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991.
Huijun Wang Jie Gao Dr. Xiang Xu Dr. Baogen Liu Lingyun Yu Yadong Ren Dr. Rui Shi Prof. Zheng Zeng Prof. Liqing Li 《化学:亚洲杂志》2021,16(9):1118-1129
To investigate the effects of oxygen-containing functional groups on the adsorption of volatile organic compounds (VOCs) with different polarity, oxygen-rich porous carbon materials (OPCs) were synthesized by heat treatment of glucose/potassium oxalate material. The carbon material had a large specific surface area (1697 m2 g−1) and a high oxygen content (18.95 at.%). OPC exhibited high adsorption capacity of toluene (309 mg g−1) and methanol (447 mg g−1). The specific surface area and total pore volume determined the adsorption capacity of toluene and methanol at the high-pressure range, while the oxygen-containing groups became the main factor affecting the methanol adsorption at the low-pressure range due to the hydrogen bond interaction through the density functional theory (DFT) calculations. This study provides an important hint for developing a novel O-doped adsorbent for the VOCs adsorption applications and analyzing the role of oxygen-containing groups in the VOCs adsorption under the low-pressure range. 相似文献
992.
Fangxiao Wang Jianhai Ren Zihao Zheng Qiye Liu Dr. Chun-yang Zhang 《ChemistryOpen》2021,10(7):713-719
Fuel cells have attracted increasing attention due to their low cost, high energy density, low environmental pollution, and abundant raw materials. Oxygen reduction reaction (ORR) is a core technology of fuel cells, and the development of new electrocatalysts with high ORR performance is highly desirable. Herein, we synthesize a series of B, N co-doped hierarchical porous carbons using a soft template method with the integration of self-assembly, calcination and etching. The obtained materials exhibit hierarchical porous structures, controllable pore distribution, partial graphite structures, and B, N co-doping. They can function as the cost-effective and metal-free electrocatalysts, facilitating the diffusion of electrolyte ions and the improvement of ORR performance. Especially, the B, N co-doped porous carbon with the B-to-N molar ratio of 5 (BNC-5) displays a high ORR activity with a half-wave potential (E1/2) of 0.73 V, an onset potential (Eonset) of 0.94 V, and a high limiting current density (JL) of 5.98 mA cm−2, superior to the N-doped C (NC) and BNC-1 (the B-to-N molar ratio=1), BNC-3 (the B-to-N molar ratio=3) and BNC-7 (the B-to-N molar ratio=7) under the identical conditions. Moreover, the BNC-5 exhibits good cycling stability after 5000 cyclic voltammetry (CV) cycles and excellent tolerance toward even 3 M methanol. This research provides a new approach for the facile synthesis of dual element-doped carbon electrocatalysts with high ORR performance. 相似文献
993.
Yan-Zheng Zhang Juan-Juan Si Shan-Shan Li Guo-Zhi Zhang Shuai Wang Huo-Qing Zheng Fu-Liang Hu 《Molecules (Basel, Switzerland)》2021,26(9)
Honey has good antimicrobial properties and can be used for medical treatment. The antimicrobial properties of unifloral honey varieties are different. In this study, we evaluated the antimicrobial and antioxidant activities of nine kinds of Chinese monofloral honeys. In addition, headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) technology was used to detect their volatile components. The relevant results are as follows: 1. The agar diffusion test showed that the diameter of inhibition zone against Staphylococcus aureus of Fennel honey (21.50 ± 0.41 mm), Agastache honey (20.74 ± 0.37 mm), and Pomegranate honey (18.16 ± 0.11 mm) was larger than that of Manuka 12+ honey (14.27 ± 0.10 mm) and Manuka 20+ honey (16.52 ± 0.12 mm). The antimicrobial activity of Chinese honey depends on hydrogen peroxide. 2. The total antioxidant capacity of Fennel honey, Agastache honey, and Pomegranate honey was higher than that of other Chinese honeys. There was a significant positive correlation between the total antioxidant capacity and the total phenol content of Chinese honey (r = 0.958). The correlation coefficient between the chroma value of Chinese honey and the total antioxidant and the diameter of inhibition zone was 0.940 and 0.746, respectively. The analyzed dark honeys had better antimicrobial and antioxidant activities. 3. There were significant differences in volatile components among Fennel honey, Agastache honey, Pomegranate honey, and Manuka honey. Hexanal-D and Heptanol were the characteristic components of Fennel honey and Pomegranate honey, respectively. Ethyl 2-methylbutyrate and 3-methylpentanoic acids were the unique compounds of Agastache honey. The flavor fingerprints of the honey samples from different plants can be successfully built using HS-GC-IMS and principal component analysis (PCA) based on their volatile compounds. Fennel honey, Agastache honey, and Pomegranate honey are Chinese honey varieties with excellent antimicrobial properties, and have the potential to be developed into medical grade honey. 相似文献
994.
