Materials Today Communications
·
2023
·
IF 3.8
Jianhui Su,Yan Liu,Xiujing Peng,Guoxin Sun,Xuchuan Jiang
Due to the high activation energy barrier and the sporadic nature of nucleation, the temperature required for the transition from cubic dense γ-Al 2 O 3 to tripartite α-Al 2 O 3 is as high as 1100–1200 °C. In this work, a two-step strategy was employed to reduce the phase transformation temperature, and prepare α-Al 2 O 3 particles with good dispersion. As the first step, 10 nm sheet γ-Al 2 O 3 was obtained by ammonium aluminum carbonate (AACH) decomposition, which was more favorable to the crystal transformation in the next ball-milling processing. In the second step, γ-Al 2 O 3 powder with partial α-Al 2 O 3 produced in situ by ball-milling γ-Al 2 O 3 was calcined, and α-Al 2 O 3 nanoparticles were obtained at just 850 °C. The content of the α-Al 2 O 3 is determined by the Rietveld Refine method. The relationship between ball-milling time and α-Al 2 O 3 content was clarified, and the effect of α-Al 2 O 3 content on the transformation temperature and morphology of γ-Al 2 O 3 was discussed. The results showed that the α-Al 2 O 3 content rises with the increase of ball milling time, and spherical α-Al 2 O 3 nanoparticles can be obtained when the α-Al 2 O 3 content is 5 %. The addition of α-Al 2 O 3 seeds reduces the phase transition temperature but agglomeration exists. Our proposed two-step low-temperature calcination strategy is an important method for the preparation of alumina nanoparticles
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
CHEMISTRY LETTERS
·
2022
·Vol. 51
·期 4
·395-398
·
IF 1.715
Zhu Yue,Li Yue,Zhao Shipeng,Jing Ran,Zhang Heqian,Sun Daolai,Sato Satoshi
Hydrogenation of γ-valerolactone (GVL) to form 1,4-pentanediol (1,4-PDO) was performed over Co/ZrO2 catalysts with a Co metal loading of 15 wt. %. The calcination of Co/ZrO2 at high temperatures significantly promoted the catalytic activity irrespective of the decrease in the specific surface area. The 750 °C-calcined Co/ZrO2 with Co2+ species exhibited a high catalytic performance: a GVL conversion of 86.1% with a 1,4-PDO selectivity of 97.2% was achieved at 165 °C under 5 MPa H2 pressure.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Jinfeng Li,Nan Zhang,Qianwen Wang,Bo Tian,Zhigang Li,Jianwei Zhang,Haijiao Xie,Haifeng Gu,Hongtao Zhao
Pyrazolate-based materials are an important category of MOFs with robust coordinative bonds and high porosity, which possess potential advantages for uranium adsorption. However, the preparation still faces the challenges of low energy-consuming and scalable synthesis. Herein, for the first time, we demonstrated the rapid synthesis of pyrazolate-based MOFs (NiBDP-γ) by γ-irradiation induced preparation strategy and applied them to uranium adsorption. The NiBDP-γ samples can be achieved at decagram scale within minutes at room temperature and even in open-air condition. It is revealed that the high-energy γ-rays can also induce structure defects during the irradiation process, resulting in the generation of additional –NH- and –OH sites. At the optimally irradiation dose, the defective NiBDP-γ accompanied with –NH- and –OH sites show a faster removal rate and enhanced adsorption capability for U(VI). The maximum adsorption capacity for the uranium of NiBDP-γ can reach 430.8 mg/g at pH = 5 and 298 K. Kinetic adsorption results demonstrate that the introduction of defects leads to a transformation from physical adsorption to being primarily dominated by chemical adsorption. DFT calculations reveals a thermodynamically favorable binding of –NH- and –OH ligands with uranyl ions. This work offers a general approach for scalable synthesis of the pyrazolate-based MOFs and presents a novel attempt for the future application of pyrazolate-based MOFs in the treatment of uranium-containing wastewater.
