Surface chemistry of nanocarbon: Characterization strategies from the viewpoint of catalysis and energy conversion

The applications of nanocarbon materials have been drawing an ever-increasing attention due to their unique physical and chemical properties. The performance of nanocarbon materials is determined or significantly influenced by their surface chemical composition and structure, including edges, holes, heteroatoms and functional groups etc. As a result, the accurate characterization and interpretation of the surface chemical properties of nanocarbon is extremely important, and numerous mature techniques were developed with the rapid progress of nanotechnology and characteristic instrumentation. In this review we summarized the latest development of characterization techniques for nanocarbon materials, the principles behind the techniques and the related data analysis methods. The characterization techniques are divided into four categories, including spectroscopy (IR, Raman, XPS, UPS, XAS, NMR and EELS), surface reaction (Boehm titration, potentiometric titration, chemical titration and TPSR), electron/probe microscopy (TEM, SEM, STM and AFM) and electro-chemistry methods. The most suitable application circumstances, test conditions and chemical information derivable by each characterization method are pointed out with examples, and the advantages and shortcomings of each technique are thoroughly discussed. We express the idea that full-scale structural information of nanocarbon could only be obtained by proper and comprehensive application of multiple kinds of characterization methods.