections between the TiO 2 microspheres. However, it also generates more surface defects in the meantime. And through the Mg 2+ modified TiCl 4 treatment, we can increase the dye adsorption density and retard the interfacial charge recombination and decrease the surface defects, simultaneously. As a result, the efficiency of DSSC based on bi-layer anode is enhanced from 8.20% to 9.12%.
研究领域:
材料科学
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能源科学
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DOI
高影响因子
ELECTROCHIMICA ACTA
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2012
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IF 3.832
Sujun Yuan,Yaogang Li,Qinghong Zhang,Hongzhi Wang
An anatase TiO 2 sol containing ultrafine TiO 2 crystallites (ca. 5 nm) was used to fabricate the dye-sensitized solar cells (DSSCs) with a compact layer, which was prepared by the peptization–hydrothermal method using the CF 3 COOH as peptizing agent. The dried sol was calcined at 300 °C for 1 h to eliminate the organics over the surface of TiO 2 and increase the crystallite size of the TiO 2 nanocrystals (the special surface area of the calcined TiO 2 decreased from 224.7 to 94.9 m 2 /g); and then it was used to prepare the paste for the porous layer of DSSCs. The compact layer was prepared by the diluted sol through the layer-by-layer (LBL) self assembly technique to control its thickness. The compact films derived from LBL self assembly method not only prevented the charge recombination at the conductor substrate/electrolyte interface but also improved the adhesion between the porous layer and the conductive layer on the substrate, which increased the number of the effective electron pathways with the short distance of the porous layer and consequently resulted in a better electrical contact. The photoelectron conversion efficiency of the DSSCs with the LBL films had increased apparently. In particular, a 12-layer TiO 2 /PSS LBL film of the DSSC led to a 24.5% increase in the photoelectron conversion efficiency from 5.93 to 7.38%.
研究领域:
材料科学
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能源技术
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产品关联
DOI
高影响因子
Nano Energy
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2020
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IF 16.602
Qiyao Guo,Jihuai Wu,Yuqian Yang,Xuping Liu,Weihai Sun,Yuelin Wei,Zhang Lan,Jianming Lin,Miaoliang Huang,Hongwei Chen,Yunfang Huang
Metal amine halide perovskite solar cells (PSCs), as a promising next generation photovoltaic device , have undergone an unexpected swift growth in the past decade. However, the practical application of PSCs is still facing the challenge of improving efficiency and stability, and the interfacial defects at mesoporous scaffolds is the crucial bottleneck need to be solved. Here, to heal defects and enhance performance, we implement four advantageous designs, i.e. low-temperature processing, rare-earth ion doping, brookite TiO 2 scaffolds, and SnO 2 blocking layer. As a result, the binder-free and sinter-free processing generates a single crystalline phase , evenly distributed, mesoporous Sc 3+ doped brookite TiO 2 scaffold, which induces a uniform coverage, void-less and high-quality perovskite layer. The favorable energy level alignment, diminished defects and carrier recombination improve the performance of the device. Consequently, the PSC based on Sc 3+ tailored brookite TiO 2 scaffold achieves a power conversion efficiency of 21.75% with hysteresis-free and excellent UV stability.