研究领域:
材料科学
·
环境科学
·
核化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Shaoliang Zhu,Bingtao Zhao,Yaxin Su
High-efficiency and cost-effective adsorbents are crucial to dry capture of carbon dioxide (CO 2 ). The polyethyleneimine (PEI) was co-impregnated with tetraethylenepentamine (TEPA) on γ-alumina (Al 2 O 3 ) to synthesize the adsorbent and enhance the capture process. The influence of amine loading and operating parameters on CO 2 adsorption was investigated, and the process parameters were modeled. The results depict that the optimal loading is 50 % when functionalized either PEI or TEPA individually, which is 3.7 and 4.6 times higher than γ–Al 2 O 3 . The CO 2 capacity of γ–Al 2 O 3 functionalized with multiple amines (30 %PEI+20 %TEPA) is 2.65 mmol/g, due to the synergies of the two amines to increase the chance of CO 2 binding to the sites. Regeneration performance illustrates that the adsorbent remains at 90.2 % of the initial capacity after seven tests. The maximal capacity of 2.70 mmol/g occurs at 70 °C. Modeling results indicate the kinetics can be evaluated by the Avrami model (R 2 > 0.990) with the activation energy of 5.65 kJ/mol. The process is controlled by physical–chemical adsorption, influenced by intraparticle diffusion, as described by the deactivation model. Finally, a comparison and assessment were conducted for their techno-economic performances, and the pathway to applications was also proposed in engineering practice.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2020
·
IF 3.612
Jingru Wang,Yingyong Wang,Xili Tong,Yunwei Wang,Guoqiang Jin,Xiangyun Guo
A 3 wt% Ir/SiC catalyst prepared by the wet impregnation method showed excellent catalytic activity and stability for the aqueous hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in a batch reactor system. LA was completely converted to GVL at 50 °C and 0.2 MPa of H 2 pressure with 100% selectivity and a high turnover frequency (TOF) of 333 h −1 . The high activity of Ir/SiC catalyst could be related to the Schottky-type contact between Ir and SiC solid phases, which promotes electron transfer between support and metal. Due to the excellent acid resistance of SiC support, the Ir/SiC catalyst showed high catalytic stability and nearly no loss of activity after 5 consecutive catalytic operation cycles.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2019
·
IF 5.714
Feifei Wang,Xiaolin Yu,Maofa Ge,Sujun Wu,Juan Guan,Junwang Tang,Xiao Wu,Robert O. Ritchie
A novel self-assembly method was developed to prepare a γ-Fe 2 O 3 /graphene oxide (GO) heterogeneous catalyst that showed excellent synergy between photocatalysis and Fenton-like reactions. The γ-Fe 2 O 3 /GO catalyst prepared on the iron plates demonstrated efficient and reproducible catalytic activities for water treatment . It takes only 80 min to degrade 50 mg L −1 methylene (MB) completely, which is the main non-biodegradable dye in wastewater from the textile industry . The heterogeneous catalyst is stable over a wide range of pH (from 2.0 to 10.2) for MB degradation, and can be easily extracted from solution and repeatedly used with little loss of catalytic activity. The high activity and stability of the catalyst system can be attributed to charge separation between γ-Fe 2 O 3 and GO, which could accelerate Fenton-like process and photocatalysis. In addition, the dominant reactive oxidant species responsible for the MB degradation, including the hydroxyl radicals (•OH) and holes (h + ), were trapped on the surface of the γ-Fe 2 O 3 /GO composite, as proved by a free-radical quenching experiment. The γ-Fe 2 O 3 /GO heterogeneous catalyst could potentially provide a solution for removal of non-biodegradable dyes from wastewater in the textile industry.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Hang Qin,Wenming Guo,Hanning Xiao
Sol-gel process was modified by reverse micelles (RMs) for the preparation of γ-Al 2 O 3 ultrafiltration (UF) membranes and their applications in the efficient rejection of methyl blue and bovine serum albumin were explored. The optimized boehmite sol with a narrower particle size distribution and better sphericity was synthesized by using cetyltrimethyl ammonium bromide RMs as microreactors and was dip-coated on α-Al 2 O 3 microfiltration substrates to prepare γ-Al 2 O 3 UF membranes. It was found that not only the sol particle size, it's distribution and morphology had also an important effect on the pore size, pore size distribution , porosity and pore volume of the membrane. Additionally, the as-prepared membranes with a MWCO of 8 kDa exhibited a narrow pore size distribution (4.8–6.8 nm), relatively high pure-water flux (30.4 L/(h m 2 bar)) and excellent rejection for bovine serum albumin and methyl blue with the maximum rejection rate of 96.2% and 96.8% respectively.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2016
