FeCoNiIrPtPd/NCNT exhibits 3.4- and 1.6-fold higher levels of mass activity than does commercial Pt/C in the hydrogen evolution reaction (HER) and ethanol oxidation reaction (EOR), respectively.

The development of high-performance cathode materials is critical to the practical application of sodium-ion batteries (SIBs). O3-type NaCrO2 (NCO) is one of the most competitive cathodes, but it suffers from rapid capacity decay caused by severe irreversible structural evolution. An Mg-Ti co-doped Na0.99Cr0.95Mg0.02Ti0.03O2 (NCO-MT) cathode material is designed and synthesized via a facile solid-state reaction to enhance the cyclability of NCO. A capacity retention of 71.6% after 2500 cycles with the capacity fade rate of 0.011% per cycle is achieved for NCO-MT at 5 C, which is attributed to the highly reversible crystal structure during cycling. Our findings offer a novel insight into the high-performance O3-type layered cathode materials for SIBs and are beneficial to promote the development of high-rate SIBs.

Protein surface charge engineering has promising applications for a deeper understanding of the adsorption and action mechanisms between enzymes and substrates. The engineering modification of beta-glucosidase (BGL) is conducive to greatly reducing the negative feedback inhibition in biomass resource utilization and improving the utilization efficiency. Herein, the mutants BGL-14 and BGL-1, which had the largest difference in surface zeta-potential (-12.5 mV and -4.6 mV) obtained by rational design in previous studies, were selected to explore their adsorption behaviors on cellulose and lignin using an adsorption isotherm model. The results showed that more negative charges on the enzyme surface facilitated adsorptive contact with substrates while repelling lignin to reduce competitive adsorption, and that the monolayer coverage might be the main mechanism for cellulose/lignin adsorption of enzyme. Secondly, commercial cellulases were added to the modified BGLs to form a "cocktail" of enzymes (BGL-C) to synergistically participate in the in situ saccharification of biomass pretreated with ionic liquids (ILs). The BGL-14-C synergistic hydrolysis system presented a strong conversion ability in low concentrations of ILs, and its catalytic biomass production of reducing sugars at 5% (v/v) 1-ethyl-3-ethyl-imidazolium diethylphosphate ([EEIM]DEP) reached a yield of 1.24 g L-1, which was 130% and 136% of that of WT-C and BGL-1-C, respectively. BGL-1-C, on the other hand, exhibited higher thermal stability, with the catalytic rate remaining at 51% when the temperature was increased from 50 degrees C to 70 degrees C in 1-ethyl-3-methyl-imidazolium diethylphosphate ([EMIM]DEP). Our study delves into the role of enzyme surface charge in reducing unproductive adsorption and increasing the probability of contact with the substrate, providing a theoretical basis for understanding the role of surface charge in mixed systems.

Nonylphenol (NP) is a common pollutant with high biotoxicity in industrial waste waters, such as printing and dyeing, cleaning, preparation of surfactant and detergents, etc., and can disrupt the endocrine and reproductive system. Therefore, its emission is imperative to be monitored. To achieve the specific detection of NP, we herein synthesized a novel fluorescent ionic liquid (NAIm) bearing a double naphthalene ring. The fluorescent intensity of NAIm was significantly quenched upon the addition of NP, and the underlying quenching mechanism belonged to a static quenching mode. DFT theoretical calculations suggested that the band gap increased by 0.11 eV, where the ground state electrons were transferred from the HOMO orbitals of NP to the LUMO ones of NAIm. The specific detection of NP by NAIm was demonstrated to be feasible. NAIm was also able to identify and quantify NP in ambient samples, and the fortified recoveries for NP was in the range 89-110 %. The newly developed fluorescent ionic liquid holds great promise in specific detection of NP in environmental waters.

A NaCrO2 @C flexible free-standing cathode is designed and fabricated via a facile electrospinning strategy, in which electrochemically active NaCrO2 nanoparticles homogeneously dispersed in the flexible carbon nanofibers. Serving as the binder-free cathode for sodium-ion batteries, the as-constructed NaCrO2@C flexible free-standing cathode delivers a long cycling life (81 % capacity retention after 1000 cycles) with a high loading (7.6 mg cm(-2)). The enhancements for sodium-ion insertion/desertion is assigned to the dramatically decrease the polarization between electrodes and avoid the volume expansion during high-rate cycling. The NaCrO2@C flexible free-standing cathode opens up exciting possibilities for the development of advanced flexible sodium-ion batteries with both excellent mechanical flexibility and electrochemical properties.

