CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Mei Jiang,Lin Zhu,Qian Zhao,Guangyuan Chen,Zeru Wang,Jingjing Zhang,Ling Zhang,Jiehong Lei,Tao Duan
Effective capture of radioactive iodine in spent fuel reprocessing is an urgent problem to be solved. In this study, we reported a novel fluoride modified bismuth sulfide supported NaY zeolite material (NaY-NH 4 F-Bi 2 S 3 ), prepared by hydrothermal method. The zeolite with a hydrophobic skeleton was obtained by etching with NH 4 F solution. The adsorption mechanism generally follows preferential iodine enrichment in NaY zeolite microporous channels and is subsequently immobilized by loaded bismuth sulfide sites on NaY zeolite. Under the combination of physical and chemosorption, the sorption capacity of NaY-NH 4 F-Bi 2 S 3 reaches 491 mg/g, which is much higher than that of bare NaY zeolite. The excellent thermal stability and radiation stability greatly enhance its iodine capture performance under harsh conditions. The comprehensive characteristics of high cost-effectiveness, low toxicity, good radiation resistance, and good thermal stability make it have potential applications in the capture, immobilization and storage of radioactive gaseous iodine during spent fuel reprocessing.
研究领域:
核科学与工程
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Applied Sciences-Basel
·
2020
·Vol. 10
·期 3
·1021
·
IF 2.474
Yonglei Zheng,Yikai Li,He Wang,Siheng Chen,Xiangxin Guo,Sheng Xu,Zhongyu Cai
We report a novel method to fabricate lithium-ion batteries cathodes with the NH4F pretreatment. In this study, NH4F-pretreated Li1.25Ni0.20Fe0.13Co0.33Mn0.33O2hollow nano-micro hierarchical microspheres were synthesized for use as cathode materials. The X-ray diffraction patterns of NH4F-pretreated Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2were analyzed with the RIETAN-FP software program, and the results showed that the samples possess a layered α-NaFeO2structure. The effects of pretreatment with NH4F on the electrochemical performance of the pristine material were evaluated through charge/discharge cycling, the rate performance, and electrochemical impedance spectroscopy (EIS). Pretreatment with NH4F significantly improved the discharge capacities and coulombic efficiencies of Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2in the first cycle and during subsequent electrochemical cycling. The sample pretreated with an appropriate amount of NH4F (NFCM 90) showed the highest discharge capacity (209.1 mA h g−1) and capacity retention (85.2% for 50 cycles at 0.1 C). The EIS results showed that the resistance of the NFCM 90 sample (76.32 Ω) is lower than that of the pristine one (206.2 Ω).
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
ORGANIC ELECTRONICS
·
2020
·
IF 3.31
Shuo Wang,Yu Zhu,Chengyan Wang,Ruixin Ma
Inverted perovskite solar cells with NiO x hole transport layer (HTL) have attracted abundant attention due to low-cost fabrication and high device-efficiency. However, the further development of NiO x -based inverted perovskite solar cells (PSCs) would be restricted by the unsatisfactory electrical properties in pristine NiO x and the non-ideal charge transfer between perovskite and NiO x . In this work, a facile and effective method was designed to regulate the electronic property of NiO x HTL and make an alteration to the interface between the perovskite and NiO x . NH 4 F was used as an interfacial modifier to enhance the charge transfer between the perovskite layer and NiOx. The NiO x -F layer was generated with high transmittance and low trap density . Besides, the power conversion efficiency of the device was improved from 17.17% to 18.94% with the improvement of short-circuit current (J sc ) by using the structure of ITO/NiO x /NH 4 F/MAPbI 3 /PCBM/BCP/Ag. Finally, the device with NH 4 F exhibited better stored stability in the dry condition compared with the control device.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Youbing Zhu,Xiangfei Ding,Jian Chen,Hongyan Wang,Hui Wang
