Catalytic Properties of Nanoscale Iron‐Doped Zirconia Solid‐Solution Aerogels

Nanoscale iron‐doped zirconia solid‐solution aerogels are prepared via a simple ethanol thermal route using zirconyl nitrate and iron nitrate as starting materials, followed by a supercritical fluid drying process. Structural characteristics are investigated by means of powder X‐ray diffraction (XRD), thermal analyses (TG/DTA), N₂ adsorption measurements and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results show that the resulting iron‐doped solid solutions are metastable tetragonal zirconia which exhibit excellent dispersibility and high solubility of iron oxide. Further, when the Fe:(Fe+Zr) ratio x is lower than 0.10, all of the Fe³⁺ ions can be incorporated into ZrO₂ by substituting Zr⁴⁺ to form Zr_1?xFe_xO_y solid solutions. Moreover, for the first time, an additional hydroxyl group band that is not present in pure ZrO₂ is observed by DRIFTS for the Zr(Fe)O₂ solid solution. This is direct evidence of Fe³⁺ ions incorporated into ZrO₂. These Zr_1?xFe_xO_y solid solutions are excellent catalysts for the solvent‐free aerobic oxidation of n‐hexadecane using air as the oxidant under ambient conditions. The Zr_0.8Fe_0.2O_y solid‐solution catalyst demonstrates the best catalytic properties, with the conversion of n‐hexadecane reaching 36.2 % with 48 % selectivity for ketones and 24 % selectivity for alcohols and it can be recycled five times without significant loss of activity.     

Inorganic–Organic Hybrid Multifunctional Solid Electrolyte Interphase Layers for Dendrite-Free Sodium Metal Anodes

Constructing a stable and robust solid electrolyte interphase (SEI) is crucial for achieving dendrite-free sodium metal anodes and high-performance sodium batteries. However, maintaining the integrity of SEI during prolonged cycle life under high current densities poses a significant challenge. In this study, we propose an integrated multifunctional SEI layer with inorganic/organic hybrid construction (IOHL−Na) to enhance the durability of sodium metal anode during reduplicative plating/stripping processes. The inorganic components with high mechanical strength and strong sodiophilicity demonstrate optimized ionic conduction efficiency and dendrite inhibition ability. Simultaneously, the organic component contributes to the formation of a dense and elastic membrane structure, preventing fracture and delamination issues during volume fluctuations. The symmetrical batteries of IOHL−Na achieve stable cycling over 2000 hours with an extremely low voltage hysteresis of around 15.8 mV at a high current density of 4 mA cm⁻². Moreover, the Na−O₂ batteries sustain exceptional long-term stability and impressive capacity retention, exploiting a promising approach for constructing durable SEI and dendrite-free sodium metal anodes.     

Controlled hydrothermal growth and up-conversion emission of NaLnF(4) (Ln = Y, Dy-Yb)

The controlled hydrothermal preparation of NaYF(4) as both cubic and hexagonal phase types with specific associated morphologies, nanospheres and microtubes, respectively, has been achieved in the absence of organic solvents. The hexagonal NaYF(4) compound can be prepared in novel microtubular form and directly co-doped with Yb(3+)/Er(3+) ions. When excited by infrared light of 980 nm, these hexagonal NaYF(4) microtubes display strong green up-conversion emission, which was much more intense than that of cubic NaYF(4) or hexagonal NaYF(4) nanoparticles. Other related hexagonal-prismatic microtubes of NaLnF(4) (Ln = Dy-Yb) were also synthesized. A growth mechanism for the microtubes is proposed. In general, the diameter of the hexagonal NaLnF(4) microtubes is strongly dependent on the Ln(3+) size and increases as the rare-earth ionic radius decreases.     

氨气还原氮化法制备有序介孔TiN粉体及其电化学性能

以四氯化钛为原料,嵌段共聚物P123(PEO_(20)-PPO_(70)-PEO_(20))为模板剂,氰胺为稳定剂,采用非水解溶胶-凝胶法制备有序介孔TiO_2粉体,再经氨气还原氮化处理得到有序介孔TiN粉体.利用广角/小角X射线衍射、电子显微镜和N_2气吸-脱附等对TiN粉体的结构进行了表征,并通过循环伏安和充放电测试表征了电化学性能.结果显示,该粉体为高纯立方TiN相,呈球形颗粒状,具有有序介孔结构,比表面积高达97 m~2/g.在不同扫描速率下循环伏安曲线均呈类矩形,根据电流密度为50 m A/g时的恒流充放电(GCD)曲线计算比电容为233 F/g,且经2000次充放电循环后比容量仍保持90%以上,在功率密度为0.1 k W/kg时能量密度高达65 W·h·kg~(-1).     

A sensitive tetraphenylethene-based fluorescent probe for Zn2+ ion involving ESIPT and CHEF processes

A new tetraphenylethene-based fluorescent probe 2-(quinolin-8-yliminomethyl)-4-triphenylvinyl-phenol (HL) for detecting Zn²⁺ ion through the excited state intramolecular proton transfer (ESIPT) and chelation enhanced fluorescence (CHEF) processes has been designed and synthesized. The results show that HL emits relatively strong blue fluorescence at 460 nm without Zn²⁺ ion, however, probe HL displays highly pink fluorescent emission at 600 nm when adding Zn²⁺ ion. The fluorescent emission of HL appears an extremely large Stokes shift, which effectively reduces the interference of background signal. The limit of detection of HL for Zn²⁺ ion can reach to 9.0 × 10^–8 M.     

