MATERIALS CHEMISTRY AND PHYSICS
·
2016
·
IF 2.101
Renping Cao,Guo Chen,Xiaoguang Yu,Pengjie Tang,Zhiyang Luo,Siling Guo,Guotai Zheng
Ca [1−3x/2] TiO 3 :xSm 3+ (0 ≤ x ≤ 5 mol%), Ca 0.955 TiO 3 :0.03Sm 3+ + 10 mol% H 3 BO 3 , Ca 0.94 TiO 3 :0.03Sm 3+ , 0.03Na + phosphors are synthesized by high temperature solid–state reaction method in air. All samples are pure phase CaTiO 3 . Two strong excitation bands within the range 400–435 nm and 455–510 nm are observed, which are nicely match with widely applied near-UV (400–430 nm) and blue (460–500 nm) LED chips. The strongest emission band peaking at ∼603 nm is assigned to the 4 G 5/2 → 6 H 7/2 transition of Sm 3+ ion. The optimal Sm 3+ doping concentration is ∼3 mol%. Fluorescent lifetimes of Ca 0.955 TiO 3 :0.03Sm 3+ phosphor with excitation 408, 467, and 481 nm are ∼0.809 m, 0.792 m, and 0.8 m, respectively. The PL intensity of Ca 0.955 TiO 3 :0.03Sm 3+ phosphor is enhanced 5–7 times after Na + ion is codoped as charge compensator and H 3 BO 3 is added as flux, and their CIE chromaticity coordinate is ∼ (0.5792, 0.4199). The experiment results are helpful to improve luminescence properties of other Sm 3+ -doped phosphors and study novel phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2018
·Vol. 71
·期 12
·965-970
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IF 1.059
Lingfeng Ruan,Rongying Jiang,Jing Liu,Song Liu
BaTiO3/TiO2 and CaTiO3/TiO2 bilayer-type photocatalyst films have been prepared and characterised by X-ray diffraction, Raman, X-ray photoelectron spectroscopy, UV-vis, and scanning electron microscopy techniques. The photodeposition of silver was done to confirm the reduction positions of the titanate/TiO2 films. Silver deposited preferentially on the side of TiO2 for BaTiO3/TiO2 whereas on the side of CaTiO3 for CaTiO3/TiO2. These results imply that the direction of photogenerated electron transfer is coincident with the semiconductor physical principles. Upon exposure to light, electron–hole pairs are generated and subsequently separated by an internal electrostatic field in the titanate–TiO2 heterojunction.
研究领域:
材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 9
·12661-12670
·
IF 2.478
Zhang Yun,Jiang Xi,Ding Shihua,Song Tianxiu
Temperature stable microwave dielectric ceramics CoZrNb 2 O 8 - x CaTiO 3 ( x = 1/60 ~ 1/10) were fabricated by a solid-state technique. The phase formation and sintering behavior were detected for the purpose of structure–property relationship exploration. Appropriate rate of CaTiO 3 addition was benefit to the sintering temperature decrease of CoZrNb 2 O 8 . From x = 1/50 to x = 1/10, unexpected CaNb 2 O 6 and Ti 2 Nb 10 O 29 phases both formed, consequent on the chemical reaction between CoZrNb 2 O 8 and CaTiO 3 . Co-based oxide might separate out in the form of liquid phase and decrease the sintering temperature. Increasing CaTiO 3 ration degraded the quality factor Q × f , but at the same time enhanced the dielectric constant ε r and temperature coefficient of resonant frequency τ f . According to the Lichtenecker mixing rule, the estimated microwave dielectric properties basically agreed well with the measured values at first. However, excessive CaTiO 3 incorporation caused lattice defects and gave noticeable deviation. In current work, CoZrNb 2 O 8 -1/40CaTiO 3 composite displayed a rather small τ f with Q × f = 64,600 GHz at 1225 °C.
