Laser photolysis of liquid benzene and toluene: Graphitic and polymeric carbon formation at ambient temperature Original Research Article

ArF laser photolysis of liquid benzene and toluene yields hydrogen, methane, ethene, ethyne, aromatic hydrocarbons and carbon. The preponderance of biphenyl among the aromatic products from photolysis of benzene, and that of bibenzyl among those from photolysis of toluene reveals the importance of the phenyl and benzyl radical combinations in the initial stages of photolysis. XPS and Raman spectroscopies showed the carbon to contain both sp3 and sp2 components and to consist of graphitic and polymeric constituents. The remarkable feature is that the carbon formation occurs at ambient temperature of the irradiated liquids; photolytic graphitization modes must therefore be different from those involved in thermally-induced graphitization which takes place at temperatures above 2500.