~(67)Ga-C_(60)(OH)_x标记条件的研究

用^67Ga标记了水溶性富勒烯衍生物富勒醇（C60（OH）x）。研究了反应时间、温度、pH值、C60（OH）x的质量浓度等对标记率的影响。研究结果表明，反应时间在3-60min时对标记率影响不大；反应温度对标记率基本无影响；pH值大于12后，标记率较低；C60（OH）x的质量浓度高于5μg/μL时，标记率均在94%以上。稳定性研究结果表明，标记后稀释与不稀释的溶液在放置200h后，其放化纯度都达90%以上。     

废弃口罩基ZIF-8/Ag/TiO2复合材料的制备及其光催化降解染料性能

针对废弃口罩和印染废水处理难题,利用金属有机骨架ZIF-8高度可调的孔径、大的比表面积、优异的吸附和光催化活性,基于化学共沉淀法和煅烧技术制备出ZIF-8/Ag/TiO₂异质结,并将其负载到废弃的口罩上。对颗粒物和口罩复合材料的形貌、结构、比表面积、键合状态、能带结构和热稳定性进行了分析,测定了吸附、光催化降解亚甲基蓝和刚果红染料性能。研究结果表明:较原始口罩,废弃口罩基ZIF-8/Ag/TiO₂复合材料的吸附、可见光光催化降解亚甲基蓝染料能力分别提高了12.9倍和4.8倍,且可多次重复使用;较ZIF-8和ZIF-8/TiO₂,ZIF-8/Ag/TiO₂异质结吸附能力和可见光光催化活性增强。Ag掺杂ZIF-8/ZnO与C、N掺杂TiO₂使得ZIF-8/Ag/TiO₂异质结带隙变窄,且有孔的中空结构能够更加充分地吸收可见光。     

ZIF-8/TiO2纳米复合材料的制备及光生阴极保护性能

采用逐步生长法在TiO₂纳米管阵列上负载ZIF-8纳米颗粒制得ZIF-8/TiO₂纳米复合材料。通过XRD、SEM、UV-vis DRS等手段对材料的结构、形貌和光响应进行表征,并在开/闭可见光下对材料进行光电化学测试。结果表明,ZIF-8/TiO₂纳米复合材料光吸收扩展到可见光区;将其作为光阳极与304不锈钢耦合后,光照条件下阴极保护电位可降至-0.92 V,比Ti O₂纳米管阵列降低约180 mV,且在较长时间内可对304不锈钢表现出优异的光生阴极保护性能。     

SWRH67A、SWRH72A盘条的试制

介绍SWRH6 7A、SWRH72A盘条的试制过程 :采用氧气顶吹转炉和钢包底吹氩搅拌工艺炼钢 ,用R5m连铸机轧制 110mm× 110mm方坯 ,经高速线材轧机控制轧制工艺生产出盘条。指出拉碳法、保护浇注、控冷等措施的应用可有效保证产品质量 ,使金相组织、晶粒度、脱碳层深度、非金属夹杂物级别等指标符合日本及相应标准要求。产品经用户使用 ,不经热处理可一次由 5 .5mm拉拔至 1.8mm ,各项性能满足使用要求     

Ethene/ethane mixture diffusion in the MOF sieve ZIF-8 studied by MAS PFG NMR diffusometry

The adsorption and diffusion of ethene/ethane mixtures is explored by ¹H and ¹³C MAS NMR spectroscopy and by the combination of PFG NMR with magic-angle spinning (MAS PFG NMR). Some indication for a preferential adsorption of the molecules close to the methyl-groups of the imidazole-rings was found, however no evidence for structural changes upon adsorption of an ethene/ethane mixture.MAS PFG NMR allows an individual but simultaneous observation of both molecules in adsorbed state and as well as in the gas phase. The intracrystalline MAS PFG NMR diffusivities are in consistent agreement with our previous data obtained by IR microscopy. Our consideration includes the loading dependence and the correlation of self-diffusion with transport diffusion by accounting for the influence of the thermodynamic factor.The diffusion selectivity is determined to D_ethene:D_ethane = 5.5 at a loading of four molecules per cavity. The higher mobility of ethene can be rationalized by its smaller size compared to ethane. This conclusion is validated by the measured activation energies for diffusion which are considerably higher for ethane. On the other hand, differences in the guest-host interaction between the saturated and non-saturated molecules can be excluded as possible reason for the different diffusivities.     