Xifeng Hou Yanhui Zheng Xiaolong Ma Yuheng Liu Zichuan Ma 《Molecules (Basel, Switzerland)》2021,26(4)
To expand the applications of graphene-based materials to biogas purification, a series of reduced graphene oxide aerogels (rGOAs) were prepared from industrial grade graphene oxide using a simple hydrothermal method. The influences of the hydrothermal preparation temperature on the textural properties, hydrophobicity and physisorption behavior of the rGOAs were investigated using a range of physical and spectroscopic techniques. The results showed that the rGOAs had a macro-porous three-dimensional network structure. Raising the hydrothermal treatment temperature reduced the number of oxygen-containing groups, whereas the specific surface area (SBET), micropore volume (Vmicro) and water contact angle values of the rGOAs all increased. The dynamic adsorption properties of the rGOAs towards hexamethyldisiloxane (L2) increased with increasing hydrothermal treatment temperature and the breakthrough adsorption capacity showed a significant linear association with SBET, Vmicro and contact angle. There was a significant negative association between the breakthrough time and inlet concentration of L2, and the relationship could be reliably predicted with a simple empirical formula. L2 adsorption also increased with decreasing bed temperature. Saturated rGOAs were readily regenerated by a brief heat-treatment at 100 °C. This study has demonstrated the potential of novel rGOA for applications using adsorbents to remove siloxanes from biogas. 相似文献
995.
Nhung Quynh Do Shengdao Zheng Bom Park Quynh T. N. Nguyen Bo-Ram Choi Minzhe Fang Minseon Kim Jeehaeng Jeong Junhui Choi Su-Jin Yang Tae-Hoo Yi 《Molecules (Basel, Switzerland)》2021,26(11)
Myrciaria dubia (HBK) McVaugh (camu-camu) belongs to the family Myrtaceae. Although camu-camu has received a great deal of attention for its potential pharmacological activities, there is little information on the anti-oxidative stress and anti-inflammatory effects of camu-camu fruit in skin diseases. In the present study, we investigated the preventative effect of 70% ethanol camu-camu fruit extract against high glucose-induced human keratinocytes. High glucose-induced overproduction of reactive oxygen species (ROS) was inhibited by camu-camu fruit treatment. In response to ROS reduction, camu-camu fruit modulated the mitogen-activated protein kinases (MAPK)/activator protein-1 (AP-1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and nuclear factor of activated T cells (NFAT) signaling pathways related to inflammation by downregulating the expression of proinflammatory cytokines and chemokines. Furthermore, camu-camu fruit treatment activated the expression of nuclear factor E2-related factor 2 (Nrf2) and subsequently increased the NAD(P)H:quinone oxidoreductase1 (NQO1) expression to protect keratinocytes against high-glucose-induced oxidative stress. These results indicate that camu-camu fruit is a promising material for preventing oxidative stress and skin inflammation induced by high glucose level. 相似文献
996.
997.
