Progress in Natural Science-Materials International
·
2018
·Vol. 28
·期 4
·529-533
·
IF 2.572
Zhenmin Ding,Yufei Ma,Dandan Peng,Lu Zhang,Yumeng Zhao,Yuan Li,Shumin Han
In this work, LiBH 4 –20 wt% PP composite was prepared by ball-milling with as-synthesized hierarchical pyrolysis polyaniline (PP) and LiBH 4 , and the hydrogen sorption performance as well as catalytic mechanism of the composite was studied. It is found that the onset desorption temperature of the composite decreases to 75 °C, almost 235 °C lower than that of the milled LiBH 4 . Moreover, the composite could release 4.1 wt% H 2 and rehydrogenate a total of 4.4 wt% H 2 when the temperature raiseds up to 400 °C, showing an outstanding reversibility, which even 3.9 wt% H 2 can be kept after five cycles. Through scanning electron microscopy (SEM) observation and X-ray diffraction (XRD) analysis, we found that the PP surface forms some nanoholes after hydrogenation-dehydrogenation cycles, which leads to the confinement of some LiBH 4 in the PP nanoporous structure, therefore, the hydrogen sorption kinetics and reversibility are significantly enhanced. In addition, we also found the oxygenic groups of the PP can react with LiBH 4 forming LiBO 2 and Li 3 BO 3 , where the containing Li–B–O bonds loaded in the porous structure of the PP catalyze the hydrogenation reaction of LiBH 4 .
研究领域:
材料科学
·
能源化学
·
纳米材料
·
固态储氢
·
催化化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 19
·26869-26876
·
IF 4.527
Shao-Min Lin,Ya-Ling Yu,Ming-Feng Zhong,Huan Yang,Chen-Yang Zhang,Zhi-Jie Zhang,Wei Xu,Jiong-Yan Xie,Yu-Chun Qiu
Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al 2 O 3 ), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al 2 O 3 was activated by oxalic acid . XRD , 27 Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al 2 O 3 decreased to 1029 °C for oxalic acid activated γ-Al 2 O 3 , and the α-fraction was 100% for activated γ-Al 2 O 3 at 1300 °C. After oxalic acid activation , the diffraction peak intensity of γ-Al 2 O 3 decreased significantly; the results of 27 Al-MAS-NMR suggested that octahedral [AlO 6 ] in γ-Al 2 O 3 was easier than tetrahedral [AlO 4 ] to be attacked by oxalic acid , and the formation of pentavalent [AlO 5 ] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al 2 O 3 . The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al 2 O 3 and extracted Al as three complexes of [Al(C 2 O 4 )] + , [Al(C 2 O 4 ) 2 ] - and [Al(C 2 O 4 ) 3 ] 3- . Oxalic acid activated γ - Al 2 O 3 with a lower phase transformation temperature has broad application prospects in the alumina industry.
研究领域:
材料化学
·
无机化学
·
固态化学
·
工业催化
·
陶瓷材料
✓ 已验证
DOI
高影响因子
IRANIAN POLYMER JOURNAL
·
2019
·Vol. 28
·期 2
·157-166
·
IF 1.707
Zhang Guangyan,Zhou Jun,Wang Peng
A novel cross-linkable polyaspartamide derivative-containing cinnamoyl pendant groups, P(HPA-Az)-CA, was designed and synthesized in this study. Chemical structures of the obtained polymers were confirmed by FTIR, UV, and 1 H NMR techniques. The transmittance measurement results showed that the prepared polymer P(HPA-Az)-CA displayed temperature and pH dual stimuli-responsive behaviors. The cloud point of P(HPA-Az)-CA could be tuned just by adjusting the introduced percentage of hydrophobic moieties or the pH of polymer aqueous solution. The effect of pH on the cloud point of P(HPA-Az)-CA was investigated by zeta potential, and the results showed that it may be related to the weakened electrostatic repulsion caused by decreased zeta potential with pH decreasing. Diamines (ethylenediamine or cystamine) were adopted to prepare cross-linked micelles using the mixture of P(HPA-Az)-CA aqueous solution and diamines just by one-step heating method. The cross-linked micelles were stable, even when the environmental temperature was below the cloud point of P(HPA-Az)-CA. The cross-linking mechanism between the diamines and α,β-unsaturated carbonyl moieties of P(HPA-Az)-CA was confirmed by 1 H NMR. In addition, the micelles cross-linked with cystamine could be disrupted in the presence of 10 mM glutathione. According to the results, the obtained polyaspartamide derivative P(HPA-Az)-CA may be a potential for facilitating drug loading.
