PROPELLANTS EXPLOSIVES PYROTECHNICS
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2016
·Vol. 41
·期 5
·798-805
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IF 1.578
Na Sun,Cuihua Tian,Zhenggang Xiao
In order to tailor the surface properties of propellants to meet the requirements of progressive burning and anti-erosion performance of propellant for high loading density tank guns, the surface migration and enrichment effects of fluorinated TiO 2 nanocomposite additives with low surface energy toward the air/solid interface of propellants were investigated. Fluorinated TiO 2 nanocomposites were prepared by emulsion polymerization and characterized by FT-IR spectroscopy, TEM, and TGA to obtain the information of chemical groups, morphology, and thermal stability. The propellant samples containing the fluorinated TiO 2 nanocomposite additives were manufactured by an extrusion process. The migration effect of the fluorinated TiO 2 nanocomposite additives was observed by SEM and X-ray energy dispersive analysis. The influence factors on the migration and enrichment properties of fluorinated TiO 2 nanocomposite additives in propellants were discussed. The results showed that there exists a gradient distribution of fluorine element in the additive modified propellants, indicating a significant surface enrichment of fluorinated groups inside the propellants. The composition of propellants and the chain structure of fluoropolymer also have a significant influence on the migration and enrichment properties of fluorinated TiO 2 nanocomposite additives in propellants. This study can bring forward the research of smart construction of slowing burning and anti-wear layers in the propellants.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Materials Advances
·
2022
·Vol. 3
·期 4
·2185-2190
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IF 0
Ping Li,Mengyou Gao,Lei Sun,Huizhong Xu,Xiaochen Dong,Jianjian Lin
Coating a few layers of MoS2 nanosheets on a substrate is an effective approach to enhance catalytic activity for photocatalytic degradation. Herein, we fabricated heterostructured TiO2/MoS2 (H-TiO2/MoS2) with high structural stability via a simple two-step solvothermal approach. H-TiO2/MoS2 was composed of TiO2 as a hard core and MoS2 nanosheets as a shell, which could increase the electron transfer rate between TiO2 and MoS2 and enable active edge sites of MoS2 to be maximally exposed. Besides, H-TiO2/MoS2 indicated enhanced light absorption in the UV to Vis range when compared to TiO2 nanoparticles, and slightly lower than that of MoS2. This is beneficial for the enhancement of the photocatalytic degradation performance. Therefore, H-TiO2/MoS2 displayed a strong adsorption ability toward organic dyes and showed excellent performance in the photocatalytic degradation of rhodamine B with the concentration decreased by 99.4% due to the synergistically stimulative effect. The work will enlighten the development of highly efficient molybdenum sulfide-based heterostructured photocatalysts.
研究领域:
材料科学
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环境科学
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化学
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产品关联
DOI
CHEMOSPHERE
·
2022
·
IF 8.943
Yunjin Zhong,Haixiang Chen,Xiufang Chen,Bingying Zhang,Wenxing Chen,Wangyang Lu
As some of the most promising alternatives to traditional non-degradable materials, photodegradable materials have advantages of environmental benignity and rapid degradation under simple conditions. In this work, nontoxic TiO 2 and cost-effective g-C 3 N 4 have been compounded in a weight of 9:1 to form a photocatalytic additive with high activity. A 25 wt% loading of this photocatalytic additive has been incorporated into the polyacrylonitrile (PAN) by centrifugal electrospinning to prepare an abiotic degradable PAN material. Our results showed that the PAN chain could be almost fully degraded within 90 h in an aqueous medium under simulated sunlight in the absence of microorganisms . Product analysis implied that degradation of the PAN chain mainly involved the breaking of –CN and C–C bonds by radicals, followed by oxidation of terminal groups to carboxyl and gradual mineralization to CO 2 and H 2 O. This design strategy may provide new insight for the production and degradation mechanism of photodegradable polymer.
