分光光度法对2,4,6—三氯苯肼的测定研究

在酸性条件下,2,4,6-三氯苯肼与碘酸钾反应生成碘,用分光光度法测定碘,从而间接测定2,4,6-三氯苯肼。     

硝酸肼还原反萃取分离镎/钚的研究

镎的提取和分离是国际后处理领域重点关注的研究课题之一。在Purex流程中,硝酸肼常被用来作为亚硝酸的清扫剂,此外,由于硝酸肼对Np(VI)和Pu(IV)的氧化还原反应具有选择性,理论上可以利用其反应速率上的差异来实现镎与铀钚的分离。为探索硝酸肼分离镎/钚工艺提供可行性,本文采用单级萃取设备研究了硝酸肼还原反萃Np和Pu的过程。通过研究硝酸浓度、硝酸肼浓度和反应温度对还原反萃过程的影响,确定了Np(VI)和Pu(IV)反萃动力学方程和表现活化能。进一步通过动力学方程得出硝酸肼还原反萃Np(VI)和Pu(IV)的半反应时间,并对Np(VI)/Pu(IV)分离过程的工艺进行了初步探索。     

天然橡胶环保改性剂ORA-100的应用

在橡胶产品的生产过程中,特别是轮胎生产过程中,须大量使用天然橡胶。这个过程中遇到的一个棘手问题就是在天然橡胶的停放过程中,生胶的门尼黏度会显著地升高,从而影响天然橡胶的加工性能,增加生产能耗。同时天然橡胶在塑炼,混炼、硫化等生产过程中会产生浓重的气味,这种气味不利于生产企业的环保要求,也不利于这些企业与周边居民的和睦关系。天然橡胶环保改性剂ORA-100以其特殊的性能,能够很好地解决这些问题,起到稳定天然橡胶的门尼黏度,改善生产操作环境(降低天然橡胶的臭味)、实现节能环保的作用。通过对这个材料的性能研究,介绍了它的一些独特的功能、作用机理和应用。     

Electrocatalytic oxidation of hydrazine at a Co(II) complex multi-wall carbon nanotube modified carbon paste electrode

The catalytic oxidation of hydrazine was investigated by a cobalt(II) bis (benzoylacetone) ethylenediimino multi wall carbon nanotube-modified carbon paste electrode (Co(II)BBAEDI-MWCNT-MCPE) as a highly sensitive electrochemical sensor. The effect of variables such as pH and modifier percent on cyclic voltammograms peak current was optimized. The modified electrode showed very efficient electrocatalytic activity for anodic oxidation of hydrazine in 0.1 M phosphate buffer solution (pH 7.0). Anodic peak potential of hydrazine oxidation at the surface of modified electrode shifts by about 500 mV toward negative values compared with that on the bare electrode. The diffusion coefficient and electron transfer coefficient of hydrazine were obtained using electrochemical approaches. The Co(II)BBAEDI-MWCNT-MCPE showed good reproducibility (RSD < 3.3%). The electrocatalytic current increased linearly with the hydrazine concentration in the range of 0.3–70.0 μM and detection limit was 0.1 μM. The effect of various interferences on the hydrazine peak current was studied. This method was applied to determine hydrazine in water samples.     

碱性蚀刻废液的综合利用-水合肼还原回收铜

研究了以水合肼为还原剂,回收碱性蚀刻废液中铜的方法。试验结果表明,最佳工艺条件为：水台肼用量3.5mL,反应时间40min,0．05mL催化剂LA和1．5mL催化剂LB,铜的收率为68．6％。回收锕后的碱性蚀刻废液可重复利用,用于配制新的蚀刻液,基本实现零排放,实现清洁生产。     

Enhancement of catalytic properties and durability in Ni–B–P/Ni foam for hydrazine electrooxidation

