OPTICAL MATERIALS
·
2023
·
IF 3.9
Ke Sun,Haibin Lin,Rui Zhang,Jinlong Zhu,Liping Wang,Songbai Han,Xiaofei Wang
The emerging laser-driven phosphor-converted white laser diodes (w-LDs) demand highly efficient and thermally stable color converters. To this end, the Ce 3+ luminescence in the rekindled La–Si–O–N host, and the impacts of NH 4 Cl flux and post-processing are investigated systematically. On the basis of the XRD results, well crystalline Ce 3+ -doped La 5 Si 3 O 12 N and LaSiO 2 N are obtained at 1600 °C for 5 h and 1500 °C for 4 h, respectively. Impressively, the representative La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ exhibit a broad excitation band from 240 nm to 400 nm, peaking at around 360 nm, which is well matched with emission from near-UV (n-UV) chip. Under excitation by a n-UV laser, the La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ produce bright blue light in a wide emission band from 360 nm to 550 nm. The CIE chromaticity diagram reveals the tunability of the hue of these phosphors. The quenching temperature is determined to be 396 K and 429 K for La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ respectively, indicating superior thermal stability. The addition of 3 wt% NH 4 Cl flux much enhances the emission intensity of both La 5 Si 3 O 12 N:0.04Ce 3+ and LaSiO 2 N:0.03Ce 3+ . Furthermore, the post-treatments markedly improve the luminescence properties by increasing the crystallinity , reducing the surface defect , and changing the morphology. Therefore, it is believed that the present work has promising applications in LD lighting and promoting the development of laser display.
研究领域:
材料科学
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光学
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光子学
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激光技术
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照明工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2024
·
IF 2
Yueheng Wang,Ziyu Zhuang,Yanfei Fan,Dandan Gao,Dongdong Li
Ammonium ion is of the same charge as alkali ions and with similar ionic radius as potassium, rubidium, and cesium ions. Solid solutions are very common between ammonium and alkali salts, which is of great interest for understanding the geology, soil, and environment fate of these elements. In this study, the solid–aqueous equilibrium in the NH4Cl + RbCl + H2O and NH4Cl + CsCl + H2O systems was determined at 298.15 K. For each system, two incontinuous solid solutions, i.e. (NH4,Rb)Cl(α) and (Rb,NH4)Cl(β), or (Cs,NH4)Cl(α) and (NH4,Cs)Cl(β), presented, and their composition and structure were studied using Schreinemakers’ wet residues analysis, XRD, and Raman characterization. The equilibrium between these solid solutions and aqueous solutions were well modeled using an integrated solution equilibrium calculator program, in which a Pitzer-Simonson-Clegg model and a subregular model were implemented for describing the nonideality of aqueous phase and solid solution. According to the experimental and thermodynamic modeling results, NH4Cl can dissolve RbCl and CsCl in the solid state (NH4,Rb)Cl(α) or (NH4,Cs)Cl(β) with limited solid solubilities of 0.18 or 0.051 in mole fraction, respectively. RbCl or CsCl can also dissolve NH4Cl in the solid state (Rb,NH4)Cl(β) or (Cs,NH4)Cl(α) with limited solid solubilities of 0.37 and 0.095 in mole fraction, respectively.
研究领域:
化学
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环境科学
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地质学
✓ 已验证
产品关联
DOI
高影响因子
JOM
·
2022
·Vol. 74
·期 5
·1958-1968
·
IF 2.597
Luo Yinbo,He Dongfeng
Indirect carbonation as an efficient CO 2 sequestration strategy has received extensive attention in recent years. This study proposes a two-step leaching indirect carbonation process using NH 4 Cl and CH 3 COOH in order to combine the advantages of the two leaching agents to obtain a better experimental outcome. The experimental results show that NH 4 Cl has a high pH buffering capacity, which can increase the pH of the mixed leachate to an alkaline level. Among the 21 groups of mixed leachate, 17 were alkaline (pH > 7). The mixed leachate has a high Ca 2+ ions carbonation rate under low CH 3 COOH concentration conditions, and the carbonation rate of steel slag with a particle size of < 38 μm can reach 60% when the CH 3 COOH concentration is 0.1 M. SEM imaging showed that the CaCO 3 formed by the reaction exists in a hexagonal calcite crystal form.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2019
·
IF 4.309
Fei Yen,Lei Meng,Tian Gao,Sixia Hu
Different types of magnetism arise mainly from how electrons move and interact with each other. In this work, we show how protons (H+) also exhibit magnetic behavior. We measured the magnetic susceptibility of the ammonium halides and identified pronounced increases at 232, 233, and 243 K for NH4I, NH4Br, and NH4Cl, respectively, all of which coincide with the geometric ordering of their ammonium cations. With extensive literature establishing the fact that the ammonium cations exhibit rotational motion even toward the lowest temperatures, we take into account that the orbital motion of the protons carries a magnetic moment and find it to be larger than that of the paired electrons. Consequently, the structural phase transitions are magnetically driven as the system attempts to lift 8-fold energy degeneracies of the proton orbitals via Jahn–Teller distortions. Our findings identify that NH4+ cations are capable of comprising magnetism which appears to be ubiquitous in ammonia-based molecular solids.
