| AVS 66th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Thursday Sessions |
| Session PS+SS-ThA |
| Session: | Plasma Conversion and Enhanced Catalysis for Chemical Synthesis |
| Presenter: | Takeshi Kitajima, National Defense Academy, Japan |
| Authors: | T. Kitajima, National Defense Academy, Japan T. Nakano, National Defense Academy, Japan |
| Correspondent: | Click to Email |
In this study, we compared the degree of nitridation according to the presence or absence of ion irradiation (I), light irradiation from plasma (L) and the presence or absence of gold nanoparticle catalyst (C), respectively, and discovered the presence of radical nitriding by surface plasmon resonance of gold nanoparticles.
Gold is deposited for 2 minutes by electron beam evaporation on graphite crystals in an ultra-high vacuum chamber.
It was found by AFM measurement that gold nanoparticles with a diameter of about 20 nm were formed on the graphite crystal surface by aggregation.
Next, NH3-Ar (1: 3) mixed plasma (ICP, 70 MHz, 100 W) at a pressure of 10 Pa was generated in the plasma chamber. The sample was irradiated for 10 minutes with radicals and light that passed directly or through a 30 line/inch SUS304 single mesh.
The atomic composition by XPS was examined for each irradiation condition. It was found that in the condition RLC where gold nanoparticles were generated and irradiated with radicals and light, nitridation was promoted about twice as much as plasma irradiation.
It is speculated that irradiation of gold nanoparticles with light excites plasmons to promote the nitridation reaction.
Next, Raman scattering analysis of graphene nitride was performed. Islands found on graphite were considered as graphene. Among the Raman scattering spectra, the component intensities of 2D (2690 cm -1), G (1580 cm -1) and D (1350 cm -1) were measured to evaluate the intensity ratio.
Under RLC conditions, the I2D / IG ratio has not dropped significantly. It can be seen that the structural change of the graphene island due to ion bombardment is prevented. Furthermore, the ID / IG ratio is higher than in plasma irradiation (RIL), and it can be confirmed that nitrogen doping has progressed more. From the above, it is considered that the catalytic activity of the gold nanoparticles is expressed by the effect of surface plasmon excitation, and the formation of graphene nitride with low damage by radicals becomes possible.
1. Haibo Wang, Thandavarayan Maiyalagan, and Xin Wang, ACS Catalysis 2, 781 (2012).
2. Marie-Christine Daniel and Didier Astruc, Chemical Reviews 104, 293 (2004).