Herein, a dual-emitting fluoroprobe was pioneered for the sensitive and selective detection of hydroquinone (HQ) in environmental waters, which was based on integration of a tailor-made fluorescent ionic liquid ([TBAOH][NA]) with Eu3+ (([TBAOH][NA]/Eu3+). HQ could substantially enhance the 365-nm fluorescence intensity (FI365) of [TBAOH][NA]/Eu3+, whereas no prominent variation ocurred in FI615. After HQ binding with [TBAOH][NA], the electronic structure of S1 was completely pi-pi*, and the orbital overlap of the latter was much higher, thereby promoting photon transitions. After some key factors were optimized using a centralcomposite-design (CCD) approach, this fluroprobe provided a linear response from 0.5 to 100 mu M and detection limit of 0.15 mu M for HQ assay, which was comparable to analytical performance by conventional HPLC-DAD analysis. Overall, the prominent advantages of as-developed fluoroprobe lie in two aspects: (1) Employing the ratio of two well-resolved emission and significantly differential responses to HQ greatly enhance sensitivity and accuracy through a self-calibration system; and (2) [TBAOH][NA] has not only the superiority of "green solvent" like conventional ionic liquids, but also possesses strong luminescence signal owing to introducing 1-naphathoic acid as an anion into tetrapropylammonium hydroxide. Consequently, this dual-emitting fluoroprobe is endowed with great potential in on-site and outdoor HQ monitoring.

Herein, a naphthene carboxylic acid-based dicationic ionic liquid ([C3(MIM)2][NA]2) was synthesized and characterized in detail. The [C3(MIM)2][NA]2 was used as a high-efficiency fluorescent probe for 4-nitrophenol (4-NP) quantification based on a "ON-OFF" strategy in environmental waters and soils. At the 330-nm excitation wavelength, this fluoroprobe exhibited a strong emission at 415 nm with an absolute quantum yield of 8.5 %. The fluorescence of [C3(MIM)2][NA]2 could be effectively quenched by 4-NP through the fluorescence resonance energy transfer (FRET) process. By DFT theoretical calculation, the band gap of the [C3(MIM)2][NA]2 + 4-NP system was reduced as low as 3.10 eV, suggesting the occurrence of ground state electron transfer from HOMO of 4-NP to LUMO of [C3(MIM)2][NA]2. A satisfactorily linear equation was obtained when plotting the fluorescence intensities of [C3(MIM)2][NA]2 vs the concentrations of 4-NP with a detection limit of 0.3 mu M. The newly developed method was successfully used to detect 4-NP in environmental water and soil samples with satis-factory fortification recoveries of 97.2-104.2 %. Moreover, it is comparable with or even better than the China National Standard Method (HG-T-4296-2012), i.e., conventional titration method, in the aspects of detection limit and linear range. To sum up, the the as-constructed fluorescence sensor holds great potential application in routine monitoring of 4-NP in environmental waters and soils.

Herein, we fabricated blue-fluorescence carbon quantum dots modified by ionic liquids (ILs-CQDs) with a quantum yield of 18.13

实践教学是高校人才培养的重要环节,有助于提高学生的工程实践能力与创新创业能力.分析了目前地方高校应用化学专业综合实验存在的问题,在优化实验项目、革新教学模式、改善考核评价体系、课程思政等方面做了一些教学实践与探索,以期为同类院校开展实验教学改革提供参考与借鉴.

