NANO
·
2022
·
IF 1.438
Kaiyue Liang,Mingcai Yin,Yixian Li,Yaoting Fan,Zhongjun Li
CdS and MoS 2 are both promising photocatalytic materials for hydrogen production and lots of MoS 2 /CdS composites have been investigated. However, most of the previous work focused on relatively stable hexagonal CdS; researches on cubic CdS are still rare mainly due to its unstability. Then in this paper, a ternary composite MoS 2 /CN/CdS composed of cubic CdS, MoS 2 and graphitic carbon nitride (g-C 3 N 4 , abbreviated as CN) was prepared by simple in situ precipitation of cubic CdS on MoS 2 /CN at room temperature. Based on a series of characterizations, the photocatalytic hydrogen production performance of MoS 2 /CN/CdS was studied. The results showed that when the amount of MoS 2 /CN was 10 wt.%, the activity reached 1253.2 μ mol h − 1 , about 110 times that of pure CdS. Especially, its stability was investigated in detail by cyclic hydrogen production tests, which indicated that although the activity decreased after the first cycle, it was stable in the following three cycles mainly due to the existence of CN. Namely, a relatively stable and high performance cubic CdS-based ternary composite was achieved. This research can provide some new insights into the design of cubic CdS-based photocatalysts.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Jaures Syntyche Ndzila,Zhengmao Ye,Guojian Jing,Xiaolei Lu,Jiaming Wu,Jinpu Zhang,Shuxian Wang,Xin Cheng
Sr 4 Al 6 SO 16 is a kind of anhydrous sulfoaluminate that belongs to the sodalite family. In this paper, we demonstrate the effect of Fe 3+ ions addition on the hydration properties of two polymorphs of Sr 4 Al 6 SO 16 (namely pure orthorhombic and cubic). In solid-state reaction of orthorhombic Sr 4 Al 6 SO 16 , excessive 5 wt% SrSO 4 was used to compensate for the loss of sulfur. Results indicate that the hydration rate of cubic phase is faster than that of orthorhombic phase at early stage, but the heat release of the latter is more concentrated. The reason why the cubic phase has a faster earlier hydration kinetics may be due to the incorporation of Fe 3+ ions and the formation of SrFe 12 O 19 impurity phase, which introduce the defects in the structure, activate the crystal lattice , and increase the hydration activity. Both polymorphs react with water to form the reaction products first, and then no crystalline phase hydration product was precipitated after 72 h. In contrary to the XRD , amorphous AH 3 was clearly detected in TGA analysis in hydrated samples, probably due to poor crystallinity which cannot be detected by XRD. In addition, both polymorphs contain a lot of impurity phases, and their amounts are calculated using the Rietveld refinement method. Moreover, the addition of Fe 3+ ions is not only beneficial to adjust the cubic phase content, but also facilitates the relative particle growth. This work provides a useful platform for employing the Fe 3+ ions to regulate the hydration properties of Sr 4 Al 6 SO 16 .
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2019
·Vol. 21
·期 9
·1389-1396
·
IF 3.382
Zhuo Chen,Lvming Dong,Hanchuan Tang,Yan Yu,Lei Ye,Jianfeng Zang
One-dimensional all-inorganic halide perovskites have emerged as one of the most prominent materials in the application of optoelectronic devices due to their remarkable properties such as a low number of defects, morphological anisotropy, mechanical flexibility and fast charge transfer capability. Particularly, cubic (α) phase CsPbI3 has the narrowest band gap of 1.73 eV among all-inorganic lead halide perovskites, exhibiting the greatest potential in solar cell applications. However, the direct synthesis of room temperature stabilized α-CsPbI3 nanowires is challenging and remains unfulfilled because the synthesis reaction usually involves a phase change process, resulting in an undesired orthorhombic (δ) phase with a wider bandgap of 2.82 eV. Here, we report a low-temperature approach to directly synthesize highly stabilized α-CsPbI3 nanowires. Low reaction temperature, capping ligand protection, and extended growth time are employed to successfully grow α-CsPbI3 nanowires. The as-synthesized α-CsPbI3 nanowires are 10–20 μm in length and 5–80 nm in diameter. The X-ray diffraction (XRD), photoluminescence (PL), and UV-vis absorption results verify that these cubic phase nanowires maintain excellent stability at room temperature for 90 days. The CsPbI3 nanowires show a PL peak located at around 685 nm and the UV-vis absorption spectrum further reveals that the band gap is about 1.77 eV. The excellent optical properties of the phase-stable CsPbI3 nanowires offer great potential in the field of optoelectronic devices.
