Laser-induced breakdown spectroscopy: an advanced method for analysis of nanocarbon materials chemical composition†
The precise and express analysis of nanocarbon materials chemistry continues to be one of the key tasks in the study and the application of these unique structures. Despite the large variety of analytical techniques that have been commonly used for this purpose, the development of new methods that will further expand the efficiency of nanocarbon material characterization is still needed. Herein, the applicability of laser-induced breakdown spectroscopy (LIBS) towards studying the chemical composition of different types of nanocarbon structures was investigated. Graphene oxide, reduced graphene oxide (analogous of pristine graphene) and detonation nanodiamonds were chosen as the most attractive representatives of nanocarbon materials. The as-obtained results demonstrate that the functionalization parameters, such as the functionalization degree and predominant type of the functional groups, can be effectively determined on the basis of the analyzed plasma emission spectra. Furthermore, the presence of various inorganic contaminants can be identified using the LIBS technique. When compared to conventional approaches that study samples in the form of thick pellets, thin films of nanocarbon structures on various substrates were successfully analyzed using the LIBS technique. Several experimental features arise in this case, in particular, the possible ablation of wafer and formation of a thermal emission background. To overcome these challenges and to obtain reliable informative spectra, adjustment of the ablation parameters and additional spectra processing procedures were applied. As a result, the LIBS method can be a valuable and simple tool for quality control and the characterization of various nanocarbon structures.