Characterization of oxidized carbon materials with photoinduced absorption response

An efficient application of fast remote diagnostics for carbon material (CM) bulk particles was demonstrated. Porous layers of CM particles with different oxidation levels were characterized by self-action of picosecond laser pulses at 1064 nm. Nitrogen adsorption, Boehm titration, and thermal analysis of the oxidized CMs revealed diverse specific surface area S BET , reasonable surface acidity, and high concentration of surface oxygen-containing groups. Dense CM porous layers showed a monotonous reduction of the absorptive nonlinear optical (NLO) response efficiency versus the oxidation level with characteristic magnitude Im( χ C ( 3 ) ) ∼ 10 - 10 esu for the carbon particles fraction. The obtained Im( χ C ( 3 ) ) / S BET ratio remains approximately constant, which indicates the certain proportion between the absorptive NLO response efficiency and the specific surface area. We suggest to use Im( χ C ( 3 ) ) as a figure of merit for carbons subjected to the oxidation—the route to enhance the CM surface reactivity.