研究领域:
材料科学
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2013
·Vol. 97
·期 3
·990-995
·
IF 2.107
Kuo Jiang,Songbai Liu,Yuan Li,Yaofei Li
Powders of zirconia doped with 8 mol% REO 1.5 (RE = Yb, Y, Gd, and Nd) were synthesized by using the sol–spray pyrolysis method. The effects of RE 3+ ionic radius on monoclinic (m) phase content of powders were investigated. The XRD results showed that the metastable tetragonal (t′) phase underwent a complete phase change to form m and cubic (c) phases after a heat treatment of 50–100 h at 1450°C. A cation size-dependent reduction in the m phase content of the REO 1.5 partially stabilized ZrO 2 powders was observed. The SEM–EDS analysis of the powders revealed that the RE 3+ concentrations in the c phases decreased with decreasing the RE 3+ ionic radius. These results indicate that the stabilizer concentration of the c phase can be attributed to RE 3+ ionic radii, resulting in different m phase contents. Compared to the REO 1.5 single doped ZrO 2 , the m phase contents of 8 mol% (RE 0.5 Yb 0.5 )–ZrO 2 (RE = Y, Gd, and Nd) powders were significantly reduced. The results prove that the stabilizer with a lower RE 3+ size is effective in reducing the m phase content of partially stabilized ZrO 2 after annealing at high temperatures.
研究领域:
材料科学
·
陶瓷学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Manjiao Deng,Mao Ye,Tao Li,Haitao Huang,Wen-Xiang Yuan,Heng Jiang,Peng Lin,Xierong Zeng,Shanming Ke
Ferroelectric perovskite KNbO 3 (KNO) nanosheets with cubic and orthorhombic phases were synthesized by a simple soft chemistry exfoliation at room temperature. KNO nanosheets could be simply obtained by peeling off the layered precursor K 2 NbO 3 F in water, while the phase structure of KNO could be controlled by using different precursors. The cubic KNO nanosheets were formed by exfoliating-restacking, while the orthorhombic nanosheets were produced by nucleation-ripening. The photocatalytic performance of these nanosheets has been exploited in degradation Rhodamine B dye. The cubic KNO nanosheets showed obviously better photocatalytic activity, which could be ascribed to its highest symmetry in the bulk structure and its unique electron structure. The high activity of the ferroelectric two dimensional nanosheets indicates a broad spectrum of applications in the photocatalyst fields.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Biyi Xu,Huanan Duan,Wenhao Xia,Yiping Guo,Hongmei Kang,Hua Li,Hezhou Liu
A multistep sintering schedule is developed to synthesize Li 7 La 3 Zr 2 O 12 (LLZO) doped with 0.2 mol% Al 3+ . The effect of sintering steps on phase, relative density and ionic conductivity of Al-doped LLZO has been evaluated using powder X-Ray diffraction (XRD), scanning electron microscopy (SEM), 27 Al magic spinning nuclear magnetic resonance (NMR) spectroscopy and electrochemical impedance spectroscopy (EIS). The results show that by holding the sample at 900 °C for 6 h, the mixture of tetragonal and cubic garnet phases are obtained; by continuously holding at 1100 °C for 6 h, the tetragonal phase completely transforms into cubic phase; by holding at 1200 °C, the relative density increases without decomposition of the cubic phase. The Al-LLZO pellets after multistep sintering exhibit cubic phase, relative density of 94.25% and ionic conductivity of 4.5 × 10 −4 S cm −1 at room temperature . Based on the observation, a sintering model is proposed and discussed.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Yanhua Zhang,Wenjia Luo,Dongwei Hu,Yuxin Deng,Yuan Chen,Jiadong Deng