研究领域:
高分子化学
·
药物传递系统
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2019
·Vol. 230
·期 2
·41
·
IF 1.774
Wang Wanfeng,Liang Fang,Guo Yanling,Wu Ruijie,Pan Feng,Jin Caixia,Wang Jun
Since nitrosamine disinfection by products is highly carcinogenic, they have attracted considerable attention due to their increased presence in ambient waterways and potable water supplies. For the present study, the potential formation of nitrosamines from corresponding precursor secondary amines during ozonation was investigated. The results revealed that five nitrosamines were observed during the ozonation of their corresponding secondary amines. The molar yields initially increased and then decreased with longer contact times and higher ozone doses. These phenomena indicated that ozone not only promoted nitrosamine formation but also degraded the formed nitrosamines. High pH had a positive influence on nitrosamine formation at room temperature. Further, coexisting substances including nitrate, nitrite, humic acid, and tert-butanol inhibited the generation of nitrosamines due to hydroxyl radical (·OH) competition and scavengers, whereas in the presence of hydroxylamine, nitrosamine formation increased considerably without ozone due to its capacity for independent formation between secondary amines and hydroxylamine. Further, the generation of nitrosamines from secondary amines was primarily attributed to O 3 and ·OH oxidation, which was produced through the decomposition of ozone. The transformation pathways were mainly comprised of the indirect routes between the O 3 /·OH intermediates. The findings of this study were helpful toward expanding the knowledge of nitrosamine formation during the corresponding precursor secondary amine ozonation process.
研究领域:
环境科学
·
水处理化学
·
污染物转化
·
消毒副产物
·
氧化过程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Dan Yang,Qingfeng Guo,Libing Liao,Yidi Zhang,Lefu Mei,Haikun Liu
In this paper, K 3 ScF 6 :Er 3+ ,Yb 3+ up-conversion luminescent materials with cryolite structure were synthesized via solid-state method. The X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL) under the excitation of a 980 nm laser with different power density were used to investigate the phase structure, elemental composition , and up-conversion luminescence properties of K 3 ScF 6 :Er 3+ ,Yb 3+ . The quenching concentrations of Yb 3+ and Er 3+ were confirmed to 0.15 and 0.05 (mol concentration) in this system, respectively. Upon 980 nm excitation, the K 3 ScF 6 :Er 3+ ,Yb 3+ showed a typical transition of Er 3+ which contains two main bands in the visible region that green and red. According to the fitting result of the pump power dependence of up-conversion intensity, all the green and red up-conversion emission of K 3 ScF 6 :0.05Er 3+ ,0.15 Yb 3+ belong to the two-photon process. To better understand the origin of radiation and energy transfer mechanism of the red and green up-conversion, the possible mechanism and electron transition process were also discussed.
研究领域:
材料科学
·
无机化学
·
光功能材料
·
固体化学
·
发光物理
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 9
·e5082
·
IF 3.259
Dongmei He,Li Zeng,Guiqing Zhang,Qinggang Li,Wenjuan Guan,Zuoying Cao,Shengxi Wu
A new compound, α-aminophosphonate derivative containing pyridine ring (PPDE), was designed and synthesized as an extractant for the separation of nickel from metal impurities. Over 94.5% of Ni (II) extraction from sulfuric acid solution was achieved by using PPDE with an equilibrium pH of 4.02. Meanwhile, high separation coefficients of 23.8 for Ni to Co, 84.9 for Ni to Mn, 254.1 for Ni to Ca and 696.7 for Ni to Mg, respectively, were obtained. It was noted that PPDE exhibited an excellent regenerability, and the extraction of Ni with the recycled organic phase ranged from 92.5% to 93.9% during six circulations. The extracted nickel complex was determined as [Ni (PPDE) 2 (DNNSA − ) 2 (H 2 O) 4 ], which was supported by the data obtained from Fourier transform-infrared, UV–Vis and electrospray ionization-mass spectrometry spectra.
