SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Chengyuan Duan,Meili Ding,Yi Feng,Mengjue Cao,Jianfeng Yao
Integration of Lewis acid and base sites and oxygen surface groups in one catalyst is favorable to promote CO 2 cycloaddition reaction. Here, Zn-ZIF-L was used as starting material to design one kind of catalyst with multiple active sites via pyrolysis and oxidization treatment. The well-dispersed ZnO nanoparticles and pyridinic nitrogen in nitrogen-doped carbon serve as Lewis acid and base sites to activate epoxide and CO 2 while oxygen surface groups help promote the ring-opening reaction of epoxides. Results show that Zn-ZIF-L derived catalyst displays high catalytic activities for CO 2 cycloaddition (6 h, 83% of yield) under mild conditions (70 °C and 0.1 MPa CO 2 ) and outperforms ZIF-8 derived catalyst. Moreover, the obtained catalyst also achieves a satisfactory photothermal catalysis of cycloaddition reaction under light irradiation (120 mW/cm 2 ), which makes our sample a promising catalyst for CO 2 conversion.
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Sustainable Materials and Technologies
·
2023
·
IF 9.6
Dandan Ouyang,Liuqian Yang,Ya-nan Wang,Yongsheng Li,Feng Yu,Jiao Yin
Carbon materials have great potential in achieving excellent potassium-ion batteries (PIBs), while the low theoretical capacity of carbon materials limits the application of potassium ion batteries . Here, we reported an amorphous porous carbon with rich N-S bonds (N-S/C) by simple self-assembly possess and pyrolysis possess. The prepared N-S/C material possesses plentiful N-S bonds, which can act as active center to enhance the electrochemical capacity and accelerate transport dynamics. In addition, abundant porous structure can increase the contact area between electrode materials and electrolyte to shortens the diffusion path of ion transport, thereby improving the rate performance. As PIBs anodes, the N-S/C material exhibits a markedly enhanced reversible capacity of 389 mAh g −1 at 50 mA g −1 , excellent cycling stability (188.8 mAh g −1 at 500 mA g −1 after 1000 cycles) and rate performance (105 mAh g −1 at 2 A g −1 ). Importantly, the in-situ Raman unravels a reversible mechanism that intercalation/deintercalation of K + into/from the N-S/C, and the electrochemical analysis shows the N-S bond can improve the capacitive activity and enable fast kinetics toward superior K + -storage. These results demonstrate a promising carbonaceous anode material for PIBs and may provide guidance for designing of electrode materials of PIBs.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
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IF 9.9
Jiabing Luo,Yan Zhou,Xingzhao Wang,Yufeng Gu,Wanli Liu,Shutao Wang,Jun Zhang
We report the synthesis and electrocatalytic properties of a CoMoO 4 -CoP heterostructure anchored on a hollow polyhedral N -doped carbon skeleton (CoMoO 4 -CoP/NC) for water-splitting applications. The preparation involved the anion exchange of MoO 4 2- to the organic ligand of ZIF-67, the self-hydrolysis of MoO 4 2- , and NaH 2 PO 2 phosphating annealing. CoMoO 4 was found to enhance thermal stability and prevent active site agglomeration during annealing, while the hollow structure of CoMoO 4 -CoP/NC provided a large specific surface area and high porosity that facilitated mass transport and charge transfer. The interfacial electron transfer from Co to Mo and P sites promoted the generation of electron-deficient Co sites and electron-enriched P sites, which accelerated water dissociation. CoMoO 4 -CoP/NC exhibited excellent electrocatalytic activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1.0 M KOH solution, with overpotentials of 122 mV and 280 mV at 10 mA cm −2 , respectively. The CoMoO 4 -CoP/NC‖CoMoO 4 -CoP/NC two-electrode system only required an overall water splitting (OWS) cell voltage of 1.62 V to achieve 10 mA cm −2 in an alkaline electrolytic cell. In addition, the material showed comparable activity to 20% Pt/C‖RuO 2 in a pure water home-made membrane electrode device, demonstrating potential for practical applications in proton exchange membrane (PEM) electrolyzers. Our results suggest that CoMoO 4 -CoP/NC is a promising electrocatalyst for efficient and cost-effective water splitting.