Traditional preparation method of solid electrolyte Li 7 La 3 Zr 2 O 12 requires a very long sintering holding time (> 36 hours). A efficient and mass production method, microwave sintering, is utilized to prepared LLZO by which the sintering time is reduced to be 2 ~ 4 h. Results show that cubic phase LLZO can be obtained at 1150 o C ~ 1200 o C. With the increase of holding time from 1 h to 4 h, tetragonal LLZO transforms to cubic which suggests extra thermal energy is generated by coupling dielectric loss with microwave. Pellet sintered with 4 h reaches the highest ionic conductivity of 3.1 x 10 -4 S cm -1 . Long holding time of 6 h will take away a lot of Li from the grain to form excess glass-like phase which is not favorable for conductivity.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 43
·34451-34455
·
IF 3.84
Yu Liu,Weidong Chi,Hui Liu,Yueyang Su,Liang Zhao
Cubic and tetragonal ZrO2 were synthesized by a sol–gel method using ethanol and glycerol as solvents and ZrOCl2·8H2O as zirconium source. The effect of phase stabilization with amorphous carbon was observed and discussed. The structural evolution, phase transformation and morphological characteristics of powders were investigated by thermogravimetric analysis (TG), differential scanning calorimetric analysis (DSC), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Cubic and tetragonal phase could be generated in this system.
研究领域:
材料科学
·
陶瓷学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Yu Han,Yonghui Chen,Xueting Pei,Maolin Zhang,Dongyan Zhang,Zhimin Li,Guozhong Cao,Yuan Wang
The development of Li 7 La 3 Zr 2 O 12 solid state electrolyte is retarded by its low ionic conductivity and surface passivation. A few studies suggest those two hurdles can be solved together. Capitalizing on similar physical and chemical properties of Hf 4+ and Zr 4+ , Hf 4+ doped Li 7 La 3 Zr 2- x Hf x O 12 ( x = 0.3, 0.4, 0.5, and 0.6) is prepared and the influence of Hf 4+ on the structure and electrochemical performance of LLZO is investigated systematically. LLZO with Hf 4+ doping is transformed into cubic phase, and also reduces the secondary reaction between H 2 O, CO 2 and LLZO, while increasing the ionic conductivity of the electrolyte to 2.01 × 10 −4 S cm −1 . The electrochemical window between the LLZHO and lithium metal reaches 4.7 V, which is 0.8 V higher than that of LLZO. The specific capacity of the 1st discharge of the all-solid-state batteries assembled with the LiFePO 4 cathode at 0.1C reaches 110.00 mAh·g −1 . The coulombic efficiency reaches 99.18 % after 100 cycles, and the cycle retention rate is 65.82 %.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 34
·20746-20751
·
IF 3.361
Raheel Ahmed Janjua,Obaid Iqbal,Muhammad Aqeel Ahmed,Abdullah A. Al-Kahtani,Sara Saeed,Muhammad Imran,Abdul Ghafar Wattoo
A comprehensive strategy has been developed to construct nano-sized homogeneous and heterogeneous core/shell structures of NaYF4 host. Synthesis conditions of cubic phase/α-NaYF4 and hexagonal phase/β-NaYF4 are discussed. Pure cubic NaYF4:Yb,Er nanocrystals were synthesized with different average sizes extending from 7 nm to 15 nm by varying the reaction time. Temperature and time thresholds of hexagonal nucleation were determined and utilized for controlled core/shell structures of different phases. α-NaYF4:Yb,Er@α-NaYF4, α-NaYF4:Yb,Er@β-NaYF4, β-NaYF4:Yb,Er@α-NaYF4, and β-NaYF4:Yb,Er@β-NaYF4 core/shell structures were prepared by adopting the required conditions to achieve the desired phase. Excess sodium was used to grow hexagonal shell over metastable cubic core under controlled conditions of reaction time and temperature to prevent the structural transition of the core. Upconversion emission spectra have also been obtained. UCL integrated intensities demonstrated about 5-fold enhancement for α-shell over α-core as compared to the core alone and 22-fold enhancement with β-shell. On the other hand, α-shell over β-core exhibited 5-fold enhancement and β-shell over β-core exhibited 6-fold enhancement.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Wenjin Yang,Jing Li,Xinglai Zhang,Cai Zhang,Xin Jiang,Baodan Liu
