JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2022
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IF 6.76
Weihao Zhu,Yuanfeng Wu,Guiyun Yi,Xiaoxiao Su,Qiangsheng Pan,Shengbin Shi,Olayinka Oderinde,Guomin Xiao,Chuanxiang Zhang,Yulong Zhang
The present work is aimed at studying the synergistic catalysis of the bimetal ZIFs containing Co and Zn metal ions prepared by solvothermal method in the degradation of organic pollutants under ambient conditions. The bimetal mixed ZIFs were further characterized by some techniques such as XRD, SEM, TG-DTG, XPS, UV–vis, ESR, and N 2 -adsorption. Interestingly, the sample prepared with equal metal ions (1Zn:1Co) showed the highest catalytic performance for methylene blue (MB) degradation (94.10 %). This may be associated with the interaction between cobalt and zinc within the adjacent lattice, which make the MB molecule to be easily adsorbed and degraded on empty electron orbit. Furthermore, the highest degradation of MB was achieved with 98.83 % under the optimized conditions (catalyst weight of 50 mg, pH of 5, 3 h, 30 °C). Besides, the various substrates such as methyl orange, indole, rofloxacin, methyl blue, and tetracycline were also investigated under the same conditions. Additionally, the DFT calculation results suggested the more orbital distribution (LUMO, HOMO) of ZIF(1Zn:1Co) can result to more electrons being easily captured, and generate more radicals via electron transfer. Finally, the photocatalytic degradation of MB is consistent with the first law of kinetics, and the activation energy is 26.797 KJ/mol in the presence of ZIF(1Zn:1Co).
研究领域:
环境科学
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材料科学
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计算化学
✓ 已验证
DOI
高影响因子
Nano Research
·
2023
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IF 9.9
Fang Diyi,Liu Chuanlei,Chen Yu,Peng Qilong,Wu Kongguo,Chen Yuxiang,Jiang Hao,Wu Yuan,Shen Benxian,Wu Qiumin,Wu Di,Sun Hui
Porous heterogeneous lyophobic systems (HLSs) find potential applications in energy restoring, dissipating, and absorbing. However, the development of controllable HLSs still lacks rational structure design of nanoporous materials matching the molecular sizes of adopted liquids. Besides that, thoroughly understanding the underlying transportation mechanism in the confined nano channels is greatly challenging. In this work, a series of Co/Zn bimetallic zeolitic imidazolate frameworks (ZIFs) with tunable structures were synthesized via regulating the Co to Zn ratios and employed to investigate the intrusion–extrusion of liquid water in confined nanopores. Structural characterizations confirm the heterometallic coordination in the Co/Zn-doped frameworks. Water intrusion–extrusion experiments unlock the relationship between the intrusion pressure and the nanopore size and realize the evolution of the HLSs between molecular spring and shock-absorber. In addition, cycling tests indicate the reversible structure change of Co/Zn ZIFs encountering pressure-induced water intrusion. In combination with molecular dynamics simulations, we present that the water multimers intrude into nanopores of ZIFs in chain-like forms along with dissociation of hydrogen bonds (HBs). Water molecules in the pre-intrusion state exhibit reduced HBs in response to the increase of pressure and linear structure with 1.6–3.0 HBs on average. After transition to the post-intrusion situation, the associative configuration of water tends to exhibit the tetrahedral structure. Herein, we highlight the roles of pore size and HB in synergically dominating the pressure-induced intrusion–extrusion of liquid water in hydrophobic nanopores. Furthermore, the present work can also guide the development of functional guest–host systems based on porous architectures.
