Order effect of Au nanoparticles on forest SWCN studied by NEXAFS

JOSE MARTIN RAMALLO LOPEZ; FÉLIX GREGORIO REQUEJO; ZHANG, L.; DANIEL RESASCO

Camerino

Congreso; XAFS 14 Conference; 2009

Aligned Single Wall Carbon Nanotubes (SWCN) have a great interest because of their potential applications in many fields [1]. In order to optimize their use in different applications in catalysis, nanoelectronics, optics or nanobiotechnology, it becomes interesting to functionalize their surface with metal nanoparticles (NPs). However, attention should be paid to the order of the CNT after the addition of the NPs. In this work, we studied the order of vertical and horizontal aligned-SWCN functionalized with gold NPs by two different methods through carbon K-edge XANES spectroscopy [2] using linearly polarized x-rays. Gold NPs were introduced to the SWCN by evaporation of gold and by dipping the NPs in a solution of thiol-capped Au NPs Through the peaks attributed to the dipolar transition of core level 1s electrons into C-C * and C-C * states in the conduction band we found that a decrease in the order of the vertical-aligned SWCN after the addition of gold by both methods takes place. However, the order of the SWCN can be recovered after a fast annealing. No such effect is observed for horizontal-aligned SWCN which may indicate a less strong interaction of the side walls with the metal NPs