The peculiar physical and chemical properties of 2D nanostructures have aroused global research interest in developing new members, synthetic technology, and exploring their potential applications in functional nanodevices. However, it is extremely challenging to directly obtain the 2D nanosheets for these extrinsic layered structures using conventional routines. In this work, we demonstrate the facile and general synthesis of 2D spinel-type metal oxides nanosheets through a simple hydrothermal reaction. Using this method, cubic γ-Ga2O3, ZnGa2O4 and MnGa2O4 nanosheets with triangular/hexagonal configuration and ultrathin thickness have been synthesized, and all these nanosheets show preferential growth along (111) plane with the minimum formation energy. Microstructural and composition analyses using HRTEM, EDS, XPS, and so on reveal that the as-synthesized 2D nanosheets are well-crystallized in cubic fcc-phase and show high purity in composition, and the formation process of MGa2O4 nanosheets can be regarded as the competition of M2+ and Ga3+ in tetrahedral site. Spatially resolved cathodoluminescence measurement of individual 2D nanosheet shows that the γ-Ga2O3, ZnGa2O4, and MnGa2O4 nanosheets exhibit distinct luminescence behavior, and ZnGa2O4 nanosheets show the strongest emission in visible region. It is expected that the facile synthesis of spinel-type metal oxides of γ-Ga2O3, ZnGa2O4, and MnGa2O4 nanosheets will further promote the exploration of a variety of semiconductor nanostructures that could not be achieved using conventional technology suitable for layered structures and will also open up some opportunities for the integration of advanced functional nanodevices such as photodetectors, phosphors on the basis of them.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 103
·101707-101713
·
IF 3.289
Shengjun Zhang,Jiajia Zhou,Ruozhen Wu,Lei Lei,Zhen Xiao,Junjie Zhang,Shiqing Xu
Lanthanide (Ln3+)-doped nanoparticles that produce strong red upconversion (UC) luminescence are desirable for biological applications. For nanoparticles, modification of their electronic properties and stabilization of their crystallographic phase are crucial for tuning their luminescence behaviors. Here, Yb3+–Er3+ doped Gd2O3 nanoparticles have been synthesized by calcining Gd2O2S in nitrogen (O2-free) and ambient air (∼21% O2), respectively. Various approaches including X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy and thermo-gravimetric and differential thermal analyses (TG-DTA) were used to characterize the structure, morphology and phase formation mechanism of the nanoparticles. Upconversion luminescence properties were investigated by emission intensity vs. excitation power (double logarithmic relationship) and temperature dependent emission spectroscopy. The different splitting transition probabilities of the cubic and/or monoclinic phase, the probability of multiphonon relaxations and cross relaxations between Er3+ ions are responsible for the efficient red emission in the cubic Gd2O3 nanoparticles. More importantly, the lower phonon energy of the pure cubic sample has good thermal stability in the current detectable range of 20–100 °C. These results imply that the cubic Gd2O3 upconversion nanoparticles may have multiplexing functionality in bio-imaging.
研究领域:
材料科学
·
生物医学工程
·
光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）