·
IF 5.886
Nan Li,Li Qi,Juan Qiao,Yi Chen
A ratiometric, versatile, and selective fluorescent pattern to sense and distinguish proteins on the basis of dissociation of aqueous polymer-pyrene/γ-cyclodextrin (γ-CD) inclusion complexes was developed. First, two kinds of aqueous polymer-pyrene were prepared via atom transfer radical polymerization using pyrene functionalized initiator. Then, the pyrene molecules could be accumulated into γ-CD cavity and form polymer-pyrene/γ-CD complexes, resulting in appearance of excimer emissions. The resultant complexes responded to proteins in two ways: nonmetalloproteins binding to polymer component triggered dissociation of the inclusion complexes, accompanied by alteration of pyrene excimer/monomer emission and ratiometric fluorescent intensity changes; the presence of metalloproteins could quench pyrene excimer/monomer emission because of energy transfer. Moreover, the fluorescent responses of the inclusion complexes to different proteins could be modulated by changing polymer type and chain length, resulting in a tunable selectivity and sensitivity. The proposed fluorescent inclusion complexes could provide a promising platform for sensing proteins.
研究领域:
分析化学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Carbon Resources Conversion
·
2022
·
IF 0
Abiola Ganiyat Olatoye,Jie Zhang,Qianyu Wang,Erping Cao,Wenli Li,Emmanuel Oluwaseyi Fagbohun,Yanbin Cui
In the present work, nanoporous carbon (NPC) was prepared from a metal–organic framework (zeolite imidazolate framework 8, ZIF-8). Different concentrations of graphene oxide (GO) were used to make NPC/reduced graphene oxide (NPC/rGO-x, x = 0.5, 1.0, 1.5, and 2.0) composites, and then γ-MnS/NPC/rGO-1 composite was synthesized via a simple hydrothermal technique. The electrochemical characteristics of porous carbon composites (NPC/rGO-x) and γ-MnS/NPC/rGO-1 electrodes were investigated by galvanostatic charge and discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. NPC/rGO-1 showed the highest specific capacitance of 207 F/g at 0.5 A/g. Also, the γ-MnS/NPC/rGO-1 electrode demonstrates exceptional electrochemical performance with a high specific capacitance of 300 F/g at 0.5 A/g and impressive cyclic stability of 70% capacitance retention after 10,000 cycles at 1 A/g. As a result, this study demonstrates that γ-MnS/NPC/rGO-1 electrode can be considered a promising candidate for high-performance supercapacitors.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Mei-Huan Zhao,Xiao Zhou,Yifeng Han,Dequan Jiang,Yonggang Wang,Kuo Li,Haiyan Zheng,Huiyang Gou,Ling Chen,Man-Rong Li
Intercepting metastable phases by chemical approaches is an important solution to explore structural varieties of functional materials under positive/negative pressure, as paradigmatically exemplified by the polymorph modification in Li2TiTeO6. Here, we stabilized a novel metastable Li2TiTeO6 (denoted as γ-phase) in the ordered-ilmenite-type R3 via facile topotactic reaction from Na2TiTeO6, which was found to crystallize in R3 instead of the reported R3̅ structure. The calculated equilibrium volume of γ-Li2TiTeO6 is larger than that of the ground-state Pnn2-Li2TiTeO6 (denoted as α-phase), indicating that γ-Li2TiTeO6 can only be stabilized under “negative pressure” quantified to be around −6 GPa. The γ-phase irreversibly transforms into the α-phase around 560 °C under ambient pressure, accompanied by a steep increase (∼500 times) of the second harmonic generation (SHG), indicating a potential application of γ-Li2TiTeO6 as an optical thermometer. These findings elegantly show that chemical pressure as well as physical pressure is powerful to tune the polymorphs for metastable phases and exotic properties as paradigmatically exemplified by Li2TiTeO6, which undergoes consecutive polymorph tuning of γ (−6 GPa), α (0 GPa), β (6 GPa, R3-Ni3TeO6 type), and δ (40 GPa, predicted P21/n double perovskite) phases with densified atomic packing.
