Photoinduced Oxygen Reduction Reaction Boosts the Output Voltage of a Zinc–Air Battery

Utilization of solar energy is of great interest for a sustainable society, and its conversion into electricity in a compact battery is challenging. Herein, a zinc–air battery with the polymer semiconductor polytrithiophene (pTTh) as the cathode is reported for direct conversion of photoenergy into electric energy. Upon irradiation, photoelectrons are generated in the conduction band (CB) of pTTh and then injected into the π_2p* orbitals of O₂ for its reduction to HO₂^?, which is disproportionated to OH^? and drives the oxidation of Zn to ZnO at the anode. The discharge voltage was significantly increased to 1.78 V without decay during discharge–charge cycles over 64 h, which corresponds to an energy density increase of 29.0 % as compared to 1.38 V for a zinc–air battery with state‐of‐the‐art Pt/C. The zinc–air battery with an intrinsically different reaction scheme for simultaneous conversion of chemical and photoenergy into electric energy opens a new pathway for utilization of solar energy.     

Investigation on two triphenylene based electron transport materials

Promoting electron mobility is the key to designing high performance electron transport materials(ETMs). Formation of intermolecular interaction can be helpful to enhance their electron mobilities as a result of more ordered molecular stacking.Here, to reveal the inherent influence of intermolecular π-π stacking on the electron mobilities, we designed two ETMs, namely,2,4-diphenyl-6-[3-(2-triphenylenyl)phenyl]-1,3,5-triazine(TPTRZ) and 2,4-diphenyl-6-[4′-(2-triphenylenyl)[1,1′-biphenyl]-3-yl]-1,3,5-triazine(TPPTRZ). Thermal, photophysical and electrochemical measurement results indicate they are good ETM candidates. Additionally, TPTRZ and TPPTRZ exhibit high electron mobilities of 3.60×10~(-5) and 3.58×10~(-5) cm~2V-1 s~(-1), respectively, at an electric field of 7×10~5 V cm~(-1). By taking X-ray single crystal structure, theoretical calculation and time of flight(TOF) results into consideration, it is revealed that strong intermolecular π-π stacking induced by planar triphenylene and triphenyltriazine units renders TPTRZ and TPPTRZ small energetic and positional disorder parameters, and results in their high electron mobilities thereby. By further enhancing intermolecular π-π stacking, ETMs with even higher electron mobilities can thus be anticipated.     

多孔离子液体的构筑及应用

多孔液体(Porous Liquids, PLs)是一类结合了多孔固体永久性孔隙与液态流动性优势的新材料. 自2007年, PLs的概念被首次提出以来, 其在合成策略与应用领域方面均取得了较大的突破. 然而, 传统的PLs因高黏度、高密度、高熔点与高原材料成本等缺陷极大程度制约了其在流动工业系统中的大规模应用. 因此, 迫切需要寻求理想的位阻溶剂用于制备先进的多孔液体. 离子液体(Ionic Liquids, ILs)因独特的可调节物理特性、非挥发性、高稳定性、易获得、经济性高、低再生能耗等特性, 使其成为构筑PLs中最具有应用前景的理想溶剂之一. 在过去的5年间, 基于多种ILs与先进多孔固体(如有机笼、金属有机框架、中空碳、沸石、多孔聚合物等)制备的多孔离子液体(Porous Ionic Liquids, PILs)被陆续报道. PILs独特的永久性孔隙、无溶剂挥发、再生能力强、黏度可调、低熔点、高稳定性等特性加快了其在气体吸附、分离、催化、萃取、分子分离等领域的快速发展. 本综述围绕PILs的构筑策略、特性、应用领域等阐述了其研究进展. 最后, 对PILs在制备中存在的挑战与未来的研究方向进行了归纳与展望.     

Photosensitive peptide hydrogels as smart materials for applications

Photosensitive supramolecular peptide hydrogels with the gelators forming by the integration of photosensitive moieties and peptides have been briefly summarized the hydrogelation capabilities, the expressing manner serving as smart materials, and practical applications.     