One-dimensional microporous zeolite, EU-1, has tighter restriction for bulky intermediates, exhibiting more favorable selectivity of propylene than ZSM-5 in catalytic cracking. However, the diffusion limitation accelerates coke generation, passivates acid sites and deactivates the zeolite. In this study, a strategy was proposed to etch amorphous species between EU-1 nanocrystals using NH 4 F solution to improve the diffusion property. It was found that the etching process occurred on the crystal surface and mesopores were introduced. Catalytic performance evaluation in n-hexane cracking demonstrated that the maximum propylene selectivity over parent EU-1 was 33.6 wt% ( vs . 5.7 wt% for ZSM-5). The n-hexane conversion was increased by 24 wt% over EU-1 etched in 20 wt% NH 4 F solution. Moreover, the introduction of mesopores provides accommodation space for coke. This study developed hierarchical EU-1 zeolite with favorable diffusion ability and reported a feasible strategy to improve the catalytic performance of EU-1 for propylene production.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
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IF 5.116
Ziqiu Ren,Na Wang,Menghua Zhu,Xin Li,Jingyao Qi
The simple assembling process and lower manufacturing cost are crucial for wide application of perovskite solar cells. In this work, we report an efficient interface passivation strategy for preparing high-performance planar perovskite solar cells, which does not require well-controlled moisture and oxygen atmosphere. A NH 4 F solution-based additive is introduced to passivated TiO 2 electron transfer layer, which offers reduction of oxygen-induced defects and residual surface hydroxyl groups , and lower trap state level. Using a typical planar structure of FTO/NH 4 F-TiO 2 /CH 3 NH 3 PbI 3 /Spiro-OMeTAD/Au, the champion device achieves a power conversion efficiency of 15.61%. After 28-day durability test, the device with NH 4 F-treated TiO 2 storing in air without any encapsulation exhibits a little efficiency loss (<10%). Our work demonstrates a generic approach to develop air-processed efficient planar perovskite solar cells by interface engineering for future commercialization.
研究领域:
材料科学
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太阳能
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电气工程
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化学
✓ 已验证
产品关联
DOI
高影响因子
Inorganics
·
2025
·Vol. 13
·期 8
·272
·
IF 3
Juan Du,Xiang Wan,Caixiong Song,Kangsheng Wu,Wenbing Yang,Beiye Liu,Qi Yang,Jingjing Fang,Ayesha Razzaq
Crystal twinning, a common growth phenomenon, can substantially affect material performance in fields such as semiconductors, nonlinear optics, and drug development, yet its elimination during crystallization is challenging. This study presents a method for the controlled synthesis of ZSM-5 zeolite as either single crystals or twinned crystals using kaolin as the primary raw material. The method leverages the etching effect of ammonium fluoride (NH4F) on the aluminosilicate structure derived from pre-treated kaolin. By adjusting the concentrations of NH4F and the structure-directing agent tetrapropylammonium bromide (TPABr), pure ZSM-5 single crystals and twinned crystals were selectively synthesized. Conventionally, NH4F is employed to introduce defects into zeolite structures. In contrast, this work demonstrates its utility in controlling crystal habit. The synthesis utilizes kaolin, an abundant and low-cost aluminosilicate mineral, to provide the entire aluminum source and a portion of the silicon source, offering an economical alternative to expensive precursors like aluminum isopropoxide. The resulting single and twinned crystals exhibited high crystallinity, demonstrating the viability of using natural minerals to produce high-quality zeolites. The physical and chemical properties of the kaolin-derived ZSM-5 were characterized and compared to those of ZSM-5 synthesized from conventional chemical reagents. A growth mechanism for the formation of single and twinned crystals is also proposed.
