Vertically aligned binary CN nanocone (CNNC) arrays were prepared by a direct-current abnormal glow discharge plasma-assisted reaction deposition method. CNNCs were grown on silicon wafers covered by Ni intermediate layers.The experiments were carried out in environments of methane and nitrogen mixtures, with a total pressure of 5 Torr and CH 4 /N 2 pressure ratios of 1/50 to 1/10. As-grown short CNNCs can have tip diameter of curvature of only 2 nm to 3 nm and are mainly crystalline b-C 3 N 4 , while long CNNCs are mainly amorphous with inclusions of b-C 3 N 4 -coated Ni crystals. Based on characterization and analysis of the as-grown binary CN nanostructures, their growth mechanism is proposed and discussed.

No abstract

The properties of plasmas in a CH4∕N2 dc abnormal glow discharge with the percentage of methane from 1% to 20% have been studied in order to understand the effect of precursor incorporation into the carbon nitride (CNx) films. The appearance of CN radicals as well as C2, CH, and NH has been revealed by optical emission spectroscopy (OES). The evolution of CN, N2, N2+, and C2 emission lines from mixed CH4∕N2 and pure N2 plasma on changing mixture ratio and polarity of discharge-field has been studied. The possible mechanisms behind their variations have been discussed. Besides, a CH4∕N2 ratio of 1∕50 and a top-needle anode is considered to be the best conditions for synthesis of β-C3N4, which has been confirmed in the as-deposited carbon nitride films with quite good crystalline features by XRD analyses.

No abstract

No abstract