Ai Xinping

Hydrogen production from catalytic hydrolysis of sodium borohydride solution using nickel boride catalyst

Abstract A highly stable and active nickel boride catalyst (NixB) was prepared and tested for the catalytic hydrolysis of alkaline NaBH4 solution. It was found that after heat treatment at 150°C in vacuum the NixB catalyst shows greatly enhanced catalytic activity and operational stability. In the experimental conditions, the hydrolysis reaction can produce 6.75 wt % hydrogen at 45°C and >4.0 wt % hydrogen even at room temperatures, exhibiting much higher hydrogen storage capacity than currently used alloys for hydrogen storage. Since the NixB catalyst is inexpensive and easy to prepare, it is feasible to use this catalyst in the construction of practical hydrogen generators for portable and in situ applications.

Chemiluminescence determination of thiourea using tris (1,10-phenanthroline)-ruthenium (II) KMnO4 system

The light emission produced by thiourea in oxidation process by permanganate in acidic solution in the presence of Ru(phen)23+ is used to determine 1.0×10−5 −1.0×10−5 mol/L thiourea. The limit of detection is 9.8×10−9 mol/L and the relative standard deviation is 1.1% for a 1.0×10−5 mol/L thiourea solution (n=10). The method was applied satisfactorily to the determination of thiourea.

Discussion on the mechanism of sodium storage of different structural types of carbon material

Because of its rich resources and cost advantages, sodium-ion battery has attracted increasing attention in the field of large-scale energy storage. Similar to the lithium-ion battery anode, carbon materials are the most widely studied sodium storage anode materials. However, carbon materials have diverse structures relied on the treatment conditions, resulting in differences in the properties of sodium storage and even the different sodium storage mechanisms. In order to study the relationship between the carbon structure and its storage behavior, this paper comprehensively analyzes the structural characteristics and sodium storage behavior of different carbon materials, discusses the possible electrochemical mechanism, and makes possible analysis of some existing controversial areas. And this paper can also provide a reference for the development of high performance carbon-based sodium storage materials.

A brief analysis on the technology development of the EV batteries

With an eye to the future commercialization of all-electric vehicles, the realizable targets for the near-term, middle-term and long-term developments of power batteries are proposed on the analysis of the state-of-the-art technologies for electrochemical batteries. In view of the battery systems possibly satisfying the performance targets on different stages, a technology roadmap is put forward with an emphasis on the individual and combined contributions of cathode and anode materials to the specific energies of the power batteries including Li-ion and Li-S batteries. Also, possible strategies are discussed for development of advanced materials and technologies for the power batteries. Finally, the safety issue on lithium-ion power batteries is analyzed together with a brief instruction of the safety-enhancing technologies.

One step ball-milling synthesis of LiFePO4 nanoparticles as the cathode material of Li-ion batteries

A one-step synthetic method was used to synthesize Olivline LiFePO4 powders by direct ball milling the stoichiometric mixture of Fe, Li3PO4, and FePO4 powders. XRD and TEM measurements revealed that the as-prepared LiFePO4 powder have a homogeneous Olivine structure and a uniform size distribution of ca. 50 nm. Based on this material, a LiFePO4/C composite was prepared and used for the cathode material of Li-ion batteries. The charge-discharge experiments demonstrated that the LiFePO4/C composite material has a high capacity of 132 mAh/g at 0.1 C and a quite high-rate capability of 95 mAh/g at 1 C. This new ball-milling method may provide a completely green synthetic route for preparing the materials of this type cost-effectively and in large volume.

Al 3+ 掺杂0.5Li 2 MnO 3 -0.5LiCo 1/3 Ni 1/3 Mn 1/3 O 2 正极材料的研究

采用聚合热解法制备了掺入3% Al 3+ 的富锂锰基Li[Li 0.2 Co 0.13 Ni 0.13 Mn 0.51 Al 0.03 ]O 2 材料, 经过X射线衍射(XRD)、扫描电镜(SEM)实验表明, 掺入3%Al 3+ 样品仍然保持层状结构, 没有观察到杂质相的存在。在2.0~4.8 V范围内进行恒流充放电测试表明, 掺Al 3+ 样品在30 mA/g的电流密度下, 首周充放电比容量可达349.1和303.8 mAh/g(首次库仑效率87%); 在100 mA/g的电流密度下, 100次循环后, 容量保持率为91.7%, 显示出高的循环稳定性。这些结果表明掺杂Al 3+ 能够在一定程度上提高富锂氧化物材料层状结构的稳定性, 为发展高容量和高稳定性正极材料提供一种新途径。采用聚合热解法制备了掺入3% Al 3+ 的富锂锰基Li[Li 0.2 Co 0.13 Ni 0.13 Mn 0.51 Al 0.03 ]O 2 材料, 经过X射线衍射(XRD)、扫描电镜(SEM)实验表明, 掺入3%Al 3+ 样品仍然保持层状结构, 没有观察到杂质相的存在。在2.0~4.8 V范围内进行恒流充放电测试表明, 掺Al 3+ 样品在30 mA/g的电流密度下, 首周充放电比容量可达349.1和303.8 mAh/g(首次库仑效率87%); 在100 mA/g的电流密度下, 100次循环后, 容量保持率为91.7%, 显示出高的循环稳定性。这些结果表明掺杂Al 3+ 能够在一定程度上提高富锂氧化物材料层状结构的稳定性, 为发展高容量和高稳定性正极材料提供一种新途径。

Investigation of Ru （ phen ）3^2＋-Hydrazine-Ce（IV） Chemiluminescence System and Its Analytical Application

It was observed that hydrazine could enhance the chemiluminescence (CL) intensity of tris-(1,10-phenanthroline) ruthenium(II) (Ru (phen)32+)-Cerium (IV) (Ce(IV)) system, based on which, a novel CL system, Ru(phen)32+-Hydrazine-Ce(IV), was established. This CL system was investigated and employed to detect hydrazine. Under the optimum experimental conditions, the linear range and detection limit of the proposed method are 2.0×10−6–2.0×10−3 g ·L−1 and 1.8×10−6 g·L−1, respectively. For 1.5×10−5, 1.5×10−4 and 1.2×10−3 g·L−1 hydrazine, the relative standard deviation (RSD) is 2.9%, 2.2% and 3.1%, respectively (n=11). The proposed method has been used to detect the content of hydrazine in the synthetic samples with satisfactory results.

Sensitive determination of DNA by RLS enhancement of metal ions

The interactions between metal ions and DNA have been studied by the resonance light scattering (RLS) spectra. In the acidic condition, the RLS signals of metal ions, especially the transition metal ions in group IB and IIB, were increased by DNA. And it is found that the enhancement of RLS signals is linear to the concentration of DNA, so the RLS method for DNA determination was proposed in the presence of Cu2+. On the optimum conditions, the linear range and the detect limit of ctDNA is 4×10−8–4×10−6 g· mL−1 and 1. 13×10−8 g·mL−1, respectively. The proposed method is successfully applied to determine the extracted plasmid DNA ofBacillus subtilis DB104.