INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2022
·Vol. 46
·期 13
·18465-18476
·
IF 4.672
Yang You,Qingqing Hu,Fupeng He,Yongjie Liu,Qingyun Huang,Xuyang Liu,Zhixiong You,Xuewei Lv
Summary Ammonia gas (NH 3 ) is a clean energy, as well as an efficient reduction and nitridation agent. A novel process of reduction and nitridation with NH 3 followed by magnetic separation and low-temperature selective chlorination to deal with vanadium slag has been proposed. Vanadium spinel (V-Fe spinel, FeV 2 O 4 ) is the main V-bearing phase in vanadium slag, and its reduction and nitridation behavior with NH 3 were investigated in this study. Thermodynamic analysis indicated that the reaction was feasible. The experimental results demonstrated that NH 3 gas was an excellent reagent for reduction and nitridation. DFT calculation proved that NH 3 molecule was easier adsorbed on V atom. The phase component of the final product was Fe/Fe 4 N/VN x O y , whose relative mass fractions obtained by Rietveld refinement analysis were 23.5%, 1%, and 75.5%, respectively. The evolution of iron and vanadium was in the order FeV 2 O 4 → Fe 4 N/Fe 6 N 2−3 → Fe 4 N/Fe and FeV 2 O 4 → V 2 O 3 → VN x O y , respectively. VN x O y was a solid solution, whose O content decreased gradually as the temperature and duration time increased, whereas the N content increased correspondingly. The O content can be decreased to less than 0.10 wt.% after reduction and nitridation at 800°C to 850°C for 3 h.
研究领域:
冶金工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Song Chen,Yulong He,Siyu Ding,Jintao Zhang
To address the low capacity and poor stability of aqueous zinc–iodine batteries owing to the insulating nature of iodine and the shuttle effect of polyiodide, herein, tungsten nitride-modified porous carbon polyhedron (W2N/N-C) was prepared via the pyrolysis of ZIF-8 injected with phosphotungstic acid (PTA@ZIF-8). During the thermal treatment process, the self-nitridation enabled the in situ formation of tungsten nitride nanoparticles in hierarchical porous carbon with nitrogen doping for favorable loading of iodine. When used as the electrode material, the zinc–iodine battery exhibited the low polarization during the charge/discharge process with improved reversibility and good cycling stability for 2000 cycles. The improved electrochemical performance would be attributed to the confinement effect of W2N/N-C for the reversible conversion between iodine and polyiodide, thus enhancing the redox reversibility and utilization of active materials. The present work demonstrates an efficient strategy to prepare porous carbon with metal nitrides via the combination of carbonization and self-nitridation process for high-performing zinc–iodine battery.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2021
·
IF 5.039
Yongjie Liu,Ran Xin,Donglai Ma,Qingqing Hu,Yue Wang,Zhixiong You
Ferrovanadium nitride, which comprises V and N, is an important alloy additive for the production of high-strength low-alloy steel. As an efficient reducing agent and nitrogen source, ammonia gas is widely used in the preparation of metal nitrides. In this study, ferrovanadium nitride alloy powder is prepared by reducing and nitriding VO 2 /Fe 2 O 3 in NH 3 –H 2 gas mixtures with different nitriding potentials. Thermodynamic analysis indicate that the reduction and nitridation of VO 2 and Fe 2 O 3 is feasible. VO 2 is converted into VN, whereas Fe and Fe 4 N can be formed depend on the reaction conditions. Lower temperatures and higher nitriding potentials are beneficial to the formation of Fe 4 N. Based on Rietveld refinement analysis, the formation of Fe 4 N and the atomic occupancy of V and N in vanadium oxynitride, which is associated with the temperature, reaction time, and nitriding potential, is determined. A ferrovanadium nitride alloy powder with an O content of 0.26 wt.% is prepared by reducing and nitriding VO 2 /Fe 2 O 3 at 900 °C for 1 h at a nitriding potential of 4.4 × 10 −3 Pa −0.5 .