Visible light induced photocatalytic degradation of phenol by polymer-modified semiconductors: Study of the influencing factors and the kinetics

To investigate the influencing factors and the kinetics of photocatalytic degradation of phenol, experiments were carried out using conjugated polymer poly(fluorene-co-thiophene) (PFT) sensitized TiO₂ and ZnO under LED (light-emitting diode) lights of the wavelength of 450–475 nm. Influencing factors, such as initial phenol concentration, photocatalyst dosage and pH value on the photocatalytic degradation of phenol were studied in detail. The reaction kinetics was found to follow pseudo first-order law.     

Electrocatalytic Synthesis of Nylon-6 Precursor at Almost 100 % Yield

Synthesis of cyclohexanone oxime via the cyclohexanone-hydroxylamine process is widespread in the caprolactam industry, which is an upstream industry for nylon-6 production. However, there are two shortcomings in this process, harsh reaction conditions and the potential danger posed by explosive hydroxylamine. In this study, we presented a direct electrosynthesis of cyclohexanone oxime using nitrogen oxides and cyclohexanone, which eliminated the usage of hydroxylamine and demonstrated a green production of caprolactam. With the Fe electrocatalysts, a production rate of 55.9 g h⁻¹ g_cat⁻¹ can be achieved in a flow cell with almost 100 % yield of cyclohexanone oxime. The high efficiency was attributed to their ability of accumulating adsorbed hydroxylamine and cyclohexanone. This study provides a theoretical basis for electrocatalyst design for C−N coupling reactions and illuminates the tantalizing possibility to upgrade the caprolactam industry towards safety and sustainability.     

Palladium-Catalyzed Fluorinative Bifunctionalization of Aziridines and Azetidines with gem-Difluorocyclopropanes

An unprecedented Pd-catalyzed fluorinative bifunctionalization of aziridines and azetidines was successfully developed via regioselective C−C and C−F bond cleavage of gem-difluorocyclopropanes, leading to various β,β′-bisfluorinated amines and β,γ-bisfluorinated amines. This reaction was achieved by incorporating a 2-fluorinated allyl group and a fluorine atom scissored from gem-difluorocyclopropane in 100 % atom economy for the first time. The mechanistic investigations indicated that the reaction underwent amine attacking 2-fluorinated allyl palladium complex to generate η²-coordinated N-allyl aziridine followed by fluoride ligand transfer affording the final β- and γ-fluorinated amines.     

Layer-by-layer assembled microgel films with high loading capacity: reversible loading and release of dyes and nanoparticles

Multilayer films containing microgels of chemically cross-linked poly(allylamine hydrochloride) (PAH) and dextran (named PAH-D) were fabricated by layer-by-layer deposition of PAH-D and poly(styrene sulfonate) (PSS). The successful fabrication of PAH-D/PSS multilayer films was verified by quartz crystal microbalance measurements and cross-sectional scanning electron microscopy. The as-prepared PAH-D/PSS multilayer films can reversibly load and release negatively charged dyes such as methyl orange (MO) and fluorescein sodium and mercaptoacetic acid-stabilized CdTe nanoparticles. The loading capacity of the film for MO can be as large as approximately 3.0 microg/cm2 per bilayer, which corresponds to a MO density of 0.75 g/cm3 in the film. The high loading capacity of the PAH-D/PSS films originates from the cross-linked film structure with sufficient binding groups of protonated amine groups, as well as their high swelling capability by solvent. The loaded material can be released slowly when immersing the films in 0.9% normal saline. Meanwhile, the PAH-D/PSS multilayer films could deposit directly on either hydrophilic or hydrophobic substrates such as quartz, polytetrafluoroethylene, polystyrene, poly(ethylene terephthalate), and polypropylene. The microgel films of PAH-D/PSS are expected to be widely useful as matrixes for loading functional guest materials and even for controlled release.