Conventional ionic liquids possess several disadvantages, such as high viscosity, difficult sampling/retrieval, and great loss in aqueous solution, limiting their wide applications in the pretreatment field. To solve these drawbacks, we synthesized a quaternary ammonium polymeric ionic liquid (PIL) and pressed it into an effervescent tablet for developing an effervescence-enhanced dispersive solid-phase extraction method (QAP-EDSE). The pressed effervescent tablet was composed of PIL as an extractant, tartaric acid as an acidic source, NaHCO3 as an alkaline source, and water-soluble starch as a filler, respectively. Under the CO2-driven dispersion, the QAP-EDSE method integrated rapid enrichment, extraction, and dispersion into one synchronous step. Employing the one-factor-at-a-time approach, several important variables were optimized as follows: 200 mg of P[VBTHEA]Cl as sorbent, 400 mu L of acetone as elution solvent, 5 min of elution, solution pH 9.0, and 1 : 1.25 molar ratio of alkaline to acidic sources. Combining LC-DAD analysis, this proposed approach offered the limits of detection as low as 0.11-0.31 mu g L-1 and satisfactory recoveries of 81.40-102.62% for five sulfonamides (SAs) in environmental waters. The lower relative standard deviations (1.9-6.7%) evidenced the higher intraday and interday experimental precision by this method. Overall, the newly developed method is environmentally benign, time-saving, and easy to operate with low detection limit and high recovery and thus shows excellent prospects in the trace-level detection of SAs in environmental waters.

A chitosan-based flame retardant with a caged structure, chitosan maleic acid mono (1-thio-phosa-4-hydroxymethyl-2,6,7-trioxa-bicyclic [2.2.2] octan-4-methylene) ester salt (CS-MA-SPEPA), was synthesized and characterized. Cone calorimeter (CC) results indicated that the introduction of CS-MA-SPEPA into an unsaturated polyester resin (UPR) matrix could effectively reduce the HRR, TRR, and SPR. More importantly, the incorporation of CS-MA-SPEPA suppressed the release of toxic gases (CO) from the UPR matrix. The char residues results implied that the combination of CS-MA-SPEPA into UPR increased the degree of graphitization of the matrix and made char residues intumescent and tight, which could efficiently block the exchange of oxygen and heat.

刺激响应性材料作为新型智能材料,在日常生活和工业生产方面有着重要应用,但能耗高、难以精准控制及循环可逆性差限制了其使用范围.偶氮苯基团是一种合成相对简单、循环可逆性好、易于精准控制、相对节能的光敏性官能团.离子液体是一类蒸汽压低、热稳定性好、可设计、对环境污染程度较低的新型液体材料.因此含有偶氮苯基团的离子液体是一类既具有光响应性,又具有离子液体特性的新型功能材料,凭借其在紫外/可见光(UV/Vis)照射下发生光致异构化,从而引起物化性质和材料性能发生可控变化,成为目前研究的热门.本工作综述了近年来含有偶氮苯基团的离子液体在光控智能材料中的应用,对含有偶氮苯结构单元的离子液体在光控电导率、光控自组装、光控相行为、光控CO2的捕获与释放和光响应可控离子凝胶黏弹性等领域的研究进展进行了详细介绍,并对其未来的发展方向进行了展望.含有偶氮苯结构单元的离子液体具有独特的优势,在可持续发展的大背景下能够为智能材料、绿色化学的发展提供新的思路.

Currently, the issue of natural flammability of unsaturated polyester resin (UPR) severely restrains its application. In this study, polymeric flame retardant poly methyl vinyl di (1-thio-2,6,7-trioxal-1-phosphabicyclo [2.2] octane-4-methoxy) silane (PMVDOS) with P–S–Si-based cage unit was synthesized. The UPR/PMVDOS composites were prepared by adding different ratios of PMVDOS into UPR. The flame-retardant properties and the char layer structure of UPR samples were evaluated via the limiting oxygen index (LOI), vertical burning test, cone calorimeter test, scanning electron microscopy, laser Raman spectroscopy, and X-ray photoelectron spectroscopy. The results showed that UPR/PMVDOS composites reached the UL-94 V-0 rating with the LOI value of 27.8%, and the carbon residue increased from 4.9% for pure UPR to 14.9% when the content of PMVDOS was 18 wt%. The peaks of heat release rate, total heat release, and total smoke production were comparatively reduced. The flame-retardant mechanism of PMVDOS mainly acted on the condensed phase. The surface of the matrix was covered with the polymer containing phosphorous and silicon dioxide particles, preventing the escape of flammable volatiles and isolating the exchange of oxygen and heat, thus, the degradation of the matrix could be inhibited. This research provides a solution to improve the flame retardancy of UPR.

