KEY ENGINEERING MATERIALS
·
2016
·
IF 0
Shen Qi,Xiao Jian Mao,Bao Yan Chai,Long Zhang
Transparent aluminum oxynitride (AlON) ceramics have been prepared through a method based on direct reaction sintering of alumina and aluminum nitride powders using MgO and Y2O3 as co-additives. The sintering additives could cause the formation of liquid phase during sintering, which would greatly promote the densification and eliminate pores. The grain size of AlON is about 50-100μm. The influence of different component of Al2O3 and AlN as well as sintering temperature on microstructure and optical properties of AlON have been studied. High transparent AlON ceramics with the in-line transmittance of 80.3% at 2000 nm wavelength have been prepared when the concentration of sintering additives was 0.16wt% Y2O3 and 0.02wt% MgO.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
·
IF 2.93
Li Zhang,Yan Song,Jianyong Feng,Tao Fang,Yujiao Zhong,Zhaosheng Li,Zhigang Zou
Lanthanum tantalum oxynitride (LaTaON 2 ) powders were prepared by one-step flux method. LaTaON 2 photoanodes, which are fabricated by using LaTaON 2 powders, are found to exhibit photoelectrochemical activity for overall water splitting . The photocurrent for LaTaON 2 photoelectrodes was ca. 120 μA cm −2 at 1.5 V vs. reversible hydrogen electrode (RHE) in 1 M NaOH aqueous solutions (pH = 13.6) under AM 1.5 G simulated sunlight irradiation (100 mW cm −2 ). The photocurrent of LaTaON 2 photoelectrode from back-side illumination is much larger than that from front-side illumination, suggesting that the photoelectrochemical property is mainly limited by poor continuous electron transport in the bulk. Further efforts to ameliorate the electron transport in the bulk of LaTaON 2 photoelectrodes are expected to significantly improve their photoelectrochemical performance.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Shan-Lu Chen,Wei-Ming Guo,Shi-Kuan Sun,Yuji Masubuchi,Ming Lv,Hua-Tay Lin,Cheng-Yong Wang
In this work, nearly single phase SrTaO 2 N powder was directly prepared from strontium carbonate (SrCO 3 ) and tantalum mononitride (TaN), instead of the nitridation of the oxide precursors using NH 3 . The phase evolution and reaction mechanism together with the chemical composition, crystal structure and particle size of SrTaO 2 N product were investigated. Similar to the reactions between SrCO 3 and Ta 3 N 5 , the evolution of CO 2 , CO and N 2 was detected during the reactions. The results revealed that this novel reaction was able to successfully synthesize orange-coloured SrTaO 2 N powder with nearly pure phase at 1200 °C and the powder possessed the uniform size distribution with the mean diameter of 6.63 µm.
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 Physical Chemistry C
·
2017
·
IF 4.536
Bi Zhang,Jiang-Wei Zhang,Hao Zhong,Lu-Yuan Hao,Xin Xu,Simeon Agathopoulos,Chengming Wang,Liang-Jun Yin
A highly stable hydrophobic Ba2SiO4:Eu2+ (BSO) phosphor was produced by forming a robust hydrophobic inorganic silicon-oxy-imide-carbide layer on its surface. The process for developing this layer involved coating, ammonolysis, and pyrolysis of chlorosilane. The tightly adhered coating layer had a lotus, leaf-like micro- and nanohierarchical structure and contained CH3 groups, which enhanced the hydrophobicity of the modified phosphor significantly. The modified phosphors treated at 500 °C exhibited remarkable stability in their emission spectra, even after exposure to high-pressure water steam at 100 °C for 48 h, which is attributed to the high stability of the surface layer.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Shunhang Wei,Xiaoxiang Xu
Perovskite oxynitrides often own a poor photocatalytic activity under normal conditions, being incommensurate to their strong visible light absorbance. This is particularly true for SrTaO 2 N which undergoes self-oxidative decompositions even under protection of a hole scavenger. In this work, we laminate the crystal structure of SrTaO 2 N by inserting extra layers of SrO to form a Ruddlesden-Popper (RP) compound Sr 2 TaO 3 N. This structural modification not only improves the light absorption of SrTaO 2 N but also effectively suppresses the defect formation such as Ta 4+ species etc. More importantly, Sr 2 TaO 3 N is able to drive photocatalytic water oxidation reactions under visible light illumination (λ ≥ 420 nm) without the aid of a cocatalyst and self-oxidative decompositions found for SrTaO 2 N are largely inhibited. Further analysis suggests that the presence of extra SrO layers positively shifts the valence band edge and stabilizes N species in the structure according to Pauling’s second rule. Theoretical calculations indicate that Sr 2 TaO 3 N has typical 2D charge transportation properties which are associated with the structural laminations. Its conduction band minimum (CBM) and valence band maximum (VBM) are found to be located within TaN 2 O 2 square planes which favors efficient charge transportations.
