Effect of nitrogen doping on wetting and photoactive properties of laser processed zinc oxide-graphene oxide nanocomposite layers

Abstract

Zinc oxide-graphene oxide nanocomposite layers were submitted to laser irradiation in air or controlled nitrogen atmosphere using a frequency quadrupled Nd:YAG (λ = 266 nm, τFWHM ≅ 3 ns, ν = 10 Hz) laser source. The experiments were performed in air at atmospheric pressure or in nitrogen at a pressure of 2 × 104 Pa. The effect of the irradiation conditions, incident laser fluence value, and number of subsequent laser pulses on the surface morphology of the composite material was systematically investigated. The obtained results reveal that nitrogen incorporation improves significantly the wetting and photoactive properties of the laser processed layers. The kinetics of water contact angle variation when the samples are submitted to laser irradiation in nitrogen are faster than that of the samples irradiated in air, the surfaces becoming super-hydrophilic under UV light irradiation.

Laser-induced chemical transformation of graphene oxide–iron oxide nanoparticles composites deposited on polymer substrates

“…1b). Coalescence between molten NPs prior their resolidification process would be also present, as already observed during irradiation of GO-ZnO NPs composites [20]. This effect is clearly witnessed after the accumulation of 1000 pulses with 40 mJ cm À2 fluence, but just after 10 pulses with 100 mJ cm À2 .…”

“…Laser-induced development of ripple-like structures in GO material has been already reported [20,28]. UV radiation not only generates very rapid temperature variations in the material (Fig.…”

“…Thus, it is necessary to develop environmentfriendly methods for the preparation of these types of materials. Conversely, laser irradiation techniques have recently emerged as versatile, scalable, eco-friendly and easy ways for fabricating thin films composed of rGO-metal oxide nanostructures either by direct irradiation [20] or laser deposition [21,22] methods. Remarkably, the nature of ultraviolet pulsed laser radiation could lead to the attainment of new chemical pathways for the development of graphene-based nanocomposites with improved functionalities to be used in future devices.…”

Synthesis of graphene-based photocatalysts for water splitting by laser-induced doping with ionic liquids

“…Finally, the peak at 2950 cm -1 (attributed to CH 2 groups) suggests the presence of alkyl chains in the modified GO structure, most likely originating from [bmim] molecules. effects [16,20,43,[54][55][56]. Conversely, it is known that imidazolium-based molecules are cationic and possess large electron affinities and π-conjugated orbitals [57].…”

MAPLE synthesis of reduced graphene oxide/silver nanocomposite electrodes: Influence of target composition and gas ambience

“…Lastly, rGO can be functionalized through the incorporation of nitrogen species conferring different properties such as switching from p-to n-type semiconductor [14]. Besides the interest in standalone GO, there is great attention in the development of GO nanocomposite films with either metal (e.g., Ni, Au) or metal oxides nanoparticles (e.g., NiO, TiO 2 , SnO 2 , Fe 3 O 4 , MnO 2 ) that combine both the properties of GO and the nanoparticles (NPs) enhancing their performance for applications in photocatalysis, supercapacitors, electrochemistry, water-splitting, etc [15][16][17][18][19][20][21][22][23]. Recently, (r)GO-Ag composites are attracting high research interest due to their multifunctional properties and wide range of applications.…”