Green Chemical Engineering
·
2021
·
IF 0
Qingping Xin,Xueting Cao,Dandan Huang,Shuo Li,Xinghui Zhang,Guangyu Xuan,Mengting Wei,Lei Zhang,Xiaoli Ding,Yuzhong Zhang
One type of new light-responsive hierarchical metal organic framework (MOF) has been successfully prepared using Co(NO 3 ) 3 ·6H 2 O as the metal salt and 4,4′-azobenzenedicarboxylic acid as the ligand by microwave method for the first time. It is found that MOF [Co(AzDC)] exhibits a light-responsive characteristic to SO 2 adsorption due to the presence of azo group from the ligand. The light-responsive hierarchical MOFs are incorporated into Matrimid® 5218 (PI) matrix to prepare mixed matrix membranes (MMMs) for gas separation application. The morphology, crystallinity, chain mobility and thermal stability of MMMs are explored. Results show that Co(AzDC) may elevate both the CO 2 (SO 2 ) permeability and CO 2 (SO 2 )/N 2 selectivity of the MMMs. In particular, the Co(AzDC) doped MMMs exhibit the significantly improved CO 2 (SO 2 )/N 2 selectivity from 33 (123) for PI control membrane to 78 (420) for MMMs, overcoming the 2008 Robeson upper bound for CO 2 /N 2 system. Size-sieving effect of Co(AzDC) with pore size 0.35 nm enhances the selectivity, while the –N=N– group from Co(AzDC) shows affinity to CO 2 molecular rather than N 2 , also elevating selectivity of MMMs. In brief, enhanced selectivity of high-performance membrane is attributed to incorporation of Co(AzDC) particles, which displays synergistic effects both in size-sieving and CO 2 -philic interaction for CO 2 /N 2 separation. Smart highly selective interface is constructed in MMMs by switching the configuration of MOFs from cis to trans . The SO 2 permeability and SO 2 /N 2 selectivity of MMMs are investigated under both visible light and ultraviolet light states, and the SO 2 /N 2 separation performance under visible light is notably improved in comparison with that under ultraviolet light state.
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DOI
RSC Advances
·
2022
·Vol. 12
·期 52
·33716-33724
·
IF 4.036
Jie Hu,Lei Li,Hao Li,Ying Zhai,Fushun Tang,Zhe Zhang,Banglin Chen
The mixed bimetal metal–organic framework Ni0.37Co0.63-MOF-74 has been constructed by the solvothermal method for NO adsorption. The results showed that bimetal Ni0.37Co0.63-MOF-74 takes up NO with a capacity of up to 174.3 cc g−1 under ambient conditions, which is 16.3% higher than that of the best single metal Co-MOF-74. The IAST adsorption selectivity for a NO/CO2 binary mixture can reach a maximum of 710 at low adsorption partial pressure, while the regeneration performance can be retained even after five cyclic adsorption–desorption experiments. Its separation performance was further confirmed by breakthrough experiments, indicating this new bimetal Ni0.37Co0.63-MOF-74 as one of the best materials for NO adsorption and separation in flue gas.
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DOI
高影响因子
POLYMER
·
2021
·
IF 4.43
Yuxuan Feng,Jizhong Ren,Hui Li,Dan Zhao,Lujie Sheng,Yongdong Wu,Wenyuan Zhao,Maicun Deng
Block polymers with thermal annealing are attractive routes to produce 6FDA-based polyimide membranes with enhanced gas separation performance. However, some 6FDA-based polyimide membranes exhibit different gas separation behavior trends under the thermal annealing process. In this work, two 6FDA-DETDA/DMMDA block polyimide membranes with different 6FDA-DETDA block lengths were prepared and annealed at three temperatures (150 °C, 250 °C and 350 °C). To investigate the thermal annealing process and its influence on the thermal cross-linking behavior and aggregation structures, in situ XRD and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) were employed. Based on the orbital-weighted Fukui function calculated by Time-dependent density functional theory (TD-DFT) and AP-XPS spectra, it's found that free radicals cross-linking that induced by 350 °C annealing occurred in imide rings, and resulted in the destroyed imide rings and decreased average interchain distances in both block polyimides. However, the massive 6FDA-DETDA block hindered imide rings from destruction and resulted in a slight molecular filtration, which benefited the gas transport of small kinetic diameter gases. As a result, 350 °C annealed membrane of bPI-2 exhibited enhanced gas separation performance. We expect that this work will shed light on the effect of thermal annealing on the gas separation behavior of block polyimides and offer a way to tune gas separation performance by thermal annealing.