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高影响因子
Journal of Environmental Chemical Engineering
·
2023
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IF 7.7
Donghuan Meng,Ye Lei,Menghan Pang,Jianrong Qiu,Chenghua Fan,Yuyan Feng,Dongbo Wang
In the graphitic carbon nitride-based photocatalytic reaction, the redox ability and electron transport ability of photocatalyst have an important influence on its activity. The Photo-Fenton reaction system was constructed by modifying N-doped carbon quantum dots (N-CQDs) on the surface of supramolecular self-assembled carbon nitride and introducing Fe ions into the carbon nitride planar structure . The xFe/N-CQDs/MCN1 catalysts with different iron contents were prepared, which had significant degradation effect on organic pollutants . Among them, 0.2Fe/N-CQDs/MCN1 degraded 76% of ciprofloxacin (CIP) within 120 min. Various characterizations demonstrate that photocatalytic activity are enhanced due to the surface modification of N-CQDs enhancing electron transfer rate on the surface of photocatalysts and the doping of Fe ions providing active sites for Fenton reaction . At the same time, the formation of chemical bonds limits the leaching of iron and avoids secondary environmental pollution . These results indicate that the novel catalyst has excellent application potential in the field of environmental photocatalysis .
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MACROMOLECULES
·
2023
·
IF 5.5
Jinkang Dou,Minghui Xu,Bojun Tan,Hongchang Mo,Xianming Lu,Bozhou Wang,Ning Liu
Nitrile N-oxide-based click ligation is a very promising technique for polymer crosslinking due to the unique advantages of catalyst-free and byproduct-free reactions. For this technique, nitrile N-oxides that are sufficiently stable at room temperature and have high reactivity under mild conditions are very desirable. Usually, neighboring bulky substituents are introduced to enhance the stability of nitrile N-oxides, which however bring the reactivity down due to the high steric hindrance. Herein, methyl groups, small-sized substituents, were introduced into the o,o′-positions of phenyl nitrile N-oxides to enable high stability and high reactivity. Thus, several novel aromatic nitrile N-oxides were synthesized. Among them, ditopic aromatic nitrile N-oxides were prepared through three simple steps including etherification, oximation, and oxidative dehydrogenation, whereas stable tritopic aromatic nitrile N-oxides were synthesized by directly introducing the nitrile N-oxide functionality into the corresponding trifunctional compounds to avoid undesirable side reactions. These nitrile N-oxides as ligation reagents exhibited very high reactivity, and efficient catalyst-free crosslinking of natural rubber was achieved at room temperature to give elastomers with good mechanical properties, revealing the potential of such nitrile N-oxides as useful crosslinkers for unsaturated bond-containing polymers. This work provides reliable synthesis of stable ditopic/tritopic aromatic nitrile N-oxides, broadening the application of the nitrile N-oxide-based click ligation technique toward catalyst-free and byproduct-free polymer crosslinking.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
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IF 8.6
Jianping Yuan,Pan Yang,Liying Long,Haike Yang,Yiqun Chen,Zizheng Liu,Qing Shao,Feng Wu,Pengchao Xie,Jun Ma
As a metal-free alternative, graphene-based catalysts have attracted increasing attention for minimizing the risk of heavy metal exposure. In this study, a nitrogen–doped reduced graphene oxide (N-rGO) material was synthesized by a one–pot hydrothermal method using dicyandiamide as the precursor. N-rGO has been adopted for sulfite activation for the first time, to our knowledge. The established N–rGO/sulfite system could effectively remove As(III) in water, and the solution pH and dissolved oxygen were the most important factors affecting the removal. The results of density functional theory calculations indicated that sulfite activation was more likely to occur on C atoms adjacent to the N dopant. It was inferred that the generated hydroxyl radical (HO • ) played a vital role in As(III) oxidation. In addition, the conversion of pyridinic nitrogen to pyrrolic nitrogen was responsible for the poor long–term stability of N-rGO. These results demonstrated that N-rGO was a promising catalyst for water treatment.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2023
