JOURNAL OF ALLOYS AND COMPOUNDS
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2012
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IF 2.289
Y.T. Zheng,Z.L. Zhang,Y.L. Mao
A composite of SrTiO 3 /TiO 2 was successfully prepared using TiO 2 (Degussa P25) and SrTiO 3 powders as starting materials. The composite was characterized by X-ray diffraction (XRD), UV–vis absorption spectrum, scanning electron microscope (SEM), and surface photovoltage spectroscopy (SPS). The SrTiO 3 /TiO 2 composite presents an enhanced photovoltaic response compared with pure TiO 2 and SrTiO 3 . The enhancement was explained by investigating the energy levels of TiO 2 and SrTiO 3 , and the photoluminescence (PL) spectra of TiO 2 , SrTiO 3 and SrTiO 3 /TiO 2 . The analysis of energy levels shows that those of TiO 2 and SrTiO 3 are matching, which improves the separation efficiency of photogenerated carriers. The PL spectra indicate that the formation of SrTiO 3 /TiO 2 composite decreases the recombination rate of photogenerated carriers. Thus the photovoltaic response enhancement is mainly resulting from the improved separation efficiency and decreased recombination rate of photogenerated carriers for SrTiO 3 /TiO 2 composite.
研究领域:
材料科学
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光电化学
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产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 23
·5824
·
IF 3.1
Guoyu Zhang,Lu Li,Yanxin Nan,Peng Li,Tao Deng,Zhipeng Lei,Yuanyuan Li,Jianhua Zhang
In this work, the effects of different sintering temperatures and TiO2concentrations on the dielectric properties of ZrO2and Nb2O5pre-doped CaCu3Ti4O12(CCTO) ceramics were investigated. These doped ceramics were sintered at temperatures of 1020, 1030, and 1040 °C, exhibiting the lowest dielectric loss of 0.01, which consistently remained below 0.03 across a wide frequency range from 10 to 105Hz. Simultaneously, they maintained a high dielectric constant of more than 3000 and remarkably met the requirements for an X8P capacitor (Δε′ ≤ ±10% at temperature range from −55 to 150 °C). It was clarified that TiO2doping increased grain boundary resistance, leading to the reduced dielectric loss, and elevated the grain boundary activation energy, thereby enhancing the temperature stability. The TiO2-doped CCTO-based ceramics also demonstrated reduced sensitivity to variations in sintering temperature, highlighting their excellent manufacturability. This characteristic holds great promise for the fabrication of CCTO-based ceramics, which usually exhibit poor repetitiveness.
研究领域:
材料科学
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电子工程
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产品关联
DOI
PubMed
高影响因子
International Journal of Environmental Research and Public Health
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2022
·Vol. 19
·期 14
·8683
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IF 4.614
Xiang Guo,Lei Rao,Zhenyu Shi
Adsorption can quickly remove pollutants in water, while photocatalysis can effectively decompose organic matter. B-TiO2/g-C3N4ternary composite photocatalytic materials were prepared by molten method, and their adsorption–degradation capability under visible light conditions was discussed. The morphology of the B-TiO2/g-C3N4materials was inspected by SEM, TEM, BET, and EDS, and the results showed that close interfacial connections between TiO2and g-C3N4, which are favorable for charge transfer between these two semiconductors, formed heterojunctions with suitable band structure which was contributed by the molten B2O3. Meanwhile, the molten B2O3effectively increased the specific surface area of TiO2/C3N4materials, thereby increasing the active sites and reducing the recombination of photogenerated electron–hole pairs and improving the photocatalytic degradation abilities of TiO2and g-C3N4. Elsewhere, the crystal structure analysis (XRD, XPS, FTIR) results indicated that the polar -B=O bond formed a new structure with TiO2and g-C3N4, which is not only beneficial for inhibiting the recombination of electron holes but also improving the photocatalytic activity. By removal experiment, the adsorption and degradation performances of B-TiO2/g-C3N4composite material were found to be 8.5 times and 3.4 times higher than that of g-C3N4. Above all, this study prepared a material for removing water pollutants with high efficiency and provides theoretical support and experimental basis for the research on the synergistic removal of pollutants by adsorption and photocatalysis.Keywords:adsorption;degradation;B2O3;TiO2/C3N4;molten
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
iScience
·
2024
·
IF 4.6
Hong Qian,Binxia Yuan,Yuhao Liu,Rui Zhu,Weiling Luan,Chengxi Zhang
In this study, a method was developed to create oxygen vacancies in Cu 2 O/TiO 2 heterojunctions. By varying the amounts of ethylenediaminetetraacetic acid (EDTA), sodium citrate, and copper acetate, Cu 2 O/TiO 2 with different Cu ratios were synthesized. Tests on CO 2 photocatalytic reduction revealed that Cu 2 O/TiO 2 ’s performance is influenced by Cu content. The ideal Cu mass fraction in Cu 2 O/TiO 2 , determined by inductively coupled plasma (ICP), is between 0.075% and 0.55%, with the highest CO yield being 10.22 μmol g −1 h −1 , significantly surpassing pure TiO 2 . High-resolution transmission electron microscopy and electron paramagnetic resonance studies showed optimal oxygen vacancy in the most effective heterojunction. Density functional theory (DFT) calculations indicated a 0.088 eV lower energy barrier for ∗CO 2 to ∗COOH conversion in Cu 2 O/TiO 2 with oxygen vacancy compared to TiO 2 , suggesting that oxygen vacancies enhance photocatalytic activity.