研究领域:
材料科学
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能源技术
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光伏器件
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DOI
高影响因子
ACS Catalysis
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2019
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IF 12.221
Xiaoqiang Zhang,Peifang Yan,Bin Zhao,Kairui Liu,Mayfair C. Kung,Harold H. Kung,Shanyong Chen,Z. Conrad Zhang
The catalytic properties of physical mixtures of Ni particles (100–200 nm) with nanoparticles of anatase TiO2 (TiO2-A), ZrO2, Al2O3, rutile TiO2 (TiO2-R), and CeO2 were investigated for the hydrodeoxygenation (HDO) of guaiacol. High selectivities to phenolics were obtained only for Ni mixed with anatase TiO2 (Ni and TiO2-A), while saturated hydrocarbons were the main products for the mixtures with other supports. By thermal treatment in hydrogen gas only at 300 °C or higher and subsequently separating the large Ni particles from the TiO2-A particles with a magnet, it was further discovered that there was migration of TiO2 from TiO2-A onto the large Ni particles, resulting in an amorphous TiO2 overlayer on the Ni particles as evidenced by high-resolution TEM, and vice versa, migration of Ni onto TiO2-A. The TiO2 overlayer rendered the Ni particles completely inactive as a hydrogenation/hydrodeoxygenation catalyst. Conversely, the small amounts of Ni (<1.5 wt %) migrated onto TiO2-A formed highly dispersed Ni, undetectable by high-resolution TEM (<2 nm), that were remarkably highly active for HDO of guaiacol, producing selectively phenolics. Such highly selective HDO catalysts could also be formed by incipient wetness impregnation of Ni in loadings above 2 wt % onto the TiO2-A, but it was essential to pretreat the sample in H2 at 300 °C or higher. Pretreatment in H2 at 200 °C generated catalysts that produced saturated ring products. The activity of the impregnated catalysts, as measured by guaiacol conversion, increased linearly with Ni loading below 0.5 wt %. The activity continued to increase with Ni loading but more slowly up to 2 wt %, beyond which there was little further change. The results suggested that two types of Ni species existed on the TiO2-A surface. One type consisted of a cluster of Ni atoms that were dominant on larger Ni particles that were active in aromatic ring hydrogenation and hydrodeoxygenation. They were readily covered by reducible TiO2-A at 300 °C or higher due to the traditional strong metal support interaction (SMSI) effect and became inactive. Another type was clusters of a very small number of Ni atoms, perhaps one atom, that were present as highly dispersed Ni clusters interacting strongly with the defect sites of TiO2-A. The strong interaction of this type of Ni with the TiO2 defect deterred TiOx migration allowing surface exposed Ni atoms to catalyze the HDO of guaiacol with very high selectivities that were not characteristic of typical Ni particles.
研究领域:
催化化学
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能源化学
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材料科学
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产品关联
DOI
高影响因子
Catalysts
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2023
·Vol. 13
·期 6
·995
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IF 3.9
Haisheng Huang,Juan Wang,Qi Kong,Yao Xu,Zhishun Wei,Ying Chang
Anatase TiO2hierarchically structured microspheres with co-exposed {001}/{101} facets were prepared by a facile one-pot hydrothermal method. The influences of reaction temperature on the morphology and crystallization of microspheres were investigated systematically. The obtained microspheres possessed better morphology and crystallization when the reaction temperature was 160 °C. Different noble metals (Au, Ag, Cu, Pt, Pd) were used for the microspheres modification, and the experimental results exhibited that the photocatalytic activities of the noble metal modified microspheres were enhanced obviously, especially for the Pt-modified sample (TPt), which showed the highest photocatalytic activity in degradation of tetracycline hydrochloride (the TPt sample showed the largest improvement, i.e., the activity reached 1.47 times higher than that of the bare sample) and hydrogen production (the largest improvement was also observed for the TPt sample, i.e., the activity was more than 30 times as the bare sample, reaching more than 300 μmol·g−1·h−1). Finally, a photocatalytic reaction mechanism involving the synergy of co-exposed {001}/{101} crystal facets with noble metals was proposed according to the as-obtained experimental results.Keywords:titanium oxide;microsphere;hierarchical structure;noble metal;photocatalysis
研究领域:
材料科学
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化学工程
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环境科学
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DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
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2019
·Vol. 33
·期 11
·e5230
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IF 3.259
Xian Zhang,Chang Liu,Min Wang,Xiao Sun,Xiao Yu Sun,Ni Xian Qian,Rui Rao,Yong Qing Ma
