Jan 16, 2013
Laser beam exfoliates graphite to form chemically tunable platform
Reporting their results in the journal Nanotechnology, scientists from the University of Catania and the Italian National Research Council (CNR) have developed a single-step, scalable and green strategy to obtain reduced graphene oxide (GO) layers in water that involves irradiating carbon targets with nanosecond laser pulses. The layers spontaneously migrate at the water–air interface, forming sheets of several tens of micrometres and show intense ultraviolet photoluminescence.
Although traditionally seen as a precursor to large-scale graphene synthesis, GO has recently received more attention for its other possible uses. For example, it is considered as a chemically tunable platform for optical applications and has uses in biosensing and photothermal therapy.
In the study, the process was observed to be very efficient in terms of production rate and provides an alternative method to mechanical or chemical exfoliation. To their surprise, the researchers witnessed that very large GO sheets spontaneously migrate at the water surface to produce a free-standing membrane at the water–air interface.
The method indicates a scalable approach for GO production, providing high quality and controllable macroscopic samples for the exploration of novel properties and the development of new applications. In particular, these unique conditions offer an intriguing environment where opposing dielectric media meet and molecular interactions such as hydrogen bonding and electrostatic interactions are greatly enhanced.
Additional information can be found in the journal Nanotechnology.
About the author
The study was conducted by researchers from the Department of Chemistry at the University of Catania (Italy) and the Italian National Council for Research (CNR-IMM). The teams are working together on the synthesis and characterization of carbon-based nanomaterials, focusing on applications in the fields of microelectronics and sensors. Prof. Giuseppe Compagnini, group leader at the University of Catania, has strong interests in nanomaterials and nanostructures obtained using laser and plasma processes in liquid environments. Dr Silvia Scalese is in charge of the SEM and the carbon nanostructures laboratories at the CNR-IMM. She has deep experience in the characterization of materials by SEM as well as the synthesis of carbon-based nanostructures.