研究领域:
材料科学
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无机化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2015
·Vol. 3
·期 37
·7449-7456
·
IF 4.726
Xiang Li,Qiuhong Zhang,Zeeshan Ahmad,Jie Huang,Zhaohui Ren,Wenjian Weng,Gaorong Han,Chuanbin Mao
750–850 nm (NIR I) and 1000–1400 nm (NIR II) in the near infrared (NIR) spectra are two windows of optical transparency for biological tissues with the latter capable of penetrating tissue deeper. Monitoring drug release from the drug carrier is still a daunting challenge in the field of nanomedicine. To overcome such a challenge, we propose to use porous Nd3+-doped CaTiO3 nanofibers, which can be excited by NIR I to emit NIR II light, to carry drugs to test the concept of monitoring drug release from the nanofibers by detecting the NIR II emission intensity. Towards this end, we first used electrospinning to prepare porous Nd3+-doped CaTiO3 nanofibers by adding micelle-forming surfactant Pluronic F127, followed by annealing to remove the organic component. After a model drug, ibuprofen, was loaded into the porous nanofibers, the drug release from the nanofibers into the phosphate buffered saline (PBS) solution was monitored by detecting the NIR II emission from the nanofibers. We found that the release of the drug molecules from the nanofibers into the PBS solution triggers the quenching of NIR II emission by the hydroxyl groups in the surrounding media. Consequently, more drug release corresponded to more reduction in the intensity of the NIR II emission, allowing us to monitor the drug release by simply detecting the intensity of NIR II from the nanofibers. In addition, we demonstrated that tuning the amount of micelle-forming surfactant Pluronic F127 enabled us to tune the porosity of the nanofibers and thus the drug release kinetics. This study suggests that Nd3+ doped CaTiO3 nanostructures can serve as a promising drug delivery platform with the potential to monitor drug release kinetics by detecting the tissue-penetrating NIR emission.
研究领域:
纳米医学
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生物材料
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光学成像
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2022
·Vol. 169
·期 5
·052504
·
IF 4.386
Kun Zhao,Kejia Liu
The formation of CaTiO3 during the electro-reduction of TiO2 pellets in CaCl2-based molten salts is unavoidable. So in present paper, the electro-deoxidation of porous CaTiO3 pellets was investigated. Cyclic voltammetry and constant potential electrolysis experiments were conducted to gain insight into the electro-deoxidation mechanism. From the results, two new reduction pathways of the porous CaTiO3 pellets were determined. The main factor influencing the reduction pathways is the porosity. When the porosity is low, CaTiO3 is directly reduced into TiO. With the porosity increases, some CaTiO3 will firstly be reduced into CaTi2O4 and then the CaTi2O4 is further reduced into TiO. The effect of the potential applied on the cathode on the possible reduction limit of the sample was discussed. The results indicated that the more negative the potential is, the faster the deoxidation rate is and the lower the deoxidation limit is. Only when the applied potential is more negative than −1.6 V vs Ag+/Ag, low-oxygen titanium (the oxygen content is lower than 1%) can be obtained in our experimental conditions. In addition, the microstructural kinetics of phase transformations during reduction of the CaTiO3 pellets were also discussed.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Jiamei Zhao,Qiangyi Deng,Ziyin Yang,Hongmei Zhang,Conglu Zhang
In this paper, a high-efficient visible light responsive g-C 3 N 4 /CaTiO 3 /CQDs Z-type heterojunction photocatalyst was successfully prepared by a two-step method for the photodegradation of organic pollutants in water. The combination of g-C 3 N 4 , CaTiO 3 and CQDs could produce synergistic effect, which facilitated the separation of carriers, thereby enhancing photocatalytic activity . The photocatalytic kinetic removal rate of g-C 3 N 4 /CaTiO 3 /CQDs for methylene blue could reach about 8 times of g-C 3 N 4 and 5.5 times higher than that of CaTiO 3 . The effects of co-existing ions, initial pH, water source, and humic acid on meloxicam degradation were examined. Repeatability experiments indicated that the composite had good reusability and stability with 81.1 % removal for meloxicam after four cycles. The main active substances of g-C 3 N 4 /CaTiO 3 /CQDs in free radical capture experiment was ⋅O 2 − . Possible degradation pathways of meloxicam were also analyzed. The results highlight the g-C 3 N 4 /CaTiO 3 /CQDs Z-type heterojunction is a desirable photocatalyst for removing organic pollutants in water.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Fangxu Dai,Ying Wang,Ruiyang Zhao,Xinran Zhou,Jishu Han,Lei Wang