研究领域:
材料科学
·
光学
·
固体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Huilin Zhang,Xiaoyu Liang,Chao Yang,Chunge Niu,Jide Wang,Xintai Su
Nano γ-Fe 2 O 3 modified bentonite magnetic composites (γ-Fe 2 O 3 /Bent) were synthesized via an annealing approach of the ferric oleate and bentonite compounds. The γ-Fe 2 O 3 nanoparticles with narrow size distribution and an average diameter of 32 nm were equably dispersed on the surface and between layers of the bentonite nanosheets , which mainly owed to the complete mixture of ferric oleate and hydrophobic modified bentonite. The γ-Fe 2 O 3 /Bent composites exhibited typical ferromagnetic characteristics with the saturation magnetization of 22.31 emu/g and coercivity of 209 Oe. Adsorption performance measurement indicated that the γ-Fe 2 O 3 /Bent composites are a kind of excellent adsorbent with fast adsorption rate, high adsorption capacity, 99.99% removal rate and easily magnetic separation process for the removal of cationic dye methylene blue (MB). Adsorption kinetics and isotherms were studied to describe the adsorption process , and the electrostatic adsorption mechanism was confirmed by zeta potential measurement.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Applied Sciences-Basel
·
2022
·Vol. 12
·期 19
·10101
·
IF 2.838
Han Gao,Weimin Kong,Shuyuan Zhou,Xuwei Wang,Qingrong He,Yanchun Dong
Chemical warfare agents (CWAs) are highly toxic and fast-acting and are easy to cause large-scale poisoning to humans and livestock after being released. The activated carbon used for CWAs adsorption has disadvantages of limited adsorption capacity, easy aging and deactivation. Metal oxides have environmental stability, and they are characterized by long lasting and broad spectrum when used for thermal catalytic decomposition. Therefore, in this study, the supported copper–cerium catalyst CuO-CeO2/γ-Al2O3was prepared using an equal volume impregnation method. The thermal catalytic decomposition performance was studied using sarin CWAs simulant dimethyl methyl phosphonate (DMMP) as the target compound. The results show that the CuO-CeO2/γ-Al2O3catalyst with a CeO2loading of 5% exhibited better thermal catalytic decomposition performance of DMMP. The catalyst provided protection against DMMP for 237 min at 350 °C; CuO was highly dispersed on CuO-5% CeO2/γ-Al2O3, and there was a strong interaction between Cu and Ce on CuO-5% CeO2/γ-Al2O3, which promoted the generation of surface-adsorbed oxygen, leading to a better thermal catalytic decomposition performance of DMMP. This study is expected to provide a reference for the study of catalysts for the thermal catalytic decomposition of CWAs.Keywords:nerve agent;dimethyl methyl phosphonate;thermocatalytic;CuO;CeO2;γ-Al2O3
研究领域:
环境科学
·
化学工程
✓ 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）