Hydrazine is a promising energy carrier of high power density, high theoretical cell voltage, and zero carbon emission to replace fossil fuel-dominated energy sources. Herein, we present a new Ni–B–P/NF catalyst for hydrazine electrooxidation by a facile electroless plating process. The Ni–B–P/NF catalyst exhibits remarkable catalytic activity (290 mA cm⁻² at 0.3 V) by combining merits of high intrinsic activity, large specific surface area, satisfactory conductivity, and lattice dislocation. Meanwhile, the Ni–B–P/NF catalyst provides excellent long-term durability (5000 s, 94.4%), which is at the leading level among the reported Ni-based electrocatalysts for hydrazine electrooxidation to date. It is found that the phosphorus-containing coating and its tight binding to the substrate contribute to the long-term durability of Ni–B–P/NF. XPS results and electron models are used to elucidate the electron transition mechanism of the Ni–B–P coating. This work presents a novel catalyst for hydrazine electrooxidation and demonstrates its promising application in energy storage and fuel cell systems.     

Metal organic framework derived trifunctional NiCoP electrode for continuous solar-driven energy-saving hydrogen generation

Water splitting is a sustainable and clean hydrogen-production technology, but driven either by solar energy with natural intermittent, or by power grid with high cost, which is not conductive to sustainable development. Additionally, the sluggish anodic oxygen evolution reaction (OER) remains a huge obstacle for efficient hydrogen production. Herein, an intersected nanosheets decorating micro-walls structure nickel-cobalt phosphide grown on Ni foam electrode (NiCoP/NF) is prepared, and displays good hydrogen evolution reaction (HER), excellent hydrazine oxidation reaction (HzOR) and enhanced NiCoP/NF//Zn battery capacity performance. Based on the trifunctional NiCoP/NF electrode, a continuous solar-driven energy-saving hydrogen generation is constructed. The solar cells drive the efficient hydrogen production and hydrazine degradation plus simultaneously charge the NiCoP/NF//Zn battery during the day; then the charged NiCoP/NF//Zn battery provide high output voltage to drive hydrogen generation and hydrazine degradation at night. The continuous solar-driven energy-saving hydrogen generation plus sewage treatment strategy exhibits a new way for clean and sustainable energy supply plus curbing environmental pollution.     

Aqueous hydrazine borane N2H4BH3 and nickel-based catalyst: An effective couple for the release of hydrogen in near-ambient conditions

Nickel-based bimetallic catalysts were screened using the sodium borohydride NaBH₄ hydrolysis and the aqueous hydrazine borane N₂H₄BH₃ dehydrogenation. A total of 22 bimetallic catalysts were synthesized according to an easy process while focusing on metals like Fe, Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt and Au. In the end, the bimetallic candidate Ni_87.5Pt_12.5 showed to be the most active and the most selective for the dehydrogenation of N₂H₄BH₃. At 70?°C, it is able to decompose N₂H₄BH₃ into 5.8 equivalents of H₂+N₂ in less than 12?min such as: N₂H₄BH₃?+?3H₂O?→?0.95 N₂?+?0.1 NH₃?+?B(OH)₃?+?4.85H₂. Durability and stability tests were also performed. In our conditions, Ni_87.5Pt_12.5 was found to suffer from small loss of performance because of an electronic evolution of the catalytic surface leading to modified sorption properties of the catalytic sites. Our main results are reported and discussed herein.     

Preparation and electrocatalytic application of high dispersed Pt nanoparticles/ordered mesoporous carbon composites

A simple approach for the synthesis of nanosized platinum particles supported on ordered mesoporous carbons (OMCs) was described. For the first time, we successfully used the positively charged poly-(diallydimethylammonium chloride, PDDA) to wrap OMCs and attached Pt nanoparticles (OMCs–PDDA/Pt) via electrostatic interaction. The obtained OMCs–PDDA/Pt nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electrochemical methods. TEM images reveal that the Pt nanoparticles with an average size of ∼2.88 nm are uniformly dispersed on the surface of OMCs–PDDA. The electrocatalytic behavior of OMCs–PDDA/Pt modified glassy carbon (GC) electrode was investigated by cyclic voltammetry, current–time and chronoamperometry methods using hydrazine as a redox probe. The electrochemical results indicate that the OMCs–PDDA/Pt exhibit a good electrocatalytic activity toward the oxidation of hydrazine than that of OMCs/Pt. All these electrochemical measurements confirm the fact that the OMCs–PDDA/Pt nanocomposites may have applications in biological and environmental sensors.