Electrochemical detection of short sequences related to the hepatitis B virus using MB on chitosan-modified CPE

A novel electrochemical DNA biosensor based on methylene blue (MB) and chitosan-modified carbon paste electrode (CCPE) for short DNA sequences and polymerase chain reaction (PCR) amplified real samples related to the hepatitis B virus (HBV) hybridization detection is presented. Differential pulse voltammetry (DPV) was used to investigate the surface coverage and hybridization event. The decrease in the peak current of MB, an electroactive label, was observed upon hybridization of probe with the target. Numerous factors affecting the target hybridization and indicator binding reaction are optimized to maximize the sensitivity.     

新型聚(酰胺-脲-酰亚胺)反渗透复合膜的稳定性

通过二次界面聚合法制备了一种新型的聚(酰胺-脲-酰亚胺)反渗透复合膜.将常规二元胺——间苯二胺(MPD)与关键功能单体5-异氰酸酯基-异肽酰氯(ICIC)通过界面聚合得到MPD-ICIC初生态基膜,再与关键功能单体N,N'-二甲基间苯二胺(DMMPD)经二次界面聚合制得聚(酰胺-脲-酰亚胺)反渗透复合膜.采用傅里叶变换红外光谱和X射线光电子能谱分析膜活性层的化学结构,评价膜的分离性能,在此基础上采用分子动力学模拟方法从微观角度分析二次聚合膜的稳定性.     

超高效液相色谱-串联质谱法测定畜禽毛发中利巴韦林及其代谢物

建立了一种测定畜禽毛发中利巴韦林及其代谢物1H-1,2,4-三氮唑-3-甲酰胺(TCONH2)残留的检测方法。1%十二烷基硫酸钠清洗毛发,2%甲酸-甲醇(2:98,V/V)溶液提取,13C-利巴韦林(13CRBV)内标法定量,乙二胺-N-丙基硅烷(PSA)和十八烷基硅烷(C18)基质分散净化,Agilent ZORBAX SB-Aq色谱柱分离,电喷雾串联质谱多反应监测模式测定。利巴韦林和TCONH2在毛发中线性关系良好(R^2>0.99)在2,10,100μg/kg3个添加水平下利巴韦林和代谢物TCONH2的回收率分别为101.5%~108.5%和98.5%~101.5%相对标准偏差均小于7%,检出限和定量限分别为0.2μg/kg和0.5μg/kg。该方法适合于畜禽毛发中违禁抗病毒药物利巴韦林及其代谢物TCONH2的测定。     

Realizing Complete Solid-Solution Reaction in High Sodium Content P2-Type Cathode for High-Performance Sodium-Ion Batteries

P2-type layered oxides suffer from an ordered Na⁺/vacancy arrangement and P2→O2/OP4 phase transitions, leading them to exhibit multiple voltage plateaus upon Na⁺ extraction/insertion. The deficient sodium in the P2-type cathode easily induces the bad structural stability at deep desodiation states and limited reversible capacity during Na⁺ de/insertion. These drawbacks cause poor rate capability and fast capacity decay in most P2-type layered oxides. To address these challenges, a novel high sodium content (0.85) and plateau-free P2-type cathode-Na_0.85Li_0.12Ni_0.22Mn_0.66O₂ (P2-NLNMO) was developed. The complete solid-solution reaction over a wide voltage range ensures both fast Na⁺ mobility (10⁻¹¹ to 10⁻¹⁰ cm² s⁻¹) and small volume variation (1.7 %). The high sodium content P2-NLNMO exhibits a higher reversible capacity of 123.4 mA h g⁻¹, superior rate capability of 79.3 mA h g⁻¹ at 20 C, and 85.4 % capacity retention after 500 cycles at 5 C. The sufficient Na and complete solid-solution reaction are critical to realizing high-performance P2-type cathodes for sodium-ion batteries.     

Synthesis of PANI and Study of Morphology in the Process of Polymerization

The polyaniline micro/nanostructure was prepared by a self‐assembly process with molybdic acid as dopants in the presence of ammonium persulfate as the oxidant. It was found that the morphology of PANI micro/nanostructure was affected by the concentration of the dopant, that is, the morphology of PANI changed from nanofibers to co‐existence of nanofibers and microspheres as the molar ratio of molybdic acid to aniline varied from 0.01 to 1.5. Under the same condition it was also found that the conductivity value of PANI enhanced from 4.58×10^?3 S·cm^?1 to 3.8×10^?1 S·cm^?1. The structure of PANI was characterized by FTIR and XRD which confirmed the presence of the molybdic acid in the PANI. The electrochemical characteristics of the PANI nanofibers were investigated by means of cyclic voltammetry. The morphology of PANI in the process of polymerization was characterized by SEM. It was found that when the molar ratio of molybdic acid to aniline was 0.3, the morphology of PANI was co‐existence of nanofibers and microspheres and the formation of microspheres was ahead of the nanofibers.