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
RSC Advances
·
2018
·Vol. 8
·期 25
·14056-14063
·
IF 2.936
Juanjuan Ma,Chaocun Zhou,Jinlin Long,Zhengxin Ding,Rusheng Yuan,Chao Xu
Graphene-based cocatalysts can improve the photocatalytic properties of semiconductors, but sometimes, they also function as barrier-like materials, influencing the photoactivity of composites. However, in a multi-cocatalyst system, less attention is paid to these negative effects of graphene on the performance of other cocatalysts. In this study, by adjusting the loading sequence of graphene and Ag cocatalyst on the surface of TiO2 spheres, the barrier effect of graphene sheets on Ag nanoparticles could be controlled effectively. As a result, these ternary composites with almost no Ag nanoparticles wrapped by graphene possessed improved properties for the photocatalytic reduction of nitro-aromatics as compared to those with some Ag nanoparticles covered by graphene. Furthermore, this phenomenon of barrier effect caused by graphene could be found in the control reaction with metal silver as the main catalyst; this indicated that by avoiding the possible negative influence of graphene on other cocatalysts, the properties of composites with graphene-containing multi cocatalysts could be further improved.
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
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Zongxiong Xu,Hao Fu,Tian Wen,Lei Zhang,Jian Zhang
Titanium-oxo clusters (TOCs) are important model complexes and potential precise single-source precursors of TiO 2 materials. We report here a series of TiO 2 samples derived from TOCs with the same wheel-like Ti 8 O 8 clustercore but different stabilizing ligands. Our results demonstrate that the ligands on TOCs not only influence the phase-transition during themolysis, but more importantly tune the photocatalytic H 2 evolution activities of the obtained TiO 2 materials. Through 500 °C calcination , the nanosized Ti 8 O 8 cluster stabilized by organic benzoate ligands gives rise to a TiO 2 sample with H 2 production rate of 611 μ mol/h/g. When the stabilizing ligands are changed to inorganic SO 4 2− , a significant improvement of H 2 evolution activity has been achieved, resulting in a 7-times higher value of 4527 μ mol/h/g. This work provides a new strategy to produce TiO 2 with enhanced and tunable photocatalytic activities from titanium-oxo cluster precursors.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2022
·
IF 3.806
Xiaoyi Zhang,Guoliang Lin,Shenglan Ma,Mingyi Liu,Wanxi Jiang,Chen Wu
This article has been retracted: please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy ). This article has been retracted at the request of the Corresponding Authors and Editor-in-Chief. One of the corresponding authors, Xiaoyi Zhang, notified the journal of several issues relating to the article and requested its retraction. These issues have been detailed below: - The experiments were not performed as reported in the article. Specifically, the coating was applied to a wood surface, rather than the reported concrete surface. When subsequent experiments were conducted using concrete, the experimental data were not reproducible. - Some of the authors informed the journal that they were not aware of the content of the manuscript, nor of their authorship. - In addition, according to Dr. Zhang: “…the pictures and data in the paper are used incorrectly, resulting in unreliable experimental results”. These issues represent a clear violation of our publishing policies, and publishing ethics standards. The Editor-in-Chief has assessed the case and decided to retract the article. The corresponding authors agreed to the retraction.