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DOI
高影响因子
Research
·
2023
·
IF 11
Feng Niu,Fugong Zhou,Zhixun Wang,Lei Wei,Jie Hu,Lei Dong,Yifei Ma,Mei Wang,Suotang Jia,Xuyuan Chen,Zhaomin Tong
Traditional metal oxide semiconductor (MOS) gas sensors have limited applications in wearable devices owing to their inflexibility and high-power consumption by substantial heat loss. To overcome these limitations, we prepared doped Si/SiO2 flexible fibers by a thermal drawing method as substrates to fabricate MOS gas sensors. A methane (CH4) gas sensor was demonstrated by subsequently in situ synthesizing Co-doped ZnO nanorods on the fiber surface. The doped Si core acted as the heating source through Joule heating, which conducted heat to the sensing material with reduced heat loss; the SiO2 cladding was an insulating substrate. The gas sensor was integrated into a miner cloth as a wearable device, and the concentration change of CH4 was monitored in real time through different colored light-emitting diodes. Our study demonstrated the feasibility of using doped Si/SiO2 fibers as the substrates to fabricate wearable MOS gas sensors, where the sensors have substantial advantages over tradition sensors in flexibility, heat utilization, etc.
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DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Songjian Zhao,Dongyao chen,Haomiao Xu,Jian mei,Zan Qu,Ping Liu,Yong Cui,Naiqiang Yan
The zirconium metal-organic framework material UiO-66 was doped with Ag nanoparticles and investigated for the removal of elemental mercury (Hg 0 ) in flue gas . Physical and chemical characterization of the adsorbents showed that adding Ag did not change the crystal structure and morphology of the UiO-66. Ag doping can improve the redox activity of UiO-66, and the adsorbent exhibited high thermal stability and surface area. Hg 0 removal experiments indicated that UiO-66 exhibited the higher performance compared with P25 and activated carbon, and the addition of Ag exhibited a significant synergistic effect with the UiO-66, which had highest Hg 0 adsorption capacity (3.7 mg/g) at 50 °C. Furthermore, the Hg 0 removal mechanism was investigated, revealing that Hg 0 is removed by the formation of an Ag amalgam and channel adsorption at low temperature, and through Ag-activated oxygen oxidation and channel capture at high temperature.
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2014
·
IF 4.384
Xiaohui Meng,Dong Qiu
Centimeter-sized two-dimensional (2D) colloidal single crystals of polystyrene (PS) particles were fabricated at the water/air interface by capillary-modulated self-assembly. Different from previous reports, in this work, emulsifier was used to facilitate the stress release during 2D colloidal crystal formation by adjusting the interparticle lateral interactions. With the assistance of compressed nitrogen flow, 2D hexagonal colloidal single crystals of centimeter size were obtained under appropriate emulsifier concentrations. A new method was also developed to transfer the 2D colloidal crystals from the air/water interface to the desired substrate without obvious disturbance. This new transferring method was proven not to be sensitive to surface wettability nor curvature, thus 2D colloidal single crystals with large areas could be obtained on different kinds of substrate.