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IF 7.2
Yunqi Yu,Jianting He,Tong Wang,Xinsheng Qiu,Kangcheng Chen,Qin Wu,Daxin Shi,Yaoyuan Zhang,Hansheng Li
Nitrogen-doped carbon nanotubes (N-CNTs) prepared by carbonization of polypyrrole nanotubes (PPy-NTs) are used as supports. Pt–CeO 2 /N-CNTs electrocatalysts are successfully prepared by in-situ growth of Pt and CeO 2 nanoparticles (NPs) via a one-step coupling method of co-deposition and ethylene glycol reduction. Through structural characterization and electrochemical tests of the prepared electrocatalysts, the effects of preparation conditions on the structure of the electrocatalysts and their electrocatalytic activity for methanol oxidation were systematically investigated. The results verify that the Pt–CeO 2 /N-CNTs electrocatalysts were prepared using N-CNTs calcined at 700 °C as a support and 15 mM alkali concentration. They have the largest electrochemical active area and methanol oxidation mass activity of 85 m 2 g −1 (Pt) and 722 A g −1 (Pt), respectively. Furthermore, the electrochemical stability and anti-CO poisoning performance of the electrocatalysts are significantly better than those of the commercial Pt/C electrocatalysts. The highly-dispersed Pt and CeO 2 in Pt–CeO 2 /N-CNTs, a large number of N sites, and the synergistic action of Pt, CeO 2 , and N-CNTs result in a catalyst with excellent electrocatalytic activity, stability, and resistance to CO poisoning. The support structure and the dispersion of Pt and CeO 2 can be controlled by changing the preparation conditions, which provides a basis for the industrial application of direct methanol fuel cells.
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JOURNAL OF HAZARDOUS MATERIALS
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2021
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IF 10.588
Huiwang Dai,Wenjun Zhou,Wei Wang,Zhiqi Liu
In this study, three Co/N-C catalysts were prepared by pyrolysis of bimetallic zeolitic imidazole frameworks with different Co/Zn ratio, and the critical active Co species in peroxymonosulfate (PMS) activation was investigated. The three catalysts had distinct cobalt species but similar N configuration and graphitization degree. The Co species were distributed as single atoms (Co SAs) at a Co/Zn molar ratio of 1:8, while Co nanoclusters (Co NCs) and Co nanoparticles (NPs) would be formed with further increase in Co content. The degradation efficiency of BPA did not show correlation with the increasing of Co content in catalyst. Based on the catalytic performance comparison and reactive species detection, Co SAs was identified as active sites, which could interact with PMS to generate 1 O 2 via path of PMS→HOO*→O*→ 1 O 2 . However, the role of NCs and NPs in directly activating PMS was negligible. In addition, the increase of Co content in Co/N-C catalyst would result in mass cobalt leaching, which enhanced the BPA degradation via homogeneous catalytic reactions with Co IV as reactive species. It is an effective way to design the Co/N-C catalyst with high catalytic activity and stability via regulating the formation of Co SAs.
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MINERALS ENGINEERING
·
2021
·
IF 4.765
Huifang Yang,Kaihua Huang,Xiaoyu Cao,Xiaoping Huang,Zhanfang Cao,Hong Zhong,Hu Zhou,Jianxian Zeng,Jianrong Xue,Rui Zhang
The flotation performance and hydrophobic mechanism of O-ethyl-N-benzoyl thionocarbamate (EBZTC) on chalcopyrite were first estimated by single flotation experiments, batch adsorption experiments, contact angle measurements, DFT calculation and FTIR analysis. Single flotation experiments illustrated that a flotation recovery of 96.7% was achieved to chalcopyrite when EBZTC was used compared to 90% with SIBX at pH 6.5. Adsorption experiments indicated that the adsorption process of EBZTC on chalcopyrite surface was an exothermic monolayer chemisorption process. Hydrophobic mechanism demonstrated that EBZTC chemisorbed onto the chalcopyrite surface through the chemical reactions of C O and C S groups to the copper species with the formation of C O Cu and C S Cu bonds, which resulted in the coverage of the hydrophobic groups of EBZTC onto the chalcopyrite surface to enhance its hydrophobicity.