研究领域:
材料科学
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晶体学
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无机化学
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纳米技术
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化学合成
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2017
·Vol. 4
·期 4
·045006
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IF 1.068
Hongtao Cui,Li Wang,Min Shi,Yanhong Li
In this work, lepidocrocite (γ-FeOOH) nanobundles were prepared by a facile NH4F assisted epoxide precipitation route. The reactions between epoxide and [Fe(H2O)6]2+ promoted the hydrolysis and condensation of [Fe(H2O)6]2+, resulting in the formation of iron oxyhydroxide. After calcination of γ-FeOOH nanobundles at 400 °C, the produced α-Fe2O3 still kept the bundle morphology. Due to the unique chemistry of epoxide, the morphology and phase of iron oxide polymorph nanoparticles (goethite, akaganeite, lepidocrocite, magnetite) were well-controlled through controlling reaction conditions such as Fe2+ concentration, NH4F additive and reaction temperature. It is particularly interesting that NH4F working as phase controlling agent is able to control the phase development of iron oxyhydroxides. This phase control effect of NH4F is attributed to the promoted reaction rate of epoxide originating from the higher electronegativity of fluoride ions than chloride ions. Based on the results in this work and our other preliminary works, it is considered that this route can be used as a general strategy for controlling the morphology and phase of transition element compounds.
研究领域:
材料科学
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化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2021
·
IF 3.739
Han Wang,Shulan Wang,Jingqiao Zhang,Han Wang,Hui Li,Yi Zhao
Several mesostructured cellular foams (MCFs) were prepared and modified for NO adsorption. TMB, NH 4 F and n -heptane were used as swelling agents, and APTES was used as the modified agent. The morphological structure, chemical composition, thermostability were tested to study the effects of the preparation process on the characterizations of materials. NO adsorption ability of the materials were studied and discussed. NH 4 F and n -heptane had better pore swelling effects compared to TMB, however adding TMB together with NH 4 F and n -heptane could not enlarge the pore structure further. The MCFs materials could keep steady below 800 °C, but after grafting APTES on the surface of the materials, the thermogravimetric curve of materials began to decrease at 300 °C. The materials using NH 4 F and n -heptane as the swelling agents, and modified by APTES had better NO adsorption ability, and the selectivity of the materials were decided by the molecular polarity of the adsorbates. After the modification, the hydrophobic effect of the samples could increase because of the alkyl groups in APTES. The adsorption capacity of the materials could keep steady for ten times without the coexisting component, H 2 O, CO 2 and SO 2 all had negative effects on the regeneration of the materials.
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
IONICS
·
2024
·Vol. 30
·期 8
·4479-4486
·
IF 2.4
Tang Anping,Chen Juedong,Xu Guorong,Song Haishen,Wang Jinglun,Chen Hezhang
Non-intercalation cathode materials based on nanocomposites of lithium fluoride and Li-free transition metal compounds have drawn attention as materials for fabricating the cathode of lithium ion batteries owing to their high theoretical specific capacities and high redox voltages. In the present study, a nanocomposite of MnO-LiF was in situ synthesized by a quick annealing at 500 °C for just 5 min using a mixture of ammonium fluoride, manganese acetate, and lithium acetate as precursor. The synthesized composite is investigated by X-ray diffraction, scanning electron microscopy, nitrogen sorption, and charge-discharge measurements. As a lithium-ion battery cathode, it delivers respectively an initial discharge-specific capacity of 170 mAh g −1 and a discharge-specific capacity of 137 mAh g −1 in the 50th cycle at a current rate of C/20, which is equivalent to a moderate capacity retention rate of 80.6%. The novel synthesis approach proposed offers access to electrochemically active composites of lithium fluoride and Li-free transition metal oxides.