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Xingxing Fu,Piaoyun Yang,Xufeng Xiao,Di Zhou,Rui Huang,Xianghui Zhang,Fan Cao,Juan Xiong,Yongming Hu,Yafang Tu,Yanan Zou,Zhao Wang,Haoshuang Gu
Formaldehyde is one of the most serious threats to human health owing to the wide-spread of indoor decoration of modern buildings in recent years. The online monitoring of formaldehyde concentration of the indoor environment has become an urgent issue in modern society. In this work, an ultrafast and highly selective room-temperature formaldehyde gas sensor based on the semiconductor nanomaterials was developed. The Pt-decorated MoO 3 nanobelts were employed as the formaldehyde sensing materials, which were synthesized through hydrothermal and chemical reduction process. The results show that the Pt nanoparticles loading on the surface of the nanobelts are metallic and well crystalized. After the surface-decoration by Pt nanoparticles , the room-temperature HCHO sensing performance of the MoO 3 nanobelts could be greatly enhanced. With only 0.61% (atomic ratio) of Pt nanoparticles loading on MoO 3 , the sensor response towards 200 ppm of HCHO could be increased from 5.7% to 39.3%. The average response and recovery rate were also improved, leading to ultrafast response and recovery process at room temperature. At the LOD (limit of detection) of 1 ppm, the response and recover time of the sensor was only 8.8 s and 0.94 s, respectively. Furthermore, the Pt-decorated MoO 3 nanobelts also exhibited outstanding selectivity against other typical interference VOC including methylbenzene, methanol, ethanol and acetone, as well as good anti-interference performance towards water vapors . The great improvement of the sensor performance could be attributed to the spill-over and catalytic effect of Pt nanoparticles toward HCHO at room temperature.
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DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2020
·
IF 7.635
Tong Zhang,Qiancun Cheng,Bo Jiang,Yudong Huang
Gas sensors for the detection of toxic gases have attracted extensive attention due to the growing environment issue. Polysiloxane is an ideal substrate material for the flexible electronic devices. In this work, dual-activity siloxane monomer with double bonds and epoxy groups (MAGETDS) was synthesized via hydrosilylation reaction. A series of flexible polysiloxane substrate were then prepared based on the dual-activity siloxane via UV-thermal induced polymerization reaction. Besides, the regulating of reactive monomers endows the flexible polysiloxane with tunable properties. Then, polyaniline (PANI) was synthesized via a facile in-situ chemical oxidation polymerization technique and directly loaded on the polysiloxane substrate to fabricate a polyaniline/polysiloxane flexible nanocomposite film as a novel room temperature NH 3 sensor. This novel NH 3 sensors exhibited good selectivity, reproducibility and a low detection limit of 5 ppm towards NH 3 at room temperature. The strategy we developed may provide a promising approach in flexible electronics for room temperature gas sensing application.
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Hongbing Wang,Yifei Yang,Linsen Zhou,Jun Chen,Linan Lin,Xinchun Mao,Wei Cui,Yunxi Yao
The reactive interfacial sites upon supported catalysts provide an alternative pathway to enable the reactants activation in an energetically favorable mode, thus decreasing the energy barrier and promoting the catalytic efficiency. By virtue of structural characterization, in-situ spectroscopic analysis, kinetic assessments and density functional theory (DFT) calculations, supported Pt/TiN catalysts are systematically studied to interrogate H 2 O activation on the Pt-TiN interfacial sites and its catalytic function during the low-temperature water gas shift (WGS). It is found that the partially oxygen-covered TiN surface is highly efficient for H 2 O activation by oxygen-assisted dissociation with an energy barrier of 0.41 eV, much less than that on metallic Pt surface. The formed hydroxyls binding on Ti sites, observed by in-situ X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD), could readily react with the adjacent CO adsorbed on Pt clusters with the reaction energy barrier of 0.43 eV to attain the individual catalytic cycle. Benefiting from the enhanced H 2 O activation, the catalytic turnover rate of CO-H 2 O reaction on Pt/TiN is 3.8 and 20.3 times higher than that on traditional Pt/TiO 2 and Pt/SiO 2 at 403 K, respectively. The interfacial reactive sites are the origin of low-temperature WGS on Pt/TiN catalysts.