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 THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Jian Yang,Yu Cong,Junrong Ling,Wentao Xu,Ye Zhang,Youfu Zhou,Maochun Hong
Aluminum oxynitride (AlON) powders were synthesized by a novel carbothermal reduction and nitridation (CRN) method. Homogenous and fluffy AlOOH/C core-shell nanoparticle precursor was hydrothermally synthesized with aluminum nitrate hydrate, sucrose and urea as starting materials. Then single-phase AlON powders were synthesized by CRN method at 1700 °C for 2 h. The phase transition and growth of Al 2 O 3 particles was effectively retarded by the amorphous carbon nano-layers on the surface of precursor, resulting in significantly lower reaction temperature and further smaller particle size. Based on above fine AlON raw material, transparent AlON ceramic was prepared by pressureless sintering at 1880 ℃ with the in-line transmittance above 80 %.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Wen-Bin Niu,Shi-Kuan Sun,Wei-Ming Guo,Shan-Lu Chen,Ming Lv,Hua-Tay Lin,Cheng-Yong Wang
The perovskite-structure group oxynitrides BaTaO 2 N and SrNbO 2 N, usually obtained by ammonolysis of the oxide precursors, were prepared by the reaction between the corresponding alkaline earth carbonate and tantalum nitride or niobium nitride in the flow of nitrogen. The chemical composition and particle morphology of the products were investigated as well as the phase path and reaction mechanism. It was found that the nearly single phase oxynitride phases formed at 1200–1300 °C, where the partial oxidation of nitrides and the absence of oxide impurities was achievable. The products were deficient in nitrogen content and formed with a fine particle size with the narrow size distribution.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Jingzhu Zhou,Qiong Qu,Wenwen Zhang,Hongyu Wang,Dongsheng Zhang,Guihua Liu
The inherent volume expansion of sulfur, the low conductivity of sulfur species, and the shuttle effects of lithium polysulfides (LiPSs) have limited the commercial deployment of lithium–sulfur (Li–S) batteries. Herein, a tungsten oxynitride skeleton featured with a three-dimensional ordered macroporous (3DOM) structure and embedded with ZIF-67-derived Co-NC nanoparticles (S/Co-NC/WNO) is developed as an effective sulfur host in Li–S batteries. The stable and unique 3DOM structure is conducive to electrolyte permeation and reduces the influence of the volume expansion. Nitrogen doping not only enhances the electrical conductivity of WO3 but also favors LiPS trapping. Meanwhile, Co-NC nanoparticles act as catalytic centers, promoting LiPS adsorption and catalytic conversion, leading to quick and durable Li–S chemistry. Therefore, S/Co-NC/WNO exhibits outstanding electrochemical performance. The initial discharge capacity is 1028.5 mAh g–1 at 0.2 C, and after 100 cycles, a discharge capacity of 938.0 mAh g–1 is maintained. Even under a sulfur loading of 8 mg cm–2, the Li–S battery was capable of reaching an areal capacity of 5.54 mAh cm–2. In addition, the flexible pouch cell based on S/Co-NC/WNO cathode also achieved stable cycling performance, which demonstrates its promising potential in Li–S battery applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Weixuan Zeng,Yuan Bian,Sheng Cao,Yongjin Ma,Yi Liu,Anquan Zhu,Pengfei Tan,Jun Pan
Tantalum oxynitride-based materials, which possess narrow band gaps and sufficient band energy potentials, have been of immense interest for water splitting. However, the efficiency of photocatalytic reactions is still low because of the fast electron–hole recombination. Here, a Sr2Ta2O7–xNx/SrTaO2N heterostructured photocatalyst with a well-matched band structure was in situ constructed by the nitridation of hydrothermal-prepared Sr2Ta2O7 nanosheets. Compared to Sr2Ta2O7–xNx and pure SrTaO2N, the Sr2Ta2O7–xNx/SrTaO2N heterostructured photocatalyst exhibited the highest rate of hydrogen evolution, which is ca. 2.0 and 76.4 times of Sr2Ta2O7–xNx and pure SrTaO2N, respectively, under the similar reaction condition. The enhanced performance arises from the formation of suitable band-matched heterojunction-accelerated charge separation. This work provides a promising strategy for the construction of tantalum oxynitride-based heterojunction photocatalysts.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Jian Yang,Haitao Zhang,Yanan Li,Wentao Xu,Youfu Zhou,Maochun Hong
