Laser-induced nanostructuration of vertically aligned carbon nanotubes coated with nickel oxide nanoparticles

Abstract

A versatile method is explored to decorate vertically aligned multi-walled carbon nanotubes (VACNTs) with NiO nanostructures. Multi-walled VACNTs are grown by plasma enhanced chemical vapor deposition and coated with NiO nanoparticles (NPs) by drop casting. After that, the system is submitted to nanosecond pulsed UV laser irradiation in atmospheric environment. Laser irradiation provokes rapid heatingmelting-cooling processes which lead to the recrystallization of NiO NPs on the outer walls of VACNTs. In this way, and depending on the laser fluence and the number of accumulated pulses, different nano-architectures such as continuous NiO coatings and spiny features on VACNTs are obtained. High resolution scanning and transmission electron microscopies and Raman spectroscopy, corroborated with photothermal simulations, suggest that the grown nanostructures are mainly created by the laserinduced high temperatures (photothermal mechanisms). However, the observed reconstruction of the outer graphitic shells of VACNTs point to the catalytic action of NiO NPs, probably induced by the direct action of the laser radiation.

Reactive laser synthesis of nitrogen-doped hybrid graphene-based electrodes for energy storage

“…The numerical calculations were done by means of COMSOL 5.2 software, using the H 2 O, GO and NiO thermophysical properties extracted from Refs. 44,46,49 For the sake of simplicity, the model uses rectangular-shaped GO flakes 1 µm in length and 1-10 nm in thickness (ca. 1-15 monolayers) and squared-shaped NiO NPs with 50 nm lateral size.…”

“…68 The formation of such GO-urea stacked assemblies in the aqueous target would increase their absorption to the laser radiation leading to the development of higher temperatures, and hence larger deposition rates and film thicknesses, as already observed (Table 1) that is ascribed to one-phonon (1P) scattering. 49 This fact could be related to the preferential orientation and larger size of the NiO domains in the continuous layer present in GO-NiO-Urea rather than in the rest of GO / NiO films, where smaller randomly oriented nanostructures are grown. GO broad bands appear around 900 -1800 cm -1 and 2300 -3400 cm -1 .…”

Laser Irradiation of Electrode Materials for Energy Storage and Conversion

“…Del Pino et al reported a stimulated temperature profile showing a rapid rise to almost 1,200 K within a timescale of 10 À8 s on a laser-irradiated NiO-coated carbon nanotubes (CNTs) array. 32 This temperature is sufficient to drive the synthesis of a wide range of nanomaterials (Figure 2C). 20,29 Moreover, the recrystallization and phase transformation of many materials are also possible under this laser-incurred condition via which metastable materials with high performance for energy-related applications can be produced.…”

Ablation and Patterning of Carbon Nanotube Film by Femtosecond Laser Irradiation

“…The large thermal stress caused by the laser irradiated on the CNT film will induce damage to the material, which may lead to complex structural modifications or even a conversion to other polymers [25]. Based on the analysis of the effect of laser parameters on the material, the surface morphology of the hole and the shape of the inner wall were mainly caused by the involved interaction mechanisms between the ultra-short pulse laser and the material.…”