✓ 已验证
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2022
·
IF 7.926
Zhuang Liu,Dachao Ma,Liwu Liang,Xuan Hu,Mengxue Ling,Zhou Zhou,Lizhong Fu,Zheng Liu,Qingge Feng
Hydrothermal treatment (HTT) of polyvinyl chloride (PVC) can efficiently remove chlorine (Cl) to produce low Cl hydrochar for solid fuel. This work performed co-hydrothermal treatment of PVC recycled plastics (PVC R ) with biomass, then tried to reveal the combustion behavior and Cl migration behavior during combustion of PVC-derived hydrochar . It is shown that the hydrothermal temperature was the dominant factor affecting the degradation and dechlorination of PVC R . Treated at 220 ℃ for 60 min, the dechlorination efficiency of PVC R was 4.88 wt% and it was significantly increased to 34.09 wt%, 28.60 wt% and 32.50 wt% when PVC R was co-treated with bagasse, bagasse + high impact polystyrene (HIPS) and bagasse + acrylonitrile butadiene styrene (ABS), respectively. The substitution of Cl by hydroxyl (-OH) and elimination were two main dechlorination pathways. Bagasse could provide abundant -OH so as to promote the dechlorination of PVC R . Interestingly, in the combustion of PVC R and hydrochars, the Cl was mainly released in the form of HCl at lower temperature combustion stage but C-Cl mostly emitted at higher temperature combustion stage . The emitted Cl species strongly depends on the Cl content in hydrochar and combustion temperature , but did not show relevance to the existence form of Cl in hydrochar. Hydrothermal dechlorination could sharply reduce HCl emission.
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Xiao Xu,Qiang Yang,Chao-yang Wang,Xiao-ling Ge,Hua-lin Wang
Although compact separation by a hydrocyclone is popular in the chemical and petro-chemical industry, the separation of dissolved gas from continuous liquid in a hydrocyclone is rarely mentioned, and few investigations consider the gas solubility changes occurring with the cyclone flow. This work investigates dissolved carbon dioxide separation from water by an inner cone hydrocyclone. When the inlet mass flow is less than 1.2 m 3 /h, increasing the inlet mass flow could increase the separation efficiency. When the inlet mass flow is more than 1.2 m 3 /h, increasing the inlet mass flow will decrease the separation efficiency. An optimum inlet mass flow of 1.2 m 3 /h can provide the maximum separation efficiency of 40.2%. Turbulence simulations also assist in analyzing the flow pattern and the separation progress.
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2012
·
IF 1.693
Jiangfeng Yang,Qiang Zhao,Hong Xu,Libo Li,Jinxiang Dong,Jinping Li
We prepared several different surfaces and pore volumes on small pore zeolites by hydrothermal synthesis and ion exchange (Li+, Na+, and Ca2+) based on three basic gas diameter grade structures of zeolites: KFI (0.39 × 0.39 nm), CHA (0.38 × 0.38 nm), and LEV (0.36 × 0.48 nm), which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and elemental analysis. The surface area and microporous volumes were calculated using the Dubinin–Radushkevitch (D-R) equation based on CO2 adsorption at 273 K. The CHA was synthesized with a lower Si/Al ratio, and the surfaces and microporous volumes were changed greatly by ion exchange. KFI had a higher Si/Al ratio, and the scope of the surface could be kept smaller. Focusing on the CO2, CH4, and N2 adsorption isotherms at high pressure (1 MPa), we found that the samples were exchanged by Li+ and Na+ with bigger surfaces and greater adsorption volumes. The orifice diameter was very important in the sieving of CO2 and N2 or CO2 and CH4, while Na-LEV had an excellent sieving effect because N2 and CH4 could not diffuse into its structure like CO2. From the viewpoint of the separate adsorption equilibria: Na-zeolites had the highest data adsorption equilibrium selectivity for CO2 and N2 or CO2 and CH4, followed by Li-zeolites, which only had a strong adsorption potential of CO2; K-zeolites with high SCO2/N2 and SCH4/N2, based on the strong adsorption of CO2 and CH4. We conclude that the adsorption potential order was K-zeolites > Na-zeolites > Li-zeolites, so the bigger ions had a stronger affinity.
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DOI
高影响因子
危险品化学品经营许可证（带存储）