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
IONICS
·
2012
·Vol. 19
·期 3
·529-534
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IF 1.288
Wang Wei,Wang Hui,Key Julian,Linkov Vladimir,Ji Shan,Wang Rongfang
To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO 2 -promoted PtRu/C catalysts were prepared by directly mixing TiO 2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO 2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electrooxidation. The value of the apparent activation energy ( E
a ) for TiO 2 -PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO 2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO 2 nanoparticles into PtRu/C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2019
·
IF 3.355
Zhendong Liu,Zhen Ma
TiO 2 has been regarded as an efficient benchmark photocatalyst that can work under ultraviolet light. However, further modification of TiO 2 for achieving even higher photocatalytic activities is necessary for practical applications and for enriching the family of TiO 2 -based photocatalysts. Herein, a novel Ag-SrTiO 3 /TiO 2 photocatalyst was prepared by hydrothermally treating TiO 2 nanosheets in an aqueous Sr(OH) 2 solution (to form SrTiO 3 nanocubes supported on TiO 2 nanosheets) followed by depositing Ag nanoparticles via photoreduction in the presence of an aqueous AgNO 3 solution. In this case, Ag nanoparticles were found to be deposited on both SrTiO 3 and TiO 2 surfaces. The resulting Ag-SrTiO 3 /TiO 2 was found to be more active than reference catalysts such as TiO 2 , SrTiO 3 /TiO 2 , Ag/TiO 2 , and Ag/SrTiO 3 in photocatalytic degradation of rhodamine B (RhB) and ciprofloxacin hydrochloride (CIP) under simulated sun light. Relevant catalysts were characterized systematically, and possible reasons for the enhanced activity of Ag-SrTiO 3 /TiO 2 was explained.
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
APPLIED CLAY SCIENCE
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2017
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IF 3.101
Sen Lin,Shiyong Sun,Kexuan Shen,Daoyong Tan,Hongping Zhang,Faqin Dong,Xiaoxin Fu
Photocatalytic microcompartments have attracted increasing interests in the field of photocatalytic degradation . This work focused on the construction and characterization of a novel photocatalytic microsystem comprising polydopamine-modified TiO 2 nanoparticles (NPs) dispersed in clay-based colloidosomes, utilizing partially hydrophobic montmorillonite particles as building blocks for colloidosome membrane assembly. Assessment of photocatalytic activity was performed by photocatalytic degradation of methylene blue and rhodamine B, with the small molecule dyes decomposing within the compartmentalized microsystems. Encapsulation of TiO 2 NPs within the clay colloidosomes enhanced the efficiency of photocatalytic degradation. The results showed a selective degradation of methylene blue in the presence of rhodamine B, with associated λ MB /λ RhB of 2.04. The present study indicates that photocatalytic semiconductor NPs encapsulated in clay colloidosomes form a promising microsystem with great potential for application in environmental remediation.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 17
·3019
·
IF 5.719
Jiaqi Chen,Jian Gao,Xiaoyang Liu,Pan Wang,Xue Yu,Feng Zhao,Yan Sun,Wei Feng,Qingyuan Wang
Degradation of organic pollutants, especially organic dyes and antibiotics, by semiconductor photocatalysts is an efficient strategy for wastewater treatment. TiO2nanomaterials are considered to be promising photocatalysts due to their high chemical stability, high efficiency and availability. Anatase TiO2generally has superior photocatalytic activity to the rutile phase. However, the anatase phase can be irreversibly transformed to rutile phase when calcined at an elevated temperature. Methods to improve the stability of anatase are especially important for the TiO2gas sensors working at high temperatures. The addition of strong acids can effectively suppress this transformation process. However, these strong acids are relatively expensive, corrosive and environmentally unfriendly. Herein, oxalic acid (OA) as a natural acid was used to control the hydrolysis process of tetrabutyl titanate (TBOT), leading to controllable crystalline phase transformation and reduced crystalline size of TiO2on the nanoscale. What is more, the photocatalytic degradation performances were enhanced continuously when the molar ratio of OA to TBOT increased. The degradation reaction rate constants of CT650-R25 were about 10 times that of CT650-R0. The mechanism study shows that the enhanced photocatalytic activity can be attributed to the improved dispersibility, increased specific surface area and reduced recombination rates of photo-induced charge carriers and decreased energy bands as the concentration of OA increased. Thus, this work provides a simple, mild and effective method for controlling the crystalline forms of nano-TiO2with enhanced photocatalytic performance towards waste water treatment.Keywords:TiO2;photocatalyst;inhibitor;phase transformation
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
Journal of Environmental Sciences
·
2024
·
IF 5.9
Jiahui Liu,Fangyuan Dong,Yaqi Huang,Yanghe Fu,Xinqing Lu,Rui Ma,Fumin Zhang,Shuhua Wang,Weidong Zhu
Reducing the cost of RuO 2 /TiO 2 catalysts is still one of the urgent challenges in catalytic HCl oxidation. In the present work, a Ce-doped TiO 2 supported RuO 2 catalyst with a low Ru loading was developed, showing a high activity in the catalytic oxidation of HCl to Cl 2 . The results on some extensive characterizations of both Ce-doped TiO 2 carriers and their supported RuO 2 catalysts show that the doping of Ce into TiO 2 can effectively change the lattice parameters of TiO 2 to improve the dispersion of the active RuO 2 species on the carrier, which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions. This work provides some scientific basis and technical support for chlorine recycling.