研究领域:
无机化学
·
湿法冶金
·
分离科学
·
配位化学
·
环境化学
·
资源回收
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 18
·8566-8577
·
IF 3.3
Tingting Tang,Bo Jin,Ping Zhao
Aromatic nitro compounds are the main components of explosives. They are not only explosive and dangerous but also have high toxicity and high stability in the human body, soil, and water resources, destroying the ecological environment. Herein, a simple hydrothermal method is used to successfully prepare layered MIL-100 (Fe). A series of aromatic nitro compounds including p-nitrophenol (PNP), nitrobenzene (NB), dinitrotoluene (2,4-DNT), dinitrophenol (2,4-DNP), and 2,4,6-trinitrophenol (2,4,6-TNP) were degraded by the photo-Fenton method. The MIL-100 (Fe) photo-Fenton agent can almost completely degrade PNP within 2 min. Similarly, it has a good degradation effect on other pollutants. Finally, the mechanism of the photo-Fenton reaction was discussed by product analysis and free radical capture experiments after the photochemical reaction. This study demonstrates the potential application value of MIL-100 (Fe) as a photo-Fenton reagent to degrade nitroaromatic explosives.
研究领域:
环境化学
·
材料科学
·
催化化学
·
环境污染与控制
·
应用化学
✓ 已验证
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Yu-hong Qin,Min-min Feng,Zi-bing Zhao,Stanislav V. Vassilev,Jie Feng,Christina G. Vassileva,Wen-ying Li
The ash fusion process of Jincheng anthracite ash, rice straw ash and coal-biomass ashes with different rice straw ash addition ratios during co-gasification under CO 2 atmosphere was elucidated by the ash fusion test, chemical analyses, optical heating stage microscopy (OHSM), X-ray diffraction and scanning electron microscopy equipped with energy-dispersive X-ray analyzer. Results showed that the initial sintering and initial melting temperatures of coal-biomass ashes observed by OHSM decreased with the addition of rice straw ash. The deformation temperatures determined by the ash fusion test were close to the initial melting temperatures. The biomass ash addition to coal ash introduced excessive amounts of alkaline compounds in the ash mixtures that led to lower initial temperatures of liquid phase formation. The ash fusion behavior of coal-biomass ashes with a rice straw ash addition ≤3 wt% was similar to that of coal ash and fits to the “softening-melting” ash fusion mechanism. In contrast, the ash fusion behavior of coal-biomass ashes with a greater addition of rice straw ash (>3 wt%) experienced dramatic changes at lower temperature and fits to the ‘‘melting-dissolution’’ ash fusion mechanism.
研究领域:
燃料化学
·
能源工程
·
热化学转化
·
燃烧学
·
灰化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 49
·期 11
·18776-18785
·
IF 5.2
Jiaxu Cheng,Siwei Jiang,Jiahong Fan,Jun Yao,Ning Du,Xue Li,Ding Wang,Peng Dong,Zhongren Zhou,Yingjie Zhang
Molten salt electrolytic synthesis of silicon is identified as a potential industry method due to its thorough deoxidization of oxide and short-flow synthetic progress. However, figuring out a more efficient and sustainable strategy for the increase of the reduction process as well as the control of product morphology still needs endless research. In this study, benefiting from the high electrical conductivity of metallic silver and the easy separation of silver from silver-silicon alloys during the electrolysis of SiO 2 , metallic silver was introduced to electric-catalyze the production of silicon. Firstly, metallic silver was introduced into the silica matrix by a simple silver mirror reaction. Secondly, the mixed Ag\SiO 2 precursor was located at the cathode for molten salt electrolysis . Finally, silicon nanowires were herein achieved in molten NaCl–CaCl 2 . Mechanisms of metal Ag played during the electric-polarization process of silica and the electrochemical nucleation of silicon were further analyzed by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Field-Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectra . The results demonstrate that Ag helps construct Si nanowires via a classic Ag-Si binary alloy-droplet process and provided quantitative guidance for the large-yield production of silicon nanowires via adding 0.08–0.17 g Ag versus 1 g SiO 2 , controlling the temperature at 850–900 °C and electrolysis voltage at 2.6–2.8 V (2.6V at first 1 h and 2.8V at last 5 h). The synthesized silicon nanowires present two types of linear structures based on two three-phase interlines (3PIs) models and a streamed long-straight nanowire is observed.