Novel ZnIn 2 S 4 /CaTiO 3 nanocubes were prepared by a two-step method and used as a visible light photocatalyst for efficient hydrogen production . The control of the content of CaTiO 3 could effectively change the photocatalytic H 2 production activity of ZnIn 2 S 4 /CaTiO 3 nanocubes, and the maximum H 2 evolution amount reached to 133116.43 μmol g −1 in 6 h. The photocatalytic hydrogen production efficiency of ZnIn 2 S 4 /CaTiO 3 nanocubes was almost 4.5 times higher than that of pure ZnIn 2 S 4 . The electrochemical impedance spectrum of ZnIn 2 S 4 /CaTiO 3 exhibited the smallest arc radius, time-resolved PL spectrum showed that the carrier lifetime of ZnIn 2 S 4 /CaTiO 3 nanocubes was 3.29 ns, and the photocurrent density of ZnIn 2 S 4 /CaTiO 3 reached to 0.81 μA cm −2 . The prepared ZnIn 2 S 4 /CaTiO 3 nanocubes increased visible light absorption, improved the separation and transfer of photo-generated electrons and holes, and inhibited the recombination of photo-generated electron-hole pairs. ZnIn 2 S 4 /CaTiO 3 nanocubes exhibited the enhanced photocatalytic activity and high stability, and could be used as promising photocatalyst for hydrogen production application.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Fanjun Zeng,Zilong Cao,Changlai Yuan,Fei Liu,Baohua Zhu,Hequn Xiao,Jianwang Wu,Xiao Liu,Liufang Meng,Changrong Zhou,Guanghui Rao
In RF devices, the microwave ceramics possessing an ultrahigh dielectric constant are instrumental in facilitating the miniaturization of electronic components. However, ceramic systems with ultrahigh dielectric constant are rare and typically exhibit poor temperature stability and high dielectric loss. Research on developing new systems with ultrahigh ε r , low dielectric loss, and low τ f is crucial. The microwave ceramics of (1- x ) CaTiO 3 - x AgNbO 3 [(1- x ) CT- x AN, x = 0.4–0.8] were synthesized via solid-state reaction. The XRD and Rietveld analysis data have confirmed that the CT-AN ceramic system is in an orthorhombic structure with a space group of Pbcm . Elevated AgNbO 3 content leads to increased grain size in ceramics. These ceramics possess a high relative density (>98 %) and show excellent microwave dielectric properties. With increasing AgNbO 3 content, the ε r ascends from 106 to 886, while Q×f descends from 1500 GHz to 381 GHz. And τ f fluctuates within a range of 400–1000 ppm/°C, with a minimum of 403 ppm/°C when x = 0.5. Dielectric anomalies due to phase transitions were observed within low-frequency spanning 500 Hz to 200 k Hz, and the dielectric loss is zero at 200 k Hz at 25–100 °C. CT-AN ceramics demonstrate an ultrahigh dielectric constant, and further research into modulating its temperature coefficient of the resonant frequency could unlock their potential for applications in miniaturized antennas and capacitors.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Chen Yang,Xijun Xu,Wajid Ali,Yaojin Wang,Yiping Wang,Ying Yang,Lang Chen,Guoliang Yuan
Ultrasonic sensors are widely applied in industries near room temperature; however, their application at high temperature is still a challenge mainly due to the lack of high-performance piezoelectric ceramics. Here, the 0.364BiScO3–0.636PbTiO3–0.005CaTiO3 ceramic exhibits excellent piezoelectric performances at 20–440 °C. Its piezoelectric coefficient d33 increases from 475 pC/N at 20 °C to 853 pC/N at 360 °C, and then it gradually decreases to 669 pC/N at 440 °C. Furthermore, the planar electromechanical coupling factor kp gradually increases from 0.59 at 20 °C to 0.67 at 200 °C, and then it remains at a stable value of 0.65–0.67 at 150–350 °C. These achievements are because the ceramic morphotropic phase boundaries have a flat Gibbs free energy versus polarization curve and a wide temperature range. Since the piezoelectric ceramic shows satisfactory piezoelectric properties at 20–440 °C, the corresponding ultrasonic sensors can in situ monitor many high-temperature devices, such as engines, wheels, drills, boilers, etc.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Jiamei Zhao,Xinyue Cao,Yibo Bai,Jie Chen,Conglu Zhang