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International Journal of Polymeric Materials and Polymeric Biomaterials
·
2021
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IF 2.604
Changgui Li,Yuheng Qiu,Rongguo Li,Mengting Li,Ziyu Qin,Xueqiong Yin
A thermo-sensitive film composed of polycaprolactone and poly(N-isopropylacrylamide) was fabricated via electrospinning, with ketoconazole as the model drug. The morphology, elemental composition, and surface hydrophilicity of the nanofibres were characterized, and the results showed that nanofibres switched from a hydrophilic to a hydrophobic state as the temperature increased from 25 °C to 37 °C. The drug release profiles of the films suggested that sustained drug release behavior was achieved, and a lower temperature induced a faster delivery. Therefore, the prepared nanofibres could be highly applicable as wound dressings for on-demand and sustained drug release systems based on their temperature-responsive properties.
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CHEMICAL ENGINEERING JOURNAL
·
2021
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IF 13.273
Chenglin Liu,Zhijie Liang,Chun Yang,Fuyi Cui,Zhiwei Zhao
N-nitrosamines (NAs), a class of emerging nitrogenous disinfection byproducts , have been detected remarkably in drinking/reclaimed water. There is a significant risk of excessive levels of NAs in the chlorination of the polluted source water, especially in the direct chlorination of nitrite-enriched groundwater. Considering the co-pollution of nitrite and micro-organic pollutants on groundwater, experiments were conducted on chlorination of nitrite-enriched water with precursor of antibiotics, and it was confirmed that the Cl 2 : N (molar ratio of chlorine to nitrite), contacting time, pH, and DO appreciably influenced the NAs formation potential. The molecular electric potential revealed that different dissociation status of precursors has a specific correlation with NAs formation potential (FP). The nitrite significantly increased the NAs FP because the reactive nitrogen species (RNS) formed in the oxidation process from nitrite to nitrate. Sequences of transformation products are determined to support the RNS promoted hypothesis of N-nitrosodimethylamine (NDMA) formation mechanism; furthermore, theoretical investigation in the reaction of dimethylamine (DMA) with different RNS verified the above hypothesis.
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RSC Advances
·
2021
·Vol. 11
·期 56
·35268-35273
·
IF 3.361
Bin Li,Jizhen Liu,Dandan Fu,Yongjing Li,Xiaojia Xu,Ming Cheng
In this study, a simple and eco-friendly method was proposed to efficiently prepare nanocomposite hydrogels with excellent mechanical properties and satisfactory pH response behaviour by frontal polymerization (FP) of DEM in close to 4 minutes. Acrylamide (AM) and choline chloride (ChCl) were used as raw materials to synthesize deep eutectic monomers (DEMs). Nitrogen-doped carbon nanotubes were dispersed in DEMs as fillers, and poly(acrylamide)/nitrogen-doped carbon nanotube (PAM/N-CNT) nanocomposite hydrogels were prepared by FP. The non-covalent interactions between PAM hydrogels and N-CNTs was verified by Fourier infrared spectroscopy. The mechanical properties of PAM/N-CNT nanocomposite hydrogels were investigated, as well as the swelling and pH response properties. The results showed that the compressive strength of PAM hydrogels was significantly enhanced by the addition of N-CNTs due to the hydrophobic interaction of N-CNTs, which also causes sensitive response properties of the PAM hydrogels in acid solution.
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