研究领域:
材料科学
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土木工程
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化学
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DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 19
·3444
·
IF 5.719
Fei Han,Sai Ma,Dong Li,Md Mofasserul Alam,Zeheng Yang
An Sb2S3-sensitized TiO2(Sb2S3/TiO2) photo-anode (PA) exhibiting a high photo-electrochemical (PEC) performance in water oxidation has been successfully prepared by a simple chemical bath deposition (CBD) technique. Herein, the Raman spectra and XPS spectrum of Sb2S3/TiO2confirmed the formation of Sb2S3on the TiO2coatings. The Sb2S3/TiO2photo-anode significantly shifted the absorption edge from 395 nm (3.10 eV) to 650 nm (1.90 eV). Furthermore, the Sb2S3/TiO2photo-anode generated a photo-anodic current under visible light irradiation below 650 nm due to the photo-electrochemical action compared with the TiO2photo-anode at 390 nm. The incident photon-to-current conversion efficiency (IPCE = 7.7%) at 400 nm and −0.3 V vs. Ag/AgCl was 37 times higher than that (0.21%) of the TiO2photo-anodes due to the low recombination rate and acceleration of the carriers of Sb2S3/TiO2. Moreover, the photo-anodic current and photostability of the Sb2S3/TiO2photo-anodes improved via adding the Co2+ions to the electrolyte solution during photo-electrocatalysis.Keywords:Sb2S3/TiO2;photo-anode;long wavelength;photo-electrochemical;water oxidation
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Wei Chen,Jinyan Xiong,Zhipan Wen,Rong Chen,Gang Cheng
Photocatalytic CO 2 reduction offers a potential to produce clean and renewable fuels as well as reduce massive emissions of CO 2 by utilizing solar energy. The inhibited charge recombination and fertile surface reactive sites play vital roles in determining the photocatalytic performance and products selectivity in CO 2 reduction reaction. Herein, the Ag/TiO 2-x hybrid by synchronistic introduction of oxygen vacancy and Ag nanoparticles into SiO 2 spheres-templated potholed TiO 2 assembly with nanoparticles is constructed for photocatalytic CO 2 conversion. The Schottky junction between oxygen vacancy TiO 2-x and Ag particles provides synergistic enhancement of solar light utilization, photo-induced charge separation and migration process, which is of significance in the promoted CO 2 photo-conversion. Indeed, the CH 4 yield of oxygen vacancy TiO 2-x (1.56 μmol/g/h) is more than 3 times as high as the TiO 2 (0.47 μmol/g/h), while the as-synthesized Ag/TiO 2-x hybrids show an enhancement of photocatalytic CO 2 reduction into CH 4 and CO. Among them, the Ag/TiO 2-x -10% hybrid has the best photocatalytic performance, and it shows significantly superior CH 4 (8.61 μmol/g/h) and CO (2.27 μmol/g/h) yields to that of pure TiO 2-x and TiO 2 .
研究领域:
材料科学
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环境科学
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能源科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Yingguang Zhang,Muyan Wu,Y.H. Kwok,Yifei Wang,Wei Zhao,Xiaolong Zhao,Haibao Huang,Dennis Y.C. Leung
A series of TiO 2 /MnO 2 heterojunction catalysts were fabricated through an in-situ hydrothermal method, and for the first time, catalysts with this heterojunction structure were used for VUV-PCO toluene degradation. After the MnO 2 coating, the TiO 2 /MnO 2 catalysts performed excellently for both VOCs degradation and residual ozone decomposition with removal efficiency reaching 96.0% and 99.9%, respectively. The enhanced photocatalytic activity towards toluene degradation could be attributed to the heterojunction structure of TiO 2 /MnO 2 , which provides excellent contact between MnO 2 and TiO 2 , and suppresses the recombination of photogenerated electron-hole pairs. Moreover, benefiting from the MnO 2 , the ozone generated in the system could be efficiently utilized and eliminated during the VUV-PCO process. The photocatalytic mechanism of TiO 2 /MnO 2 for the toluene degradation and ozone decomposition was proposed.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
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2021
·Vol. 54
·期 37
·375101
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IF 3.207
Min Yang,Yujia Yan,Enzhou Liu,Jun Fan,Xiaoyun Hu
As a typical sulfide bimetallic semiconductor material, AgInS2 has been widely studied for its excellent photoelectrochemical properties. However, due to the large lattice mismatch, it is difficult to obtain AgInS2 single phase nanocrystals by conventional reaction. Therefore, the ligand and pH were selected and adjusted for the preparation of AgInS2 single phase nanocrystals. Adding organic molecules containing sulfhydryl groups as ligands could combine with metal ions to form covalent bonds, while OH− could react with transition metal ions to form soluble metal hydroxides, which could protect metal ions from direct reaction with S2−. With the help of x-ray powder diffraction, AgInS2 single phase nanocrystals were successfully prepared by hydrothermal reaction at 180 °C with L-cysteine (L-Cys) or glutathione as the ligand in an alkaline environment. Finally, it was determined that the AgInS2 single phase nanocrystals obtained when the ligand was L-Cys and the reaction time was locked to 24 h had high catalytic activity as determined by a rhodamine B (RhB) removal experiment. In addition, AgInS2/TiO2 (AIS-TO) heterojunction photocatalysts were prepared by an in-situ hydrothermal method to improve the photocatalytic activity of TiO2. Among them, the 5% AIS-TO sample showed the highest catalytic activity, and the degradation rate of RhB was 2.4 times that of TiO2. It was also proved that electrons were transported by a Z-type mechanism in the AIS-TO heterojunction photocatalytic system. This work would provide a feasible scheme for the preparation of more sulfide bimetallic semiconductor single phase nanocrystals.
