碳纳米管优异的物理性质和可调的化学组成使其拥有广泛的应用前景。采用低温过程在碳骨架中引入磷原子预期带来可调的化学特性。本研究采用170℃下水热处理碳纳米管-磷酸混合物获得磷掺杂的碳纳米管。磷掺杂的碳管的磷含量为1.66%,比表面积为132m~2/g,热失重峰在纯氧环境下提升至694℃。当掺磷碳纳米管用于氧还原反应时,其起始电位为-0.20 V,电子转移数为2.60,反应电流显著高于无掺杂的碳纳米管。当其用作锂硫电池正极导电材料时,电极的起始容量为1106 m Ah/g,电流密度从0.1 C提升至1 C时容量保留率为80%,100次循环的衰减率为每圈0.25%。
The many uses of carbon nanotubes (CNTs) depend not only on their intrinsic physical properties,but also on theirtunable chemical components. Exploring a low-temperature method for the incorporation of phosphorus atoms in the carbon frame-work is expected to change the chemical properties of CNTs. Here,phosphorus-functionalized CNTs (PCNTs) were prepared by the direct hydrothermal treatment of a CNT-H3PO4 mixture at 170 ℃ .The PCNTs had a high phosphorus content o f 1 .66 a t% ,a spe-cific surface area of 132 m2 ·g-1,and an improved thermal stability with a weight loss peak at 694 ℃ during oxidation in pure o x y -gen. They showed good electrocatalytic activity for the oxygen reduction reaction with an onset potential of 0.20 V vs Hg/Hg 2Cl2 , an electron transfer number of 2.60,and a larger current density as well as improved cyclic stability compared with pristine CNTs. PCNTs were also used as conductive scaffolds for the cathode in lithium-sulfur batteries. The cathode delivered an initial discharge capacity of 1 106 mAh·g-1,a capacity retention of 80% from 0.1 to 1.0 C,and a low decay rate of 0.25% per cycle during 100 cycles.