采用一步水热法合成了棒状NiCo_2O_4前驱体,并通过调节水热反应过程中碳源(葡萄糖)的加入量以及后续热处理条件(气氛、温度)得到了一系列不同的NiCo_2O_4及NiCo_2O_4@C产物,并对这些产物的结构、形貌及电化学储锂性能进行了测试.结果表...采用一步水热法合成了棒状NiCo_2O_4前驱体,并通过调节水热反应过程中碳源(葡萄糖)的加入量以及后续热处理条件(气氛、温度)得到了一系列不同的NiCo_2O_4及NiCo_2O_4@C产物,并对这些产物的结构、形貌及电化学储锂性能进行了测试.结果表明,适当的葡萄糖加入量(0.5 g)配合合理的煅烧条件(400℃,氮气气氛)可以获得倍率性能和循环稳定性兼具的NiCo_2O_4@C纳米复合材料.在100 m A/g的电流密度下,该材料的首次充/放电比容量为634.1/767.2 m A·h/g,对应的库仑效率为82.7%,5周后的放电比容量为650.1 m A·h/g,容量保持率为84.74%,且在300 m A/g的高电流密度下可逆比容量仍可保持在225.9m A·h/g.展开更多
液相合成法具有传热、传质快,材料粒径、形貌可控等优点,被广泛应用于各类材料制备领域。本文综述了共沉淀法、溶剂热法、sol-gel法合成磷酸铁锂正极材料的过程、原理和研究进展,并进行了对比和总结:纳米化、高比表面积、碳包覆,可以解...液相合成法具有传热、传质快,材料粒径、形貌可控等优点,被广泛应用于各类材料制备领域。本文综述了共沉淀法、溶剂热法、sol-gel法合成磷酸铁锂正极材料的过程、原理和研究进展,并进行了对比和总结:纳米化、高比表面积、碳包覆,可以解决电子电导率低和锂离子扩散速率慢所导致的倍率性能差的问题,是液相法合成的基本要求。共沉淀法有利于合成密堆积的球形形貌,获得高振实密度的材料,可以提高材料的能量密度。溶剂热法有利于合成大(010)面的材料,缩短锂离子扩散的距离,提高材料的倍率性能。Solgel法可以达到分子级别的混合,有利于制备成分均匀、原位碳包覆的材料。使用高电子电导率和离子电导率的材料,可以提高Li Fe PO4的倍率性能。相对固相法,寻找合成时间短、流程短、成本低的产业化方法,推动液相法在原理、工艺上的发展和进步是研究的方向。展开更多
Biocompatible carbon-spheres-based nanocomposites exhibit great potential in biomedical and clinical applications. In this contribution we report the first green photochemical synthesis of carbon spheres through in-si...Biocompatible carbon-spheres-based nanocomposites exhibit great potential in biomedical and clinical applications. In this contribution we report the first green photochemical synthesis of carbon spheres through in-situ enwrapping around silver nanoparticles(CS–Ag NPs). Since mesoporous carbon spheres can provide the location for combining Ag NPs and other agents, one-step synthesis of glutathione-stabilized CS–Ag NPs could be readily realized by photoreduction. TEM characterization of CS–Ag NPs nanocomposites illustrates that Ag NPs were superbly wrapped inside the carbon spheres and also adhered to the surfaces of the carbon spheres. These porous CS–Ag NPs show excellent fluorescence and effective antibacterial efficiency, exhibiting ideal lengthened activities against Escherichia coli and Staphylococcus aureus compared with bare Ag NPs. The relevant rationale behind it could be attributed to the fact that CS–Ag NPs nanocomposites can provide some excellent niches for the durable and slow release of silver ions. This raises the possibility of promising applications of CS–Ag NPs nanocomposites as excellent antibacterial agents for the efficient monitoring of some disease-related bacteria.展开更多
文摘采用一步水热法合成了棒状NiCo_2O_4前驱体,并通过调节水热反应过程中碳源(葡萄糖)的加入量以及后续热处理条件(气氛、温度)得到了一系列不同的NiCo_2O_4及NiCo_2O_4@C产物,并对这些产物的结构、形貌及电化学储锂性能进行了测试.结果表明,适当的葡萄糖加入量(0.5 g)配合合理的煅烧条件(400℃,氮气气氛)可以获得倍率性能和循环稳定性兼具的NiCo_2O_4@C纳米复合材料.在100 m A/g的电流密度下,该材料的首次充/放电比容量为634.1/767.2 m A·h/g,对应的库仑效率为82.7%,5周后的放电比容量为650.1 m A·h/g,容量保持率为84.74%,且在300 m A/g的高电流密度下可逆比容量仍可保持在225.9m A·h/g.
文摘液相合成法具有传热、传质快,材料粒径、形貌可控等优点,被广泛应用于各类材料制备领域。本文综述了共沉淀法、溶剂热法、sol-gel法合成磷酸铁锂正极材料的过程、原理和研究进展,并进行了对比和总结:纳米化、高比表面积、碳包覆,可以解决电子电导率低和锂离子扩散速率慢所导致的倍率性能差的问题,是液相法合成的基本要求。共沉淀法有利于合成密堆积的球形形貌,获得高振实密度的材料,可以提高材料的能量密度。溶剂热法有利于合成大(010)面的材料,缩短锂离子扩散的距离,提高材料的倍率性能。Solgel法可以达到分子级别的混合,有利于制备成分均匀、原位碳包覆的材料。使用高电子电导率和离子电导率的材料,可以提高Li Fe PO4的倍率性能。相对固相法,寻找合成时间短、流程短、成本低的产业化方法,推动液相法在原理、工艺上的发展和进步是研究的方向。
基金supported by the National Basic Research Program of China(2010CB732404)the National Natural Science Foundation of China(81325011,21327902,21175020)+1 种基金the National High Technology Research and Development Program of China(2012AA022703)the Suzhou Science&Technology Major Project(ZXY2012028)
文摘Biocompatible carbon-spheres-based nanocomposites exhibit great potential in biomedical and clinical applications. In this contribution we report the first green photochemical synthesis of carbon spheres through in-situ enwrapping around silver nanoparticles(CS–Ag NPs). Since mesoporous carbon spheres can provide the location for combining Ag NPs and other agents, one-step synthesis of glutathione-stabilized CS–Ag NPs could be readily realized by photoreduction. TEM characterization of CS–Ag NPs nanocomposites illustrates that Ag NPs were superbly wrapped inside the carbon spheres and also adhered to the surfaces of the carbon spheres. These porous CS–Ag NPs show excellent fluorescence and effective antibacterial efficiency, exhibiting ideal lengthened activities against Escherichia coli and Staphylococcus aureus compared with bare Ag NPs. The relevant rationale behind it could be attributed to the fact that CS–Ag NPs nanocomposites can provide some excellent niches for the durable and slow release of silver ions. This raises the possibility of promising applications of CS–Ag NPs nanocomposites as excellent antibacterial agents for the efficient monitoring of some disease-related bacteria.