研究领域:
物理学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2018
·Vol. 71
·期 6
·416-421
·
IF 1.059
Ouyang Dong,Zhihong Zhang,Zhenhai Fu,Xiang Li
A new phase-change material (PCM) CaCl2·6H2O + MgCl2·6H2O + NH4Cl was investigated in this paper. MgCl2·6H2O and NH4Cl were mixed with CaCl2·6H2O to obtain CaCl2·6H2O as a eutectic hydrate salt. The results show that the eutectic composition of the PCM is as follows: 90 wt- % CaCl2·6H2O, 6.25 wt- % MgCl2·6H2O and 3.75 wt- % NH4Cl; the undercooling degree is less than 1.5°C when the nucleating agent is 2 wt- % SrCl2·6H2O or 1.5 wt- % Ba(OH)2·8H2O. The phase-change temperature and latent heat are respectively 25.3°C and 144.3 J g−1 when the composition is 90 wt- % CaCl2·6H2O, 6.25 wt- % MgCl2·6H2O, 3.75 wt- %, NH4Cl, with 2 wt- % SrCl2·6H2O as nucleating agent, and 2 wt- % carboxymethyl cellulose as thickener. In addition, when the composition is changed to 90 wt- % CaCl2·6H2O, 6.25 wt- % MgCl2·6H2O, 3.75 wt- % NH4Cl, 1.5 wt- % Ba(OH)2·8H2O and 2 wt- % carboxymethyl cellulose, the phase change temperature and latent heat are 25.2°C and 139.3 J g−1, respectively.
研究领域:
材料科学
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热能存储
·
化学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Yali Zhang,Hongwei Zhang,Fei Xiao
Active aluminum composites are ideal choices for portable hydrogen sources and are playing an increasingly important role in the field of emergency response. The hydrogen production rate from their reaction with water is a key factor determining the practical application effectiveness of these materials. This study thoroughly investigates the catalytic effects of four ammonium salts on the hydrogen production rate of active aluminum composites in water reactions. By incorporating four types of ammonium salts (Al/Bi/NH 4 Cl, Al/Bi/(NH 4 ) 2 C 2 O 4 , Al/Bi/(NH 4 ) 2 CO 3 , and Al/Bi/NH 4 H 2 PO 4 ) along with bismuth into aluminum powder and preparing them through ball milling, four types of active aluminum composites were obtained. A detailed analysis was conducted on the microstructures of these composites and their hydrogen production performance in water reactions. The results show that NH 4 Cl can form a multilayer structure on the surface of Al/Bi/NH 4 Cl, allowing this composite to exhibit the best hydrogen production performance, reaching a maximum hydrogen production rate of 14.4 mL g −1 s −1 and a maximum hydrogen volume of 948 mL g −1 at 45 °C. Additionally, the mechanisms by which different ammonium salts influence the hydrogen production rate of active aluminum composites in water reactions were discussed in detail. The unique multilayer structure of Al/Bi/NH 4 Cl and the excellent solubility of NH 4 Cl contribute to accelerating particle rupture and enhancing the reaction rate. More importantly, H + ions released from the hydrolysis of NH 4 Cl can neutralize OH − produced during the reaction, effectively controlling the pH value of the reaction medium, preventing the deposition of aluminum hydroxide on the aluminum surface, and thus maintaining a larger reaction surface area and continuous reaction activity. The study shows that adjusting the types of ammonium salts can effectively regulate the water reaction kinetics of active aluminum composites.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
Huanyong Li,Zhi Gu,Haiyang Zhang,Heqing Li,Li Fu
Three ZnE (E = Se, Te) single crystals were successfully grown directly from Zn-E (E = Se, Te) system with the assistance of I 2 or NH 4 Cl as the transport agents via a modified chemical vapor transport (CVT) method by avoiding the kinetics limitations of the congruent sublimation of ZnE compound. As-grown ZnE crystals exhibit different crystalline appearance due to various growth conditions. The structure, growth habit and morphologies of as-grown ZnE crystals are investigated by XRD , RO-XRD, SEM and optic microscope. ZnE crystals with NH 4 Cl transport agent look like the platelets with an interesting growth habit, while ZnE crystal with I 2 transport agent has high crystalline quality with a conical shape. Contrasting investigation between different growth results offers us an opportunity to understand the vapor-free-growth mechanism of ZnE crystals in closed-space CVT system, indicating that the free-growth habit of ZnE crystals depends on the growth parameters, which can be essentially attributed to their growth mechanism and the main vapor–solid reactions on the interfaces.