研究领域:
材料科学
·
纳米科技
·
电化学
·
无机化学
·
能源材料
·
半导体材料
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2019
·Vol. 2019
·期 1
·5290496
·
IF 2.233
Zhenzhu Yu,Fei Nan,Lu Su,Shaofei Zhang,Yan He
Intercalation and exfoliation are key steps in the preparation of graphene by thermal exfoliation, and they determine the quality of the final product. Therefore, it is important to explore the influence of intercalation agents on the intercalation and exfoliation of graphite. In this article, ammonium bicarbonate is intercalated into graphite with different degrees of oxidation to form a graphite intercalation compound (GIC) by means of ultrasound and stirring. Then, they are exfoliated by being heated at high temperatures. After ammonium bicarbonate intercalation and heating treatment, XRD, TG, and BET show that the intercalation and exfoliation effect of graphite oxide (GO) is better than that of graphite (G) and expanded graphite (EG). The intercalation mechanism is that the ammonia molecule in ammonium bicarbonate solution contains a wedge-shaped structure and active point, which provides empty orbits for graphite electrons and forms edge intercalation through physical interaction at the same time.
研究领域:
材料科学
·
纳米材料
·
物理化学
·
碳材料
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 40
·21265-21272
·
IF 11.301
Lei Gao,Hao Zhang,Yuechao Wang,Shuai Li,Ruo Zhao,Yonggang Wang,Song Gao,Lunhua He,Hai-Feng Song,Ruqiang Zou,Yusheng Zhao
Sodium-rich antiperovskite (NaRAP) ionic conductors have been considered promising inorganic electrolytes for all-solid-state sodium batteries due to their low fabrication cost, high sodium ionic conductivity and good structural tolerance. The high structural flexibility of NaRAPs allows variety of chemical substitutions to improve conductivity; in particular, the substitution of the anion cluster has effectively proved promoting Na+ migration, both experimentally and theoretically. Herein, we report an unexpected boost in Na+ ionic conductivity that climbs to 0.37 mS cm−1 at 485 K by introducing NO2− groups in the antiperovskite Na3ONO2 system. Its mechanism was fully investigated by neutron powder diffraction and DFT calculations, proving that the NO2− group on the lattice center, can utilize its terminal O2− anion to facilitate the Na+ migration via the Na–O interaction, when thermally excited at 485 K. The detailed migration path is also discussed by both maximum entropy method (MEM) and DFT calculations.
研究领域:
材料科学
·
固态离子学
·
无机化学
·
能源材料
·
计算材料学
✓ 已验证
DOI
高影响因子
JOURNAL OF NUCLEAR MATERIALS
·
2017
·
IF 2.048
Zhangyi Huang,Zhangkai Cao,Ke Shi,Jianqi Qi,Mao Zhou,Zhe Tang,Wei Han,Xinyue Diao,Jun Tang,Tiecheng Lu
For Gd 2 Zr 2 O 7 , nanograin ceramics with high relative densities (95%–97.4%) and small average grain sizes (61 nm - 82 nm) were successfully fabricated for the first time using field assisted sintering technique (FAST), also known as spark plasma sintering (SPS) method, in which nanopowders with an average crystallite size of 5.9 nm were synthesized via a non-aqueous gel-combustion method. Temperature was varied over a broad range to investigate its influence on the densification mechanism, microstructure evolution and hardness. The results revealed that both relative density and grain size increase with the increase of sintering temperature . The densification processes were divided to three stages. 1250 °C–1300 °C is the most suitable temperature range to fabricate dense Gd 2 Zr 2 O 7 nanograin ceramics with comparatively high hardness by FAST.
研究领域:
材料科学
·
无机非金属材料
·
陶瓷工程
·
纳米材料
·
固态化学
·
烧结工艺
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）