CAJ | 학술논문

采用铬酸溶液对碳纳米管进行后处理,旨在修饰碳纳米管的表面形态及改变碳纳米管的表面结构,进一步增强碳纳米管的场发射特性.铬酸溶液后处理与传统以硝酸后处理的厅法不同之处在于,铬酸溶液可以更有效率地与非品质碳及碳纳米管发生化学反应.可以预期碳纳米管经过铬酸溶液处理后,碳纳米管的表而形态、化学组成及场发射特性会产生很大的变化.场发射的数据显示,经铬酸溶液处理20 min的碳纳米管场发射电流比未经过铬酸溶液处理的场发射电流有明显的增加.然而,长时间的铬酸溶液处理也会降低碳纳米管场发射特性.经铬酸溶液处理20min的碳纳米管场发射电流增强原因主要为适度的铬酸溶液处理可以改变碳纳米管的表面形态,使碳管的表面密度增大、场发射功函数降低.但过长时间的铬酸溶液后处理,又会造成碳纳米管数目减少及表面结构受到损害,导致碳纳米管场发射特性变差.
채용락산용액대탄납미관진행후처리,지재수식탄납미관적표면형태급개변탄납미관적표면결구,진일보증강탄납미관적장발사특성.락산용액후처리여전통이초산후처리적청법불동지처재우,락산용액가이경유효솔지여비품질탄급탄납미관발생화학반응.가이예기탄납미관경과락산용액처리후,탄납미관적표이형태、화학조성급장발사특성회산생흔대적변화.장발사적수거현시,경락산용액처리20 min적탄납미관장발사전류비미경과락산용액처리적장발사전류유명현적증가.연이,장시간적락산용액처리야회강저탄납미관장발사특성.경락산용액처리20min적탄납미관장발사전류증강원인주요위괄도적락산용액처리가이개변탄납미관적표면형태,사탄관적표면밀도증대、장발사공함수강저.단과장시간적락산용액후처리,우회조성탄납미관수목감소급표면결구수도손해,도치탄납미관장발사특성변차.
A simple method is described to functionalize the surface and to modify the structures of multi-walled carbon nanotubes (MWCNTs) grown on silicon substrates using chromium trioxide (CrO3) solution. Unlike nitric acid (HNO3) used in the conventional post-treatment for MWCNTs, the chemical reaction with CrO3 involves amorphous carbon and the carbon nanotubes themselves. It is expected that the surface morphology, chemical composition, and field emission of MWCNTs should be significantly changed after CrO3 solution treatment. The results showed that after 20 min of CrO3 solution treatment, the emission currents were enhanced compared with the as-grown MWCNTs. However, extended treatment over 20 min was found to degrade the field emission properties of the film. The enhancement in field emission after 20 min of CrO3 solution treatment can be ascribed to the modification of surface morphology, the increase in surface density of MWCNTs, and the lowering of the work function. Prolonged CrO3 treatment dissolves MWCNTs and thus results in a decrease in field emission.