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
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Di Li,Qin Li,Yimeng Zhou,Qiong Zhang,Qianjin Ye,Ran Yang,Deli Jiang
Steering selectivity in photocatalytic conversion of CO2, especially toward deep reduction products, is vital to energy and environmental goals yet remains a great challenge. In this work, we demonstrate a facet-dependent photocatalytic selective reduction of CO2 to CH4 in Cu-doped TiO2 catalysts exposed with different facets synthesized by a topological transformation from MIL-125 (Ti) precursors. The optimized round cake-like Cu/TiO2 photocatalyst mainly exposed with the (001) facet exhibited a high photocatalytic CO2 reduction performance with a CH4 yield of 40.36 μmol g–1 h–1 with a selectivity of 94.1%, which are significantly higher than those of TiO2 (001) (4.70 μmol g–1 h–1 and 52.6%, respectively), Cu/TiO2 (001 + 101) (18.95 μmol g–1 h–1 and 69.6%, respectively), and Cu/TiO2 (101) (14.73 μmol g–1 h–1 and 78.9%, respectively). The results of experimental and theoretical calculations demonstrate that the Cu doping dominating the promoted separation and migration efficiencies of photogenerated charges and the preferential adsorption on (001) facets synergistically contribute to the selective reduction of CO2 to CH4. This work highlights the significance of synergy between facet engineering and ion doping in the design of high-performance photocatalysts with respect to selective reduction of CO2 to multielectron products.
研究领域:
材料科学
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环境科学
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能源科学
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Gang Liu,Sheng Xu,Wenting Li,Zhenxi Wang,Jinlong Cui
In order to expand the photoresponsive spectrum of TiO 2 and improve its catalytic activity under visible light, the hollow urchin-like composites of TiO 2 @g-C 3 N 4 /GQDs (TCN/GQDs) with a core-shell structure heterojunction was synthesized through a hydrothermal method and calcination. Potassium titanium oxalate, melamine, and citric acid were utilized as the raw materials for this synthesis process. The TCN/GQDs composites were subjected to a range of analyses to examine their microstructure and photoelectric properties. The findings indicated that the synthesized composites effectively enhanced the absorption spectrum of TiO 2 in the visible light range by creating the stable heterojunctions among TiO 2 , g-C 3 N 4 and GQDs. Additionally, the ability of these composites to degrade toxic organic pollutants under visible light was studied by using several different organic dyes and antibiotics. The results demonstrated that the TCN/GQDs composites exhibited efficient visible light catalytic degradation capability on organic pollutants, and the degradation efficiency could approach to 100 % under visible light in a short time. Furthermore, the photocatalyst exhibited hardly change of degradation efficiency towards organic pollutants even after 5 cycles of testing, suggesting its commendable performance in visible light catalysis and potential for repeated utilization.
研究领域:
材料科学
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环境科学
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光催化
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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）