ZIF-67-derived Mn doped Co9S8 supported on N-Enriched porous carbon polyhedron as an efficient electrocatalyst for oxygen evolution reaction

Rational design of efficient oxygen evolution reaction (OER) electrocatalysts plays a significant role in various applications like water splitting and metal-air batteries. Simultaneous modulation of geometric and electronic structure is a promising strategy for boosting the electrocatalytic active of OER catalysts. Herein, a novel type of Mn doped Co₉S₈ supported on N-enriched porous carbon polyhedron composite material (Mn–Co₉S₈/NC) is constructed via absorption-pyrolysis-sulfurization treatment of Zeolitic-imidazolate frameworks (ZIF-67). ZIF-67 derived N-enriched porous carbon polyhedron serves as the porous skeleton for anchoring numerous Co₉S₈ nanoparticles. The results confirm that the incorporation of Mn in Co₉S₈/NC can improve the degree of graphitization compared with Co₉S₈/NC, implying the enhancement of the conductivity. Meanwhile, the incorporation of Mn can lead to electronic modulation of Co species to bump up the intrinsic activity of active site in Mn–Co₉S₈/NC. Due to the synergistic effect of Mn, Co₉S₈ and porous carbon structure, the specific surface area and electronic structure are optimized, endowing the maximum utilization of active sites. The Mn–Co₉S₈/NC electrocatalyst exhibits superior OER activity with the overpotential of 286 mV at current density of 10 mA cm⁻² in 1.0 M KOH electrolyte. This work provides prospective insights into the synergistic coupling of geometric and electronic structure of Metal-Organic Frameworks (MOFs) material for efficient electrocatalysts.     

Self-assembly of metal-organic framework onto nanofibrous mats to enhance proton conductivity for proton exchange membrane

Constructing consecutive proton-conducting nanochannels and optimizing nanophase-separation within proton exchange membrane (PEM) was of guiding significance for improving proton transfer. Metal organic framework (MOF), as a novel and functional material had drawn increasing attention in the research of proton PEM because of its flexible tunability and designability. Herein, a novel MOF-based nanofibrous mats (NFMs) were prepared by the self-assembly of zeolitic imidazole framework-67 (ZIF-67) onto polyacrylonitrile (PAN) NFMs. Subsequently, the ZIF-67 NFMs were incorporated into Nafion matrix to prepare ZIF-67@Nafion composite membrane which aimed at constructing consecutive proton-conducting channels. Especially, the acid–base pairs between N–H (ZIF-67 NFMs) and –SO₃H (Nafion) could promote the protonation/deprotonation and subsequent proton leaping via Grotthuss mechanisms. As expected, the ZIF-67@Nafion-5 composite membrane showed a promising proton conductivity of 288 mS/cm at 80 °C and 100% RH, low methanol permeability of 7.98 × 10⁻⁷ cm²s⁻¹, and superior power density of 298.68 mW/cm² at 80 °C and 100% RH. In addition, the resulting composite membrane exhibited considerable enhancement in thermal stability and dimensional stability. This promising strategy provided a valuable reference for designing high-performance PEMs.     

ZnS,Fe, and P co-doped N enriched carbon derived from MOFs as efficient electrocatalyst for oxygen reduction reaction

Exploring electrocatalysts with low cost and excellent performance for oxygen reduction reaction is still a significant challenge. In this paper, we introduce a novel strategy to fabricate ZnS, Fe, and P co-doped N enriched carbon (ZnFeSP/NC) via the direct carbonization of PVP/ZIF-8 combined with absorption, sulphurization, and phosphorization processes. The as-synthesized ZnFeSP/NC was used as electrocatalyst for oxygen reduction reaction (ORR). We explored the influence of Fe, S, and P elements on the ORR activity of the catalysts. It can be found that ZnS nanoparticles were formed and attached on the surface of the ZnFeSP/NC nanoparticles. α-Fe and P element were well dispersed on ZnFeSP/NC nanoparticles. Fe, S, and P element can highly enhance the ORR activity of the catalysts. Compared to Zn/NC, ZnFe/NC, and ZnFeS/CN, ZnFeSP/NC shows the optimal ORR performance with the half-wave potential of 0.859 V and a current density of 3.33 mA cm⁻² at −0.85 V. Furthermore, ZnFeSP/NC also exhibits excellent long-term operation stability, effectively avoiding any ORR performance decay.     

Emergent hierarchical porosity by ZIF-8/GO nanocomposite increases oxygen electroreduction activity of Pt nanoparticles

Hierarchically porous materials are promising as catalyst supports in fuel cells and batteries as they increase overall mass transfer and active site density. In this work, a hierarchically porous catalyst support for oxygen reduction reaction (ORR) in acidic media has been developed by a bottom-up approach. Graphene oxide (GO) was introduced during synthesis conditions of zeolitic imidazolate framework-8 (ZIF-8) to produce hybrid material of ZIF-8/GO. Successful nanocomposite formation was realized by preserved crystallinity and chemical interaction between species as revealed by X-ray diffraction and Fourier transform infrared spectroscopy. Introduction of GO and pyrolysis of resulting hybrid structure causes emergence of disordered meso/macropores with an accompanying increase in pore volume as revealed by N₂ sorption experiments. Pt nanoparticle deposition on pyrolyzed hybrid material by polyol method results in electrocatalyst Pt/NC-1, which shows greatly improved mass activity (182 vs 86 A g⁻¹_Pt) and specific activity (467 vs 186 μA g⁻¹_Pt) at 0.8 V for ORR against reference electrocatalyst Pt/r-GO and improved specific activity against Pt/C.