2022-06-14 2022, Volume 2 Issue 2

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  • Research Article
    Hong-Yan Li, Chao Li, Ying-Ying Wang, Ming-Hui Sun, Wenda Dong, Yu Li, Bao-Lian Su

    Lithium-selenium battery is nowadays a highly competing technology to the commercial Li-ion battery because it has a high volumetric capacity of 3253 mAh cm-3 and gravimetric capacity of 675 mAh g-1. However, the practical application of lithium-selenium (Li-Se) batteries is impeded by the shuttle effect of the soluble polyselenides during the cycling process. Herein, we report the in situ growth and pyrolysis of the metal-organic framework zeolitic imidazolate framework-8 (ZIF-8) on three-dimensional (3D) interconnected highly conductive multiwalled carbon nanotubes (MWCNTs). The obtained composites are used to anchor Se for advanced Li-Se batteries. Compared with the isolated ZIF-8 derived microporous carbon, our synthesized ZIF-8 derived porous carbon@MWCNTs (ZIF-8-C@MWCNTs) 3D highly conductive networks facilitate lithium ion diffusion and electron transportation. The particle size of ZIF-8 crystals has an important impact on the battery performance. By adjusting the particle size of ZIF-8, the electrochemical reaction kinetics in ZIF-8-C@MWCNTs 3D networks can be tuned. The optimized particle size of ZIF-8 around 300-500 nm coated on MWCNTs composite achieves an excellent initial discharge capacity of 756 mAh g-1 and a stabilized capacity of 468 mAh g-1 at 0.2 C after 200 cycles. Combining the 3D MWCNTs with the appropriate size of ZIF-8 derived microporous carbon particles could highly improve the performance of the Li-Se battery. This work provides significant guidance for further structural design and host particle size selection for high-performance Li-Se batteries.

  • Review
    Yaru Li, Dongsheng Zhang, Wei Qiao, Hongwei Xiang, Flemming Besenbacher, Yongwang Li, Ren Su

    The photocatalytic process employing nanostructured semiconductor materials has attracted great attention in energy production, CO2 reduction, and water/air purification for decades. Recently, applying heterogeneous photocatalyst for the synthesis of valuable chemicals is gradually emerging and considered as a promising process for the conversion of cheap resources (i.e., biomass derivatives, polyols, and aromatic hydrocarbons). Compared with traditional thermal catalytic approaches, the photocatalytic process provides a mild reaction condition and flexible platform (photocatalyst) that allows precise tweaking of reaction intermediates and reaction pathways, thus resulting in fine control of the selective synthesis of specialized chemicals that are challenging for thermal catalysis. In this review, we summarize recent achievements in photocatalytic synthesis of various industrial important chemicals via photo-oxidative and photo-reductive processes. The selective oxidation of alcohols and aromatics, epoxidation of alkenes, hydrogenation of gaseous molecules and hydrocarbons, and coupling reactions by means of various photocatalysts including metal oxides, supported plasmonic metal nanostructures, conjugated organic polymers, anchored homogeneous catalysts, and dye-sensitized heterostructures are discussed from a material perspective. In addition, fundamental understandings of reaction mechanisms and rational design of nanostructured photocatalysts for enhancing efficiency, selectivity, and stability are discussed in detail.

  • Editor's Choice
    Xiangdong Yao
  • Research Highlight
    Wei Tan, Feng Shi
  • Short Communication
    Yunting Zeng, Junjuan Shi, Kehuan Li, Jiaqi Li, Hao Yu, Fang Fang, Xin-Qi Hao, Houyu Zhang, Ming Wang

    In recent years, fluorescent supramolecular materials have received significant attention due to their wide application prospects. However, the relationship between the conformation of supramolecules and their photophysical properties remains an open question. In this study, two rhomboidal metallacycle isomers, SA and SB, self-assembled with trans- and cis-isomers of tetraphenylethylene-based ditopic pyridyl ligands (LA and LB), and a 120° di-platinum (II) acceptor were prepared. Compared with metallacycle SB constructed by cis- tetraphenylethylene (TPE)-based ligand LB, the curved rhomboidal metallacycle SA constructed with trans-TPE-based ligand LA can restrict molecular motions of the aromatic groups on TPE and exhibits better light-emitting properties. Moreover, curved SA also exhibited better fluorescence stability than isomer SB towards molecules with strongly electron-withdrawing groups. This work provides a new platform to explore the relationship between conformation and the corresponding photophysical properties.

  • Review
    Rebecca El Khawaja, Savita Kaliya Perumal Veerapandian, Rim Bitar, Nathalie De Geyter, Rino Morent, Nicolas Heymans, Guy De Weireld, Tarek Barakat, Yang Ding, Grêce Abdallah, Shilpa Sonar, Axel Löfberg, Jean-Marc Giraudon, Christophe Poupin, Renaud Cousin, Fabrice Cazier, Dorothée Dewaele, Paul Genevray, Yann Landkocz, Clémence Méausoone, Nour Jaber, Dominique Courcot, Sylvain Billet, Jean-François Lamonier, Bao-Lian Su, Stéphane Siffert

    Volatile Organic Compounds (VOCs) are known to be hazardous and harmful to human health and the environment. In mixtures or during repeated exposures, significant toxicity of these compounds in trace amounts has been revealed. In vitro air-liquid interface approaches underlined the interest in evaluating the impact of repeated VOC exposure and the importance of carrying out a toxicological validation of the techniques in addition to the standard chemical analyses. The difficulties in sampling and measuring VOCs in stationary source emissions are due to both the complexity of the mixture present and the wide range of concentrations. The coupling of VOC treatment techniques results in efficient systems with lower operating energy consumption. Three main couplings are outlined in this review, highlighting their advantages and relevance. First, adsorption-catalysis coupling is particularly valuable by using adsorption and catalytic oxidation regeneration initiated, for example, by selective dielectric heating. Then, several key aspects of the plasma catalysis process, such as the choice of catalysts suitable for the non-thermal plasma (NTP) environment, the simultaneous removal of different VOCs, and the in situ regeneration of the catalyst by NTP exposure, are discussed. The adsorption-photocatalysis coupling technology is also one of the effective and promising methods for VOC removal. The VOC molecules strongly adsorbed on the surface of the photocatalyst can be directly oxidized by the photogenerated hole on the photocatalyst (e.g., TiO2).