Hydrogenated Si-O-C nanoparticles: Synthesis, structure, and thermodynamic stability

In the present work, for the first time, the inorganic Si-based materials lacking preexisting mixed bonds (O-Si-C, silicon in tetrahedral coordination bonded to both carbon and oxygen) have been successfully used as starting materials in a laser evaporation/condensation system for making hydrogenated silicon oxycarbide (Si-O-C-H) nanoparticles containing mixed bonds. The obtained materials are characterized by spectroscopic, microscopic, and calorimetric measurements. Thermodynamically stable 5-10 nm amorphous Si-O-C-H particles with a complex structure containing a combination of pure and mixed Si-based tetrahedral units (SiO _iC_4-i; i = 0-4), and a considerable amount of Si-OH and C-H bonds have been synthesized. The nanoparticles possess high surface areas (428-467 m²/g), suggesting potential use in functionalities requiring high surface to volume ratios. In addition, making thermodynamically stable Si-O-C-H ceramics using a pathway different from the polymer route raises the likelihood of formation of similar carbon containing compounds in the planetary accretion and the Earth's interior.