研究领域:
化学工程
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催化科学
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产品关联
DOI
PubMed
高影响因子
VACUUM
·
2024
·
IF 3.8
Xiaoying Yu,Chunhong Gao,Jinjia Liu,Jiang Wang,Meilin Jia,Gala Sa,Aiju Xu
Photocatalytic technology has good stability and ecological friendliness which is used to treat organic pollutants in wastewater. In this paper, TiO 2 , 1.5%V–TiO 2 and N, V co-doped TiO 2 were synthesized by hydrothermal method for photocatalytic degradation of tetracycline. Meanwhile, XRD , HRTEM , SEM, FT-IR, XPS, UV–Vis DRS , PL and electrochemistry tests were used to characterize the catalysts. The results showed that the appropriate amount of N, V co-doped can cause structural changes of TiO 2 . The co-doped of N and V enhanced the photocurrent response of TiO 2 , increased the specific surface area, reduced the band gap, and improved the efficiency of photodegradation of tetracycline. Accordingly, the tetracycline photocatalytic degradation path was proposed. 6%N-1.5%V–TiO 2 completely degraded tetracycline into CO 2 , H 2 O and NO 3 − . The calculation results show that an appropriate amount of N, V co-doped TiO 2 decreased bandgap, improved the optical absorption performance of TiO 2 . This work demonstrated the potential of N, V co-doped to design efficient photocatalysts .
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 8
·期 1
·334-341
·
IF 10.733
Guoqiang Zhang,Xun Yang,Chuanxin He,Peixin Zhang,Hongwei Mi
Photocatalytic systems capable of precisely regulating oxygen vacancy (OV) concentrations, which could help illuminate the effects of the OV concentration on N2 fixation activity, are still scarce. Here, we demonstrate that excessive OVs in TiO2, while increasing the adsorption activation capacity of N2 molecules, exhibit disappointing activity due to a decrease in charge separation efficiency. With optimized OV concentration, TiO2 can increase the charge separation efficiency 3-fold and show significant activation towards N2 molecules. The normalized N2 photofixation rate is 324.86 μmol h−1 g−1 (full spectrum) and the corresponding apparent quantum yield (AQY) under 365 nm illumination reaches 1.1%, which are relatively high levels compared to reports in the literature. The origin of this excellent activity is clearly attributable to the OV defect structures, which coordinate the charge separation efficiency and the dissociative adsorption capacity of N2. This work establishes the relationship between OV concentration and activity, and helps to construct a highly efficient nitrogen-fixing photocatalyst by optimizing the OV concentration.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
Heliyon
·
2024
·
IF 3.4
Yihang Yue,Xiaoju Yue,Xiaofeng Tang,Lin Han,Jinnong Wang,Shifeng Wang,Chun Du
The discharge of organic pollutants by the textile and dyeing industries presents an escalating threat to aquatic environments, necessitating the development of effective remediation strategies. This study introduces the utilization of graphite-like structured activated carbon (AC), derived from highland barley straw—a biomass unique to the Plateau regions of China, including Tibet, Qinghai, and Gansu—as a support material for the TiO 2 catalyst. TiO 2 /AC composites with different TiO 2 loadings were synthesized by ultrasonic impregnation. The TiO 2 /AC composites were found to be polycrystalline materials composed of anatase and rutile phases. The TiO 2 nanoparticles are well-dispersed over the surface of the AC. The photocatalytic activity of these composites was evaluated through their capacity to degrade a methylene blue (MB) solution upon irradiation. It was observed that the inclusion of TiO 2 increases the number of adsorption sites and active sites for methylene blue, with the photocatalytic activity being notably higher at a 3-wt% TiO 2 loading, achieving a remarkable 99.6 % degradation efficiency for 100 mg/L MB within 100 min. The experimental kinetic data for the photocatalytic process follow the pseudo-first-order kinetic model. Furthermore, TiO 2 /AC retains high photocatalytic activity after five reaction cycles. This research provides valuable insights into the application of biomass-derived materials for the purification of water, offering a sustainable solution to both pollution and agricultural waste challenges in Plateau areas of China.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
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