Laser ablation synthesis of newgold carbides. From gold-diamond nano-composite as a precursor to gold-doped diamonds. Time-of-flight mass spectrometric study

RATIONALEGold carbides can be produced via laser ablation synthesis (LAS) from mixtures of nano-gold (NG) and various carbonaceous materials. The nano-composite of nano-gold (NG) and nano-diamond (ND) might represent a promising precursor for the generation of new gold carbides. METHODSTime-of-flight mass spectrometry (TOF MS), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) were used. The stoichiometry of clusters was determined via modelling of the isotopic patterns and MSn analysis. RESULTSA simple procedure for the preparation of ND-NG nano-composite was developed using NG and ND. The formation of AuCn+ (n=1-11, 18), Au2Cn+ (n=1-16) and Au3Cn+ (n=1-10) clusters during LAS of the nano-composite was proved. Structures of gold carbides are proposed and discussed. Diamonds-containing AumCn+ (m=1-3, n=10, 14, 18, 22) clusters might be not carbides but endohedral supramolecular complexes Au-m@C-n(+) i.e., 'gold-doped' diamonds. CONCLUSIONSTOF MS was shown to be a useful technique for following the formation of gold carbides in the gas phase. Clusters and 'gold-doped' diamonds generated might inspire synthesis of new Au-C materials with hardly predictable, unusual properties. Copyright (c) 2013 John Wiley & Sons, Ltd.