Currently, the issue of improving the flame‐retardant performance of unsaturated polyester resin (UPR) has drawn a lot of attention. In this study, methyl vinyl di (1‐thio‐2,6,7‐trioxal‐1‐phosphabicyclo [2.2] octane‐4‐methoxy) silane (MVDOS) with P‐N‐Si‐based cage unit was synthesized, and it was utilized as a reactive flame‐retardant monomer to modify UPR. The UPR/MVDOS composites were prepared by introducing different ratios of MVDOS into UPR via the reaction of crosslink. The efficiency of the resulted composites was investigated by using the limiting oxygen index (LOI), vertical burning test, and cone calorimeter test. The results showed that the composites reached the V‐0 rate without dripping, and the LOI value was 29.1% when the content of MVDOS was as low as 18 wt%. Cone calorimeter tests revealed the peak of heat release and CO production of UPR/MVDOS‐18 were 238.2 KW/m 2 and 0.0167 g/s, which were respectively lower than the ones of neat UPR. The introduction of MVDOS also increased the stability of UPR composites. Furthermore, the scattering electron microscopy, laser Raman spectroscopy, and X‐ray photoelectron spectroscopy studies revealed that the incorporation of MVDOS stimulated the UPR matrix to generate char layer with increased graphitization degree, which provided a good barrier to prevent heat and oxygen from being transferred and then protected the materials inside from further burning. This research provides a new way to obtain flame‐retardant UPR composites with high performance.

铂族金属作为一类不可再生资源,在工业和军工方面有着重要应用,但其在分配和供求上存在严重不均衡,凸显了其资源化回收再利用的重要性.离子液体作为一种性质优良的绿色溶剂,成为科学研究的热点.本文对近年来利用离子液体萃取铂族金属铂、钯和铑等的研究进行了综述,并对其未来的发展方向进行了展望.

以三(羟甲基)氨基甲烷盐酸盐、三氯氧磷和甲基乙烯基二氯硅烷为主要原料,两步合成了一种有机硅双环笼状膦酸酯阻燃剂,即甲基乙烯基二(1–氧代–1–膦杂–2,6,7–三氧杂双环[2.2.2]辛烷基–4–亚氨基)硅烷(MVDIS),并通过傅里叶变换红外光谱、核磁共振氢谱表征产物的化学结构.确定最佳的反应条件为:在氮气保护下,溶剂为二乙二醇二甲醚,反应温度为90℃,笼状膦酸酯胺与甲基乙烯基二氯硅烷物质的量比2.1:1的条件下反应10 h,产物MVDIS的产率可达91.4％.通过热重–差热、极限氧指数、垂直燃烧和扫描电镜对阻燃性能与机理及烧蚀产物的微观形貌进行分析.结果表明,MVDIS具有良好的热稳定性与气相阻燃机理,且作为阻燃单体引入不饱和聚酯树脂后获得了良好的阻燃与自熄性能.

国内多数高等院校的化学相关专业都开设专业外语与文献检索的相关课程,在该课程中增添思政元素对学生的专业学习以及品德养成具有积极的促进作用.本文讨论了课程思政的必要性,对专业知识与思政元素的结合进行了设计,重点介绍了思政教育的措施,从爱国情怀、辩证思维、创新意识等多方面进行了课程思政的探索与实践.

Vesicles or micelles prepared from amphiphiles with azobenzene (Az) moieties and long alkyl chains have attracted much attention in drug delivery systems. To induce release behavior from smart carriers via trans-cis photoisomerization of the Az groups, UV light exposure is typically used, but it can damage DNA and hardly penetrates cells. In this paper, Az-containing phospholipids without long alkyl tails were designed and synthesized; in these compounds, the end group of the Az moiety was substituted with a -NO2 and -OCH3 group (abbreviated N6 and M6, respectively). N6 self-assembled into H-aggregates with an interdigitated bilayered structure in water through the antiparallel orientation due to π-π interactions of the Az group, the attractive van der Waals forces, and the interactions and bending behavior of the phosphocholine groups. Vesicles showing visible light stimuli-responsive behavior were obtained by mixing N6 and M6, and the release of encapsulated calcein was triggered by visible light.

Ionic liquids (ILs) bearing tetrahydropyran-2H-yl (THP)-protected thiol moieties were designed and synthesized as extractants for Pd(II)-selective extraction into an IL phase from a mixed aqueous HCl solution of Pd(II) and Pt(IV) salts. 1H NMR measurements revealed that metal-selective THP-deprotection by the Pd(II) salt played a critical role to introduce the Pd(II)-selective extraction ability.