研究领域:
材料科学
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化学工程
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
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2023
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IF 5.3
Junhui Liu,Bing Li,Mengting Li,Yuan Hu,Shan Han,Xinwen Guo
Transformation of abundant and economical feedstock CO2 and renewable H2 into valuable hydrocarbons is considered a prospective route for the storage of renewable energy. However, it is also a challenge to prepare highly stable and active catalysts. Herein, active and stable catalysts were designed by pyrolysis of the Fe-modified bimetal-ZIFs with varied ratios of Zn/Co, in order to introduce Zn in situ as a structure promoter and Co for an increase of the CO2 conversion. CO2 conversion increased by improving the Co content, while CH4 selectivity also increased obviously. The superior selectivity of value-added hydrocarbons and the ratio of olefins and paraffins (O/P) were obtained without addition of alkali metals. The O/P is 1.76 over FeZnCo-NC-59. The N-doped porous carbon catalysts delivered a good stability in a 1000 h test under harsh reaction conditions. The stable catalysts provide a promising prospect for further application in CO2 hydrogenation.
研究领域:
化学工程
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催化科学
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能源转换
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Xiaodong Yang,Feifei Peng,Longfei Zhang,Xiang Wang,Shulin Liu,Wei Yang,Luhong Zhang,Na Yang
Amorphous LDHs materials have been considered promising electrocatalysts for OER since their abundant coordination sites but still undergo poor stability. It is an efficient strategy to rationally architect amorphous/crystalline hybrid nanostructures on the ZIFs-derived amorphous LDH counterparts. Herein, we provide a facile two-step method to fabricate crystalline Ag NPs decorated amorphous QLDHs (Ag/QLDHs) nanosheet arrays on the Ni foam through ions exchange and spontaneous redox reaction. Based on the multi-metal synergetic effects (Co, Zn, Fe, Ni) and regulation of Ag nanoparticles (NPs), the as-formed Ag/QLDHs with heterogeneously hierarchal structures exhibit excellent OER performance with a low overpotential of 216 and 247 mV under 10 and 100 mA cm −2 in 1 M KOH, respectively, together with highly structural robustness. Through using the in situ-Raman spectroscopy, we reveal that the Ag NPs play the important role in enhancing the oxidation state of Ni and Fe species in Ag/QLDHs, which facilitates the generation of active MO x (OH) y at a much lower potential. The synthesized approach proposed in this work will supply a promising pathway for constructing amorphous/crystalline hybrid structures applied to alkaline water oxidation.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Chunjie Li,Xin Qian,Mengyuan Hao,Xuefei Wang,Shiqi Zhu,Mei Guo,Haoting Gong,Yonggang Zhang
PAN-based carbon fibers have been widely used in aerospace materials due to high specific strength , high specific modulus and many other outstanding features. As one kind of carbon-based electromagnetic wave (EMW) absorption material, carbon fibers are expected to absorb more EMW due to multiple polarization losses and large specific surface area in which EMW can be reflected many times. However, they also have certain disadvantages when used as EMW absorption material due to their high dielectric constant, low permeability and low reflection loss strength. Herein, a facile hydrothermal synthesis method was used to construct the three-dimensional (3D) bimetal-organic framework compound onto the surfaces of polyacrylonitrile(PAN)-based ultrahigh modulus carbon fibers (UHMCFs). Through the control of key parameters in the synthesis process, 3D bimetallic ZIF particles with different morphologies were assembled on the fiber surfaces, and a further high temperature heat treatment resulted in significantly improved EMW absorption properties. The results showed that three fibrous structures including rod-shaped, threadlike and flower-like morphologies had been formed with the introduction of CoZn-ZIFs. Among them, the uniform structure of rod-shaped sample could be preserved after carbonization and it also showed optimal EMW absorption performance, e.g. its minimum reflection loss (RL min ) and effective absorption bandwidth (EAB) values were − 67.67 dB (EMW loss above 99.9 %) and 4.28 GHz, respectively, with the thickness of 2.00 mm. In the final, the EMW absorption mechanism of CoZn-bimetallic ZIF decorated UHMCFs including interfacial loss, conductive loss, polarization loss, multiple scattering and excellent impedance matching was discussed in detail.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
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