研究领域:
材料科学
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电化学
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纳米复合材料
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能源存储
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锂离子电池
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Tingting Xu,Liu Yang,Jing Li,Natalia Usoltseva,Vladimir An,Xin Jin,Cai Zhang,Xinglai Zhang,Baodan Liu
Developing non-noble metal catalysts with superior catalytic activity and excellent durability is critically essential to promote electrochemical water splitting for hydrogen production. Morphology control as a promising and effective strategy is widely implemented to change the surface atomic coordination and thus enhance the intrinsic catalytic performance of current electrocatalysts. Herein, a series of cobalt phosphide (CoP) electrocatalysts with tunable morphologies of nanosheets, nanowires, nanorods, and nanoblocks have been prepared for the enhanced hydrogen evolution reaction (HER) by only adjusting the amount of ammonium fluoride (NH4F) in the hydrothermal process. Benefiting from the large active area, high surface activity, and favorable ion and gas diffusion channels, the clustered CoP nanorods obtained at a concentration of 0.15 M NH4F show the best HER performance with only an overpotential of 71 mV at a current density of 10 mA cm–2 and a low Tafel slope of 60.75 mV dec–1 in 1 M KOH. After 3000 CV cycles and 24 h durability tests, there is only a very slight degradation of performance owing to its outstanding stability and robust substrate adhesion.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2025
·
IF 4.9
Chunyu Wu,Zhiqiang Wei,Meijie Ding,Meipan Zhou,Yanxia He,Ke Huang,Qingpan Liu,Jinglong Bai
Transition metal phosphides are regarded as ideal electrode materials for high energy density supercapacitors due to their high theoretical specific capacitance and multi-electron redox properties, but they still face challenges such as low utilization of active sites, high resistance to ion diffusion, and structural collapse during cycling. In this study, we propose a three-dimensional nickel-cobalt phosphide nanosheet array design strategy based on ammonium fluoride (NH 4 F) modulation, and vertically aligned three-dimensional porous nickel-cobalt-phosphide nanosheet arrays (F5–NiCoP/NF) were constructed in-situ on nickel foam substrates by a template-free hydrothermal-phosphorization two-step method. Its superior electrochemical performance stems from bimetallic synergy and the high conductivity of the phosphide. Vertical nanosheet arrays build a three-dimensional conductive network to reduce ion diffusion resistance, and abundant pores significantly accelerate charge transport and expose abundant electroactive sites. Notably, this approach simultaneously simplifies the preparation process and reduces the cost. Benefitted from these merits, the F5–NiCoP/NF electrode achieves a high specific capacitance of 3244 F g −1 at a current density of 1 A g −1 , a capacity retention of 75.69 % at a high multiplicity of 10 A g −1 , and retains 81.44 % of its initial capacity after 10,000 cycles. The assembled asymmetric supercapacitor F5–NiCoP/NF//AC exhibits an energy density of 48.37 Wh kg −1 and a power density of 800.04 W kg −1 .
研究领域:
材料科学
·
电化学
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纳米技术
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储能
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Bowen Xu,Mengshan Deng,Kehang Lin,Yuexia Wang,Xinqing Lu,Rui Ma,Yanghe Fu,Weidong Zhu
Ti-Beta zeotypes, possessing three-dimensional 12-membered ring pore-opening channels, have shown some superior catalytic performance in the epoxidation of bulky cycloalkenes with hydrogen peroxide (H 2 O 2 ) in comparison with other titanosilicate zeotypes. However, some further improvement on the catalytic activity and selectivity of Ti-Beta zeotypes is still demanded for the industrialization of cycloalkenes epoxidation. In the present work, the catalytic performance of Ti-Beta in cyclohexene epoxidation was significantly improved via the transformation of their closed Ti(OSi) 4 sites into the open Ti(OSi) 3 OH ones by a simple NH 4 F treatment. Based on the extensive characterization results, it is found that the NH 4 F-treated Ti-Beta zeotypes with open Ti(OSi) 3 OH sites, named OH-Ti-Beta, possess a stronger Lewis acidity that is favorable to the production of cyclohexene oxide (CHO) from the epoxidation of cyclohexene with H 2 O 2 , compared to the parent Ti-Beta with closed Ti(OSi) 4 sites. Moreover, OH-Ti-Beta catalysts are reusable after the calcination of the deactivated zeotypes. Hence, it is expected that the current developed NH 4 F treatment can obtain efficient OH-Ti-Beta catalysts industrially applied in cyclohexene epoxidation.
研究领域:
催化化学
·
材料科学
✓ 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）