研究领域:
材料科学
·
冶金工程
✓ 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
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Shijiao Zhao,Jing Song,Rui Xu,Lei Nie,Jingtao Ma,Changsheng Deng,Xing Cheng,Xingyu Zhao,Shaochang Hao,Jianjun Li
In this study, zirconium nitride nanopowders with a high specific surface area were synthesized by carbothermal nitridation with fructose as a double-function additive. The precursor was prepared by an internal gelation process. The first function of fructose was to act as an organic carbon source for the nitridation reaction to decrease the apparent activation energy . The second function of fructose was to act as a microstructural controller of products to obtain a high specific surface area of 315.7 m 2 /g. The effects of temperature on the phase composition, chemical elements, morphology and specific surface area were investigated. The microstructure development upon heating was illustrated and the relationship between the structure evolution and variation in the specific surface area was elucidated. This method with fructose as a water-soluble organic additive could be expanded to prepare transition metal nitrides with a high specific surface area.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Jia Hongsheng,Li Jiaqi,Niu Rui,Ye Chaochao,Ru Hongqiang,Liu Baochang,E. Yuanlong,Li Haibo
In this work, the Silicon nitride composite ceramics (β-Si 3 N 4 ) by ultra-high pressure sintering were investigated. And the effect of sintering temperature , hold time and α-Si 3 N 4 powders on the sintering process had been analyzed in detail. These experimental results showed the larger particle size and lower porosity had an obvious effect on the thermal conductivity . Meanwhile, the addition of α-Si 3 N 4 powder could be also attributed to thermal conductivity. We had been calculated the porosity of β-Si 3 N 4 composite ceramics that the sample D (0.26%) was lower than the others samples. For a comparison, the thermal conductivity of sample D was up to 64.6 W/m K that was also attributed to its higher diffusion rate and small grain size.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2020
·Vol. 16
·期 13
·1906880
·
IF 11.459
Weikang Wang,Hongjian Zhou,Yanyan Liu,Shengbo Zhang,Yunxia Zhang,Guozhong Wang,Haimin Zhang,Huijun Zhao
It is an important issue that exposed active nitrogen atoms (e.g., edge or amino N atoms) in graphitic carbon nitride (g-C 3 N 4 ) could participate in ammonia (NH 3 ) synthesis during the photocatalytic nitrogen reduction reaction (NRR). Herein, the experimental results in this work demonstrate that the exposed active N atoms in g-C 3 N 4 nanosheets can indeed be hydrogenated and contribute to NH 3 synthesis during the visible-light photocatalytic NRR. However, these exposed N atoms can be firmly stabilized through forming B N C coordination by means of B-doping in g-C 3 N 4 nanosheets (BCN) with a B-doping content of 13.8 wt%. Moreover, the formed B N C coordination in g-C 3 N 4 not only effectively enhances the visible-light harvesting and suppresses the recombination of photogenerated carriers in g-C 3 N 4 , but also acts as the catalytic active site for N 2 adsorption, activation, and hydrogenation. Consequently, the as-synthesized BCN exhibits high visible-light-driven photocatalytic NRR activity, affording an NH 3 yield rate of 313.9 µmol g −1 h −1 , nearly 10 times of that for pristine g-C 3 N 4 . This work would be helpful for designing and developing high-efficiency metal-free NRR catalysts for visible-light-driven photocatalytic NH 3 synthesis.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Song Wu,Yongfeng Xia,Ming Zhu,Jun Zhao,Dongxu Yao,Yu-Ping Zeng
Si 3 N 4 ceramics now face new applications and challenges in the semiconductor field. The preparation of h-BN/Si 3 N 4 machinable ceramics incorporating 5–30 vol% h-BN via hot-pressing was carried out. This study systematically explored how the varying h-BN content influenced the composite's microstructure, mechanical attributes, and machinability . The results showed that some of the h-BN was encapsulated by growing Si 3 N 4 grains to form an intragranular structure during the process of hot-pressing, while the remaining h-BN exhibited uniform distribution along grain boundaries. The Si 3 N 4 phase transition in composites was inhibited by excessive h-BN, accompanied by a higher decrease in densification. The sample containing 20 vol% h-BN exhibited the best comprehensive performance, with high mechanical strength and excellent machinability. The bending strength and fracture toughness remained high at 862 MPa and 10.3 MPa m 1/2 , and could be effortlessly machined with cemented carbide drills. Additionally, the machinability of the composites was systematically characterized through observations of crack propagation paths, fitting of R-curves, and mechanical drilling tests.