Anatase titania (TiO 2 ) nanoparticles were synthesized via a self-developed ethanol vapor-thermal method at 240°C (T240) and 250°C (T250), i.e. at temperatures lower and higher, respectively, than the supercritical temperature (243.5°C, 7.0 MPa) of ethanol. Compared to T240, T250 exhibited a higher ratio of exposed (001) facets, oxygen vacancies, and concomitant TiO x . The specific surface area of T250 was 119.0 m 2 g −1 , smaller than that of T240 (144.2 m 2 g −1 ). During the degradation of methylene blue, T250 exhibited a high apparent rate constant ( K app ) of 14.5 × 10 −2 min −1 , which was 6.3 times larger than that for T240. Furthermore, compared to T240, T250 exhibited better performance toward degradation of phenol. Results of electron spin resonance spectroscopy and photoluminescence indicated that the photogenerated electron–hole pairs possessed higher separation efficiency for T250 than for T240. In summary, the excellent photocatalytic performance of T250 originates from the higher ratios of exposed (001) facets, oxygen vacancies or TiO x , C═O groups adsorbed at the surface of particles, and higher separation efficiency of photogenerated electron–hole pairs. By employing this self-developed vapor-thermal method, a variety of catalysts and their composites can be synthesized, which may exhibit novel morphological characteristics and properties as well as excellent photocatalytic performance.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Journal of Physical Chemistry C
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2015
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IF 4.772
Linlin Hao,Xianqiang Xiong,Yiming Xu
The development of a highly active TiO2 photocatalyst for energy and environmental use is a great challenge. In this work, we report that the addition of sodium borate to an aqueous suspension of anatase TiO2 at neutral pH can result in a significant enhancement in the rate of phenol degradation. Similar results were also observed from 2,4-dichlorophenol degradation, spin-trapped OH radical formation, H2O2 decomposition, and chromate reduction in the presence of phenol. This borate-induced rate increase for phenol degradation was determined not only by the amount of borate adsorption but also by the structure of borate species (pH effect). A (photo)electrochemical measurement with the TiO2 film revealed that upon addition of borate, the hole consumption by phenol and the electron consumption by O2 were accelerated and decelerated, respectively. Moreover, the flat band potential of TiO2 was negatively shifted by 81 mV. Since the hole oxidation of water to O2 remained unchanged, it is proposed that a borate radical is produced, followed by regeneration through phenol oxidation. This borate-mediated hole transfer would promote the electron transfer to O2 and consequently improve the efficiency of the charge separation for phenol degradation at interfaces.
研究领域:
环境科学
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材料科学
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化学
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光化学
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产品关联
DOI
高影响因子
Coatings
·
2022
·Vol. 12
·期 1
·64
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IF 3.236
Yuanzhi Min,Gao Song,Ling Zhou,Xinyue Wang,Pingying Liu,Jumei Li
Nanostructured noble metal-semiconductor materials have been attracting increasing attention because of their broad application in the field of environmental remediation, sensing and photocatalysis. In this study, a facile approach for fabricating silver@mesoporousanataseTiO2(Ag@mTiO2) core-shell nanoparticles employing sol-gel and hydrothermal reaction is demonstrated. The Ag@mTiO2nanoparticles display excellent surface-enhanced Raman scattering (SERS) sensitivity and they can detect the methylene blue (MB) molecules with the concentration of as low as 10−8M. They also exhibit outstanding photocatalytic activity compared with mTiO2, due to the efficient separation and recombination restrain of electron–hole pairs under ultraviolet light. The Ag@mTiO2nanoparticles also present good stability and they can achieve recyclable photocatalytic degradation experiments for five times without loss of activity. Subsequently, the nanoparticles with dual functions were successfully used to in situ monitor the photodegradation process of MB aqueous solution. These results, demonstrating the multifunctional Ag@mTiO2nanoparticles, hold promising applications for simultaneous SERS analysis and the removal of dye pollutants in environmental field.Keywords:photocatalytic degradation;surface-enhanced Raman scattering;TiO2;Ag nanoparticle;core-shell
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
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2015
·Vol. 3
·期 12
·6455-6463
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IF 7.443
Kunlei Zhu,Xiaoyan Liu,Jiangyong Du,Jianhua Tian,Yun Wang,Shengzhong Liu,Zhongqiang Shan
There are few reports on mesoporous anatase TiO2 nanosheets being synthesized without additives and ex situ templates under mild conditions. In this study, mesoporous single-grain layer anatase (MSGLA) TiO2 nanosheets were first synthesized in situ without additives in a new methanol–tetrabutyl titanate (TBT) system on a large scale using a simple and easily reproducible method. The formation mechanism of the MSGLA TiO2 nanosheets was investigated in detail. The results suggest that MSGLA TiO2 nanosheets can be obtained after a simple thermal treatment of amorphous TiO2 sheets that are converted in situ from the precursor Ti(OC4H9)4−n(OCH3)n (1 ≤ n ≤ 4) (TBM), which is gained easily via the transesterification reactions of TBT and anhydrous methanol at room temperature. Moreover, the MSGLA TiO2 nanosheets were applied successfully as anode materials for Li-ion batteries (LIB) and exhibited a discharge capacity of ∼73 mA h g−1 with obvious voltage plateaus over 4000 cycles (a test time of ∼50 days) at 5 C (1 C = 170 mA g−1) and Coulombic efficiencies of each cycle approaching 100%, highlighting them as promising materials for long-term LIB.
研究领域:
材料科学
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纳米技术
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能源存储
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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）