Preparation of N-doped Hollow Carbon Spheres and Investigation of Their Optical Properties

N-doped hollow carbon spheres (NDHCSs) were prepared by DC arc discharge at 800°C in nitrogen, using anode prepared by the filling method. The morphology, structure, chemical and phase compositions, and optical properties of the product deposited on the stainless steel sheet were characterized by using FESEM, HRTEM, EDX, EELS, XRD, and UV-Vis, respectively. The results show that the outer diameters of the NDHCSs are in the range of 110–543 nm and their wall thicknesses are in the range of 2–12 nm. The walls consist of two parts, namely, the inner part and the outside part, which are comparatively complete structure of graphite and discontinuously wave-like structure of layer, respectively. The NDHCSs consist of C, N and O elements with comparatively uniform distribution. The phase composition of NDHCSs mainly includes graphitic carbon and another carbon phase. The UV-Vis spectra of the suspensions of the NDHCSs in ethanol show three absorption peaks at 210 nm, 221 nm and 264 nm. Such suspension emits green luminescence under UV light irradiation and can keep stable at least for two months. The NDHCSs may have potential application in the field of optics.