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
Materials Research Express
·
2019
·Vol. 6
·期 7
·075314
·
IF 1.449
Lu Chen,Chao Xiao,Yunlu Tang,Xian Zhang,Kang Zheng,Xingyou Tian
A multilayered thermally conductive composite with ternary system of heat conductive fillers-thermally conductive films-epoxy matrix was prepared through a facile process of layer-by-layer stacking, pre-curing and hot-pressing. The thermally conductive films (boron nitride nanosheets/cellulose nanofiber) with high in-plane thermal conductivities were employed as the heat conductive medium, while the platelet-shaped hexagonal boron nitride and the particle-shaped aluminum nitride were utilized as heat conductive fillers for enhancing the perfection of the thermally conductive network. A horizontally heat conductive network was constructed within the epoxy matrix under the joint contribution of the horizontally aligned hexagonal boron nitride platelets and the parallelly spread thermally conductive films through hot-pressing. The aluminum nitride particles acted as linking points, filling the gaps between hexagonal boron nitride platelets, while constructing the thermally conductive path in the vertical direction. Thanks to the introduction of thermally conductive films and the good orientation of boron nitride platelets, the in-plane thermal conductivities of the composites increased with increasing of film layer number. With film layer number of 9, and filler content of 30 wt% (aluminum nitride/boron nitride (1:1)), the in-plane thermal conductivity of the composite was as high as 8.53 W m−1 * K, which showed an enhancement of 4165% than that of the pure epoxy matrix, and an improvement of 613% compared to that of the composite without multilayered structure. Meanwhile, the out-of-plane thermal conductivity exhibited a slightly deceased tendency as film layer number increased, but it still reached 0.87 W m−1 * K with film layer number of 9, which was 335% higher than that of the pure epoxy. In addition, the multilayered composite also possessed good thermal stability, enhanced stiffness, as well as low dielectric constant and dielectric loss, which shows a potential application in thermal management for packaging of integrated circuit and microelectronic devices.
研究领域:
材料科学
·
热管理技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Kezhuo Li,Jin Luo,Longhao Dong,Gaoqian Yuan,Wen Lei,Quanli Jia,Haijun Zhang,Shaowei Zhang
Porous ceramics have attracted extensive attention because of their high porosity, low thermal conductivity , large specific surface area and good corrosion resistance . In this work, TiN porous ceramics with high porosity are successfully prepared via the combination of freeze-drying and in-situ nitridation reaction method using Ti powder and chitosan as raw materials. The influence of the solid content of Ti powder, the concentration of chitosan/acetic acid solution and the nitridation temperature on the morphologies and physical properties of as-prepared TiN porous ceramics are fully investigated. The sample with high porosity of 92.8% and low bulk density of 0.27 g/cm 3 can be obtained through optimal parameters (the solid content of Ti powder is 9.6 wt%, the concentration of chitosan/acetic acid solution is 5 wt%, and the nitridation temperature is 1473 K). Particular emphasize is that the as-prepared TiN porous ceramics can be used as sulfur host material for lithium-sulfur batteries (LSBs). Good rate performance and cycle stability of TiN/S electrodes are achieved by electrochemical performance tests. The initial discharge capacity of TiN/S electrodes is 778 mAh g −1 at 0.5C, and the capacity retention rate is 94% after 200 cycles.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Qiang Zhi,Bo Wang,Shan Zhao,Zhao Zhang,Yu-Chen Deng,Nan-Long Zhang,Jian-Feng Yang
Highly porous Si 3 N 4 ceramics have been prepared via a novel carbothermal reduction-nitridation (CRN) reaction between carbon nanotubes (CNTs) and SiO vapor in a N 2 atmosphere. The green bodies consisted of 49.0 wt% CNT, 40.4 wt% α-Si 3 N 4 as seed and 10.6 wt% Y 2 O 3 as sintering additive, and SiO powders were located under the green bodies during sintering. By heating at temperatures ranging from 1550 to 1650 °C, fibrous β-Si 3 N 4 nanograins were obtained. Complete reaction was achieved after soaking at 1650 °C, and a mean grain diameter of approximately 290 nm and aspect ratio of as high as 20 were obtained, and a porosity of 73% was reached due to the low density of the green bodies. The bending and compressive strengths were up to 62 MPa and 82 MPa, respectively, which were higher than the values in the literature, as a result of the fine elongated fibrous β-Si 3 N 4 grains. It should be noted that the Si 3 N 4 ceramics exhibited a large strain to failure and ‘pseudoplastic’ deformation behavior during the compressive test, which was attributed to the high porosity.
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
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2020
·Vol. 95
·期 2
·398-407
·
IF 2.008
Zhao Shijiao,Xu Rui,Ma Jingtao,Lin Xuping,Cheng Xing,Zhao Xingyu,Hao Shaochang,Deng Changsheng
Zirconium nitride microspheres with uniform size of ~680 μm, good sphericity, and good integrity were prepared by internal gelation process and two-step nitridation. The effects of carbon black and temperature on stability of sol were investigated. Induction of carbon black decreased stability of sol but the amount of carbon black added has little effect on the sol stability. Increasing temperature linearly decreased the stable time of the sol. Sol with stable time of up to 1 h, which was adequate for casting of liquid spheres was achieved at 11.0 °C, a significant increase from conventional 4.0 °C. Two-step nitridation was developed to prepare crack-free ceramic microspheres with high relative nitride phase content. The special microstructure on surface and cross section of microspheres reveals stepped-growth of nitride crystals.
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
危险品化学品经营许可证（带存储）