研究领域:
材料科学
·
晶体生长
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2026
·
IF 4.4
Jiang Meng,Jiayang Wu,Xiaoning Lu,Mengchen Zeng,Shunxu Yang,Junling Yang,Shuping Li,Meizi Zhou,Wanxun Li,Mingchao Zhu,Guangcan Zhu
NH₄Cl gas template creates hierarchically porous g-C₃N₄ via one-step microwave synthesis. • 10 g-GCN achieves 2.35× increased surface area (26.09 m 2 g −1 ) and 88% CFS degradation. • Porous structure shortens charge migration paths and enhances mass transfer. • O₂ − dominates the degradation; ·OH plays a larger auxiliary role than in etching systems. • ECOSAR warns of high-toxicity intermediates requiring complete mineralisation. Graphitic carbon nitride (g-C 3 N 4 ) is a promising metal-free photocatalyst for water purification, but its low surface area and poor mass transfer in densely stacked layers limit practical performance. Herein, a microwave-assisted gas-template strategy using ammonium chloride (NH 4 Cl) was employed to prepare hierarchically porous g-C 3 N 4 nanosheets (GCN). During microwave-driven polycondensation of melamine, NH 4 Cl decomposed in situ to release NH 3 and HCl gases, which simultaneously disrupted the lamellar stacking and generated abundant mesopores without requiring a separate solid-template removal step. The optimised 10 g-GCN exhibited a specific surface area of 26.09 m 2 g −1 , 2.35 times higher than pristine g-C 3 N 4 , and a pore volume of 0.190 cm3 g-1. Under visible-light irradiation, 10 g-GCN degraded 88% of cefotaxime sodium within 60 min, with an apparent pseudo-first-order rate constant of 0.03242 min −1 , 4.16 times that of bulk g-C 3 N 4 . The enhanced activity is correlated with the porous nanosheet architecture, which is associated with shortened charge-migration distances, enhanced pollutant diffusion, and increased accessibility of active sites. Radical-trapping experiments confirmed superoxide radicals (·O 2 − ) as the dominant reactive species, while hydroxyl radicals (·OH) may be generated as a minor supplementary species through the electron-driven cascade reduction of O 2 . The degradation efficiency decreased from 88% to 79% after five cycles (approximately 90% of the initial efficiency retained), and the catalyst showed broad-spectrum degradation towards cephalosporin and non-cephalosporin antibiotics. LC-MS identified pathways including de-esterification, side-chain cleavage, beta-lactam ring opening, and fragmentation towards mineralisation. TOC confirmed 28.0% mineralisation, while ECOSAR indicated that some intermediates may still exhibit elevated aquatic toxicity, highlighting the need for sufficient mineralisation in practical treatment scenarios.
✓ 已验证
DOI
高影响因子
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
·
2026
·
IF 1.3
Wei Li,Bangfu Huang,Yihang Shi,Kui Zheng
To investigate the effects of NH4F and NH4Cl on the crystallization process of ammonium sulfate, experiments were designed using response surface methodology. Combined with the evaporation crystallization method, the study explored the combined effects of NH4F and NH4Cl, stirring rate, and pH on crystallization. The results indicate that the synergistic ratio of NH4F to NH4Cl and stirring rate significantly influence the crystallization yield of ammonium sulfate, with the order of effect intensity being synergistic ratio of NH4F to NH4Cl > stirring rate > pH value. The interaction between the synergistic ratio and stirring rate significantly affects the crystallization yield. All three factors significantly influence the average particle size, with their effects following the same pattern as crystallization quantity. Furthermore, the synergistic interaction between crystallization quantity and pH value significantly impacts particle size. The model predicted optimal process parameters as follows: NH4F:NH4Cl = 3:1, stirring speed = 200 rpm, pH = 4.74. Under these conditions, the theoretical crystallization yield was 57.39 g with an average particle size of 1.25 mm. Validation experiments showed that the actual crystallization yield under these conditions was 58.47 g with an average particle size of 1.23 mm, indicating a small error margin.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yiwen Wang,Qinliang Jiang,Jianxin Li,Zhenyu Cui,Li Wu,Shuanglin Gui,Jiaqi Fu