Calcium titanate (CaTiO 3 ) has received more and more attention due to the excellent physicochemical properties. However, in the process of photocatalysis , the photogenerated carriers are very easy to recombine. Based on this problem, g-C 3 N 4 modified CaTiO 3 photocatalyst was prepared via calcination . The properties of CaTiO 3 /g-C 3 N 4 were analyzed through XRD , SEM , XPS , UV–vis and TGA . The optimized CaTiO 3 /g-C 3 N 4 could achieve 100% and 87.7% removal rate of methylene blue (MB) and levofloxacin (LVF), respectively, under a 500 W mercury lamp illumination within 120 min. In addition, the effects of photocatalyst dosage, solution pH and co-existing ions in water on the degradation process were systematically investigated. A possible charge transmission mechanism was analyzed and the LVF degradation pathway was proposed. This work will provide a new strategy to synthesize cost-effective CaTiO 3 composites.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2024
·
IF 9
Xudong Yang,Huan Zhang,Zhiping Zhang,Yameng Li,Hong Liu,Feng Zhang,Guanning Xiang,Quanguo Zhang
The aim of this study was to analyze the effects of CaTiO 3 photocatalysts doped with different concentrations of Fe on the biohydrogen production process by photo-fermentation using corn stover as the substrate. The experimental results showed that the maximum cumulative hydrogen production and the maximum rate of hydrogen production were obtained when the doping concentration was 6 % (g/g) (380.8 mL, 26.4 mL/h), which were 63.4 % and 203.4 % higher, respectively, than those of the blank control group (233 mL, 8.7 mL/h). The substrate conversion rate was 32.82 %. Iron-doped CaTiO 3 lowered the oxygen reduction potential in the fermentation system to provide a suitable reduction environment for the growth and fermentation of photosynthetic bacteria . The lowest redox potential observed was −393.5 mV for 6 % iron-doped CaTiO 3 . Thermogram analysis revealed a strong correlation between cumulative hydrogen production and redox potential. Additionally, the analysis of soluble small molecules showed that iron-doped CaTiO 3 could inhibit the production of ethanol from glycolysis during fermentation and promote the utilization of small molecule acids.
研究领域:
微生物学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Hua Lv,Chayuan Zhou,Qinhui Shen,Yuanfang Kong,Baoliang Wan,Zhiyun Suo,Gongke Wang,Guangtao Wang,Yumin Liu
Developing effective photocatalysts to achieve stable and efficient solar-induced hydrogen production remains a significant challenge due to rapid photocarrier recombination and sluggish hydrogen evolution kinetics. Here, a multi-interfacial engineering strategy involving the decoration of metallic Ni 3 C onto CaTiO 3 /Mn 0.5 Cd 0.5 S was proposed to create an S-scheme/Schottky hybrid heterostructure with multiple carrier transport paths for effective photocatalytic H 2 production. Exploiting the synergy between S-scheme heterojunction and Schottky barrier, the engineered ternary CaTiO 3 /Mn 0.5 Cd 0.5 S/Ni 3 C hybrid heterojunction exhibits outstanding photostability and significantly enhanced hydrogen evolution activity of 79.1 mmol g -1 h −1 , which was about 4.55, 3.22 and 2.59 times greater than Mn 0.5 Cd 0.5 S, Mn 0.5 Cd 0.5 S/Ni 3 C, and CaTiO 3 /Mn 0.5 Cd 0.5 S, respectively. By creating an S-scheme heterojunction between CaTiO 3 and Mn 0.5 Cd 0.5 S, accompanied by a robust internal electric field (IEF), spatial charge separation can be effectively accelerated while ensuring the simultaneous preservation of highly active electrons and holes. Meanwhile, Ni 3 C nanoparticles, acting as a Schottky-junction H 2 generation cocatalyst, can efficiently trap the photoinduced electrons to establish multiple charge transfer channels and supply ample active sites for photoreduction reaction, thereby further optimizing the hydrogen generation kinetics. The integration of a Schottky barrier and S-scheme heterojunction in this research is expected to offer new perspectives for designing other highly effective hybrid catalysts for solar-to-hydrogen fuel conversion.
研究领域:
材料科学
·
能源化学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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