Single-phase aluminum oxynitride (AlON) powders were synthesized by improved direct nitridation (DN). The improved DN method is to obtain high quality powder by adding high nitrogen pressure on the basis of ordinary DN method. Compared with the ordinary DN method, the average particle size of the synthesized powder is reduced by about 20 μm, the morphology tends to be spherical and the sintering activity is higher. Using different particle size α-Al 2 O 3 precursor, a modified DN method was adopted to synthesize spherical, good dispersibility and fine AlON powders. The influence of particle size of raw material α-Al 2 O 3 on sintering properties was investigated. Transparent AlON ceramics with dimensions of φ 103mm × 3 mm with in-line transmittance greater than 80%were fabricated by pressureless sintering from above AlON powders. In addition, the effects of different nitrogen pressure on the morphology, particle size distribution and average particle size of synthetic powder were investigated. On this basis, the differences between DN method and improved DN method on synthetic powder and the possible synthesis mechanism were proposed.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Baofeng Zheng,Yanhua Song,Zhibo Zheng,Yanxia Zhao,Qing Yang,Zhan Shi,Bo Zou,Haifeng Zou
A novel green-light-emitting silicon-based oxynitride phosphor Ca4Y3Si7O15N5:Eu2+ with low thermal quenching and ideal pressure sensitivity is reported. The Ca3.99Y3Si7O15N5:0.01Eu2+ phosphor can be efficiently excited by 345 nm ultraviolet light and shows very low thermal quenching (integrated and peak emission intensities at 373 and 423 K were 96.17, 95.86, and 92.73, 90.66% of those at 298 K, respectively). The correlation between high thermal stability and structural rigidity is investigated in detail. The white-light-emitting diode (W-LED) is assembled by depositing the obtained green-light-emitting phosphor Ca3.99Y3Si7O15N5:0.01Eu2+ and commercial phosphors on a ultraviolet (UV)-emitting chip (λ = 365 nm). The CIE color coordinates, color rendering index (Ra), and corrected color temperature (CCT) of the obtained W-LED are (0.3724, 0.4156), 92.9, and 4806 K, respectively. In addition, when subjected to in situ high-pressure fluorescence spectroscopy, the phosphor exhibits an evident red shift of 40 nm with an increase in pressure from 0.2 to 32.1 GPa. The phosphor has the advantage of high-pressure sensitivity (dλ/dP = 1.13 nm GPa–1) and visualization with pressure changes. The possible reasons and mechanisms are deeply discussed in detail. Based on the above advantages, Ca3.99Y3Si7O15N5:0.01Eu2+ phosphor is expected to have potential applications in W-LEDs and optical pressure sensing.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 30
·e55699
·
IF 2.7
Xuemei Bai,Jingmin Luan,Tingting Song,Haifeng Sun,Baolin Yan,Yuhua Dai,Jianxiang Yu
Graphitic carbon nitride (g-C 3 N 4 ) has received much attention as a metal-free photocatalyst for dye degradation and sterilization. However, the low photocatalytic bactericidal activity and the difficulty in recycling have limited its applications. Here, oxidatively modified g-C 3 N 4 grafted with polyethyleneimine (PEI) nanofiber membranes (PVA/PEI-OCN) was reported to enhance the photocatalytic activity. The modification by PEI grafting could reduce the recombination rate of photogenerated carriers and lead to more electrons for the photocatalytic reaction. In addition, electron spin resonance (ESR) results showed that the generation of reactive oxygen species (˙OH, ˙O 2 − and 1 O 2 ) were significantly enhanced in photocatalysis, leading to the significant enhancement of photocatalytic bactericidal activity and dye degradation. Furthermore, the PVA/PEI-OCN nanofiber membranes prepared by electrospinning had smooth surfaces and uniform fiber formation, with an average diameter of 380 ± 60 nm. The tensile strength was about 73.5% higher than that of PVA nanofiber membranes. The inhibition diameter of PVA/PEI-OCN-4 against Escherichisa coli ( E. coil ) could reach 20 ± 0.2 mm, and the maximum degradation efficiency of methylene blue solution (10 mg/L) could reach 92.8% within 120 min. This work provided an effective paradigm for the rational design of metal-free photocatalytic materials for elimination of bacterial and dye contamination.
研究领域:
材料科学
·
环境科学
·
生物学
✓ 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）