During the rare earth refining process, high concentrations of ammonia nitrogen generated from the ammoniation reaction are significant pollutants in wastewater. The low cost and energy efficiency of membrane absorption technology have garnered widespread attention. This study optimized the key operating parameters of the membrane absorption process. A pretreatment (alkaline adjustment and ultrafiltration (UF))- membrane absorption integrated process was used to successfully remove and recover ammonia nitrogen from actual rare earth smelting wastewater. The pre-treatment process effectively removed large particulate matter from the water, reducing turbidity from 1.60 NTU to 0.60 NTU. Additionally, the removal rates for metal ions such as Fe, and Mg exceeded 98%. Under the optimized membrane absorption parameter conditions (when the pH of the feed solution is between 11.50 and 12.00, and the absorbent solution is between 1.00 and 1.30, maintaining efficient absorption conditions with a feed solution flow rate of 1.13 L/h and an absorbent flow rate of 0.75 L/h), the purification/removal of ammonia nitrogen from the wastewater was carried out. The ammonia concentration in the treated water was reduced to just 0.02 mg/L, achieving a removal efficiency of 99.99%, fully meeting the discharge standards for ammonia nitrogen in water. The chemical oxygen demand (COD) also decreased to 134 mg/L, with a removal efficiency of 61.71%. Furthermore, an ammonium chloride solution (1850 mg/L) was obtained from the absorption side, with the ammonium chloride content in the solute reaching 86.52%. This integrated treatment process offers an efficient method for the selective separation and recovery of ammonia nitrogen resources from rare earth refining wastewater.
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9.1
Jianguo Sun,Qian Liu,Wenqi Zhong,Yun Xu,Jingxin Xu,Ziqun Wang
Solid adsorption is a promising approach for CO 2 capture owing to its low energy consumption. N doping can enhance the CO 2 adsorption capacity of porous carbon adsorbents. Conventional doping strategies rely on exogenous N additives (e.g., urea or melamine), and often suffer from low doping efficiency and potential environmental risks. Crayfish shells are attractive precursors for N-rich porous carbons owing to high N content, but their utilization is hindered by the high CaCO 3 content and the poor thermal stability of N species. Herein, we report an NH 4 Cl-assisted pyrolysis strategy that simultaneously enables in situ CaCO 3 removal, initial pore formation, and reconstruction of intrinsic N species into thermally stable N configurations. The prepared porous carbon contains 9.65 at.% N and achieves a CO 2 uptake of 4.44 mmol/g at 25 °C and 1 bar, with an isosteric heat of adsorption (Q st ) of 22.11–27.84 kJ/mol. Owing to its relatively low Q st , the adsorbent could be regenerated below 60 °C under an N 2 purge and retained 97.6% of its initial adsorption capacity after 15 cycles. The dynamic CO 2 /N 2 separation performance and the effect of H 2 O were evaluated under dry and wet flue gas conditions. Density functional theory (DFT) calculations and experimental results indicated that H 2 O played a dual role in CO 2 adsorption: competitive adsorption at N sites and pore blocking hindered CO 2 diffusion, whereas H 2 O-induced redistribution of the local electrostatic potential strengthened subsequent CO 2 adsorption. This work provides a feasible route for utilizing crayfish shell waste and developing intrinsically N-doped porous carbons for wet flue gas CO 2 capture.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 1
·122-135
·
IF 3.094
Jingkun Xu,Zunlan Hu,Yao Han,Di An,Zhipeng Xie
In the present work, high-quality MgSiN 2 powders were prepared by a combustion synthesis method, based on Mg-Si 3 N 4 -N 2 system. The effects of additive content (NH 4 Cl or NH 4 F) and N 2 pressure on phase composition and crystal morphology of products were investigated. The results suggested that both NH 4 Cl and NH 4 F additives alleviated agglomeration and decreased the grain size of MgSiN 2 . In addition, NH 4 Cl did not result in the formation of an extra impurity, while MgF 2 residue was found when NH 4 F was introduced. Therefore, NH 4 Cl additive was considered as a better choice for the preparation of MgSiN 2 powders in comparison with NH 4 F additive. According to the observation of some MgSiN 2 whiskers and notably increased Si content under low N 2 pressure, the pressure of N 2 over 0.5 MPa was essential to have a complete reaction in the present work. Finally, MgSiN 2 -Si 3 N 4 composite powders with quasi-spherical morphology were prepared by adding excessive Si 3 N 4 and NH 4 Cl additive in reactant. The formation and growth mechanism of MgSiN 2 grains was reasonably speculated based on the experimental results. Because of the remarkable merits, the as-prepared Si 3 N 4 -MgSiN 2 composite powders showed great potential for alternative sintering aid in the sintering of Si 3 N 4 -based ceramics.
研究领域:
材料科学
·
陶瓷
·
合成方法
✓ 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）