Page 79 - Synthesis of Functional Nanoparticles Using an Atmospheric Pressure Microplasma Process - LiangLiang Lin

Titanium Nitride Nanoparticles Synthesis - an Advanced Model Study towards Nitride Nanomaterial
(b) 35 30 25 20 15 10 5
06 7 8 9 10 11 12 13 14 15 16 Particle size (nm)
Figure 4.5 (a) TEM, (b) size distribution histogram, (c) HRTEM and (d) SAED images of nanoparticles synthesized at condition 1
The crystalline structures of synthesized nanoparticles are further analyzed by XRD. It was also studied, how various partial concentrations of H2 in the gas mixture there are influencing the products properties. Figure 4.6 shows XRD patterns of nanoparticles prepared at different H2 concentrations, corresponding to condition 1 to condition 5 respectively. Prominent peaks at 2θ values of 36.7◦, 42.6◦, 61.8◦, 74.1◦ and 78.0◦ are clearly shown under all treatment conditions, which are indexed to (1 1 1), (2 0 0), (2 2 0), (3 1 1) and (2 2 2) crystal planes of TiN nanoparticles (JCPDS PDF card #38-1420), further confirming the preparation of TiN nanoparticles by the microplasma process. In addition to TiN nanoparticles, less intensive peaks of anatase phase TiO2 nanoparticles (JCPDS PDF card #21-1272) at 25.3◦ (1 0 1), 48.0◦ (2 0 0), 53.9◦ (1 0 5) as well as rutile phase TiO2 nanoparticles (JCPDS PDF card #21-1276) at 27.4◦ (1 1 0), 41.2◦ (1 1 1), 44.4◦ (2 1 0) are also observed, indicating the formation of TiO2. Besides, the additional admixture of H2 into the plasma results in an apparent decrease of both TiO2 (anatase) and TiO2 (rutile) peaks as well as the relative intensity ratio (RIR) between TiO2 and TiN components. As a semi-quantitative method, the decreased RIR of TiO2 to TiN reveals that oxidization phenomenon is suppressed with H2 concentrations.32 While the oxide reduction effect by hydrogen is well-known, the atomic hydrogen radicals
Gaussian fit
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Frequency (%)