Shufang Ren Runyan Feng Shounian Cheng Qingtao Wang Zhixiang Zheng 《Electroanalysis》2021,33(6):1471-1483
Ti3C2TX MXene was synthesized by exfoliating pristine Ti3AlC2 phase with hydrofluoric acid. The simple methods of mechanical mixing and drop-casting of Ti3C2TX and MWCNTs were carried out to prepare sensing electrode of Ti3C2TX/MWCNTs/GCE. The composite and topography, especially the surface functional groups of Ti3C2TX/MWCNTs were analyzed by XRD, SEM, FTIR, XPS, and Raman spectrum. The results turned out that Ti3C2TX was characteristic by accordion-like 2D nanostructure with the surfaces terminated with −OH, −F, and =O. When combining with acid pretreated, the interaction between the functional groups of Ti3C2TX and MWCNTs facilitated the convenience and reproducibility of the robust modified electrodes and could make Ti3C2TX/MWCNTs/GCE possess good synergistic catalytic acceleration by increasing the electron transfer efficiency as well as adsorption and aggregation of MOP analyte onto the electrode surface. Versatile electrochemical measurements of CV, DPV and EIS were used to investigate the electrochemical performance of Ti3C2TX/MWCNTs/GCE sensing platform. The linear detection range is 0.01–100 μM with the limit of detection of 0.0092 μM (S/N=3). The sensor has good stability, repeatability, reproducibility and anti-interference. In the detection of serum and urine samples, it has a good recovery rate. 相似文献
998.
Hao Xu Jie Zhu Xiong Wang Chao Shen Shengshen Meng Kai Zheng Chao Lei Longfeng Zhu 《Molecules (Basel, Switzerland)》2021,26(5)
Developing sustainable routes for the synthesis of zeolites is still a vital and challenging task in zeolite scientific community. One of the typical examples is sustainable synthesis of aluminosilicate EU-1 zeolite, which is not very efficient and environmental-unfriendly under hydrothermal condition due to the use of a large amount of water as solvent. Herein, we report a sustainable synthesis route for aluminosilicate EU-1 zeolite without the use of solvent for the first time. The physicochemical properties of the obtained EU-1 zeolite are characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), N2 sorption, inductively coupled plasma (ICP) analysis, and solid nuclear magnetic resonance (NMR), which show the product has high crystallinity, uniform morphology, large BET surface area, and four-coordinated aluminum species. Moreover, the impact of synthesis conditions is investigated in detail. The sustainable synthesis of aluminosilicate EU-1 zeolite under solvent-free 相似文献
999.
Xiao-Qian Xu Dr. Li-Hui Cao Yan Yang Xiang-Tian Bai Fang Zhao Dr. Zhen-Hong He Dr. Zheng Yin Prof. Dr. Yang-Min Ma 《化学:亚洲杂志》2021,16(2):142-146
Over the past two decades, progress in chemistry has generated various types of porous materials for removing iodine (129I or 131I) that can be formed during nuclear energy generation or nuclear waste storage. However, most studies for iodine capture are based on the weak host-guest interactions of the porous materials. Here, we present two cationic nonporous macrocyclic organic compounds, namely, MOC-1 and MOC-2 , in which 6I- and 8I− were as counter anions, for highly efficient iodine capture. MOC-1 and MOC-2 were formed by reacting 1,1′-diamino-4,4′-bipyridylium di-iodide with 1,2-diformylbenzene or 1,3-diformylbenzene, respectively. The presence of a large number of I− anions results in high I2 affinity with uptake capacities up to 2.15 g ⋅ g−1 for MOC-1 and 2.25 g ⋅ g−1 for MOC-2 . 相似文献
1000.
We model and study the asymmetric long-range surface-plasmon waveguides using the finite-element method. We introduce two types of asymmetric structures and discuss their modal properties compared to traditional long-range surface-plasmon waveguides. Although the propagation distance is decreased, the energy-confinement capability is improved for asymmetric long-range waveguiding structures when the geometrical parameters are properly selected. Our simulation result offers guidance for tuning properties of plasmonic waveguides and providing ways for enhancing electromagnetic energy